class Sequel::Database
A Database
object represents a virtual connection to a database. The Database
class is meant to be subclassed by database adapters in order to provide the functionality needed for executing queries.
Constants
- OPTS
1 - Methods that execute queries and/or return results
↑ topConstants
- COLUMN_SCHEMA_DATETIME_TYPES
- COLUMN_SCHEMA_STRING_TYPES
Attributes
Whether the schema should be cached for this database. True by default for performance, can be set to false to always issue a database query to get the schema.
The prepared statement object hash for this database, keyed by name symbol
Public Instance Methods
Runs the supplied SQL
statement string on the database server. Returns self so it can be safely chained:
DB << "UPDATE albums SET artist_id = NULL" << "DROP TABLE artists"
# File lib/sequel/database/query.rb 25 def <<(sql) 26 run(sql) 27 self 28 end
Call the prepared statement with the given name with the given hash of arguments.
DB[:items].where(id: 1).prepare(:first, :sa) DB.call(:sa) # SELECT * FROM items WHERE id = 1
# File lib/sequel/database/query.rb 35 def call(ps_name, hash=OPTS, &block) 36 prepared_statement(ps_name).call(hash, &block) 37 end
Method that should be used when submitting any DDL (Data Definition Language) SQL
, such as create_table
. By default, calls execute_dui
. This method should not be called directly by user code.
# File lib/sequel/database/query.rb 42 def execute_ddl(sql, opts=OPTS, &block) 43 execute_dui(sql, opts, &block) 44 end
Method that should be used when issuing a DELETE or UPDATE statement. By default, calls execute. This method should not be called directly by user code.
# File lib/sequel/database/query.rb 49 def execute_dui(sql, opts=OPTS, &block) 50 execute(sql, opts, &block) 51 end
Method that should be used when issuing a INSERT statement. By default, calls execute_dui. This method should not be called directly by user code.
# File lib/sequel/database/query.rb 56 def execute_insert(sql, opts=OPTS, &block) 57 execute_dui(sql, opts, &block) 58 end
Returns a single value from the database, see Dataset#get
.
DB.get(1) # SELECT 1 # => 1 DB.get{server_version.function} # SELECT server_version()
# File lib/sequel/database/query.rb 65 def get(*args, &block) 66 @default_dataset.get(*args, &block) 67 end
Runs the supplied SQL
statement string on the database server. Returns nil. Options:
- :server
-
The server to run the
SQL
on.
DB.run("SET some_server_variable = 42")
# File lib/sequel/database/query.rb 74 def run(sql, opts=OPTS) 75 sql = literal(sql) if sql.is_a?(SQL::PlaceholderLiteralString) 76 execute_ddl(sql, opts) 77 nil 78 end
Returns the schema for the given table as an array with all members being arrays of length 2, the first member being the column name, and the second member being a hash of column information. The table argument can also be a dataset, as long as it only has one table. Available options are:
- :reload
-
Ignore any cached results, and get fresh information from the database.
- :schema
-
An explicit schema to use. It may also be implicitly provided via the table name.
If schema parsing is supported by the database, the column information hash should contain at least the following entries:
- :allow_null
-
Whether NULL is an allowed value for the column.
- :db_type
-
The database type for the column, as a database specific string.
- :default
-
The database default for the column, as a database specific string, or nil if there is no default value.
- :primary_key
-
Whether the columns is a primary key column. If this column is not present, it means that primary key information is unavailable, not that the column is not a primary key.
- :ruby_default
-
The database default for the column, as a ruby object. In many cases, complex database defaults cannot be parsed into ruby objects, in which case nil will be used as the value.
- :type
-
A symbol specifying the type, such as :integer or :string.
Example:
DB.schema(:artists) # [[:id, # {:type=>:integer, # :primary_key=>true, # :default=>"nextval('artist_id_seq'::regclass)", # :ruby_default=>nil, # :db_type=>"integer", # :allow_null=>false}], # [:name, # {:type=>:string, # :primary_key=>false, # :default=>nil, # :ruby_default=>nil, # :db_type=>"text", # :allow_null=>false}]]
# File lib/sequel/database/query.rb 121 def schema(table, opts=OPTS) 122 raise(Error, 'schema parsing is not implemented on this database') unless supports_schema_parsing? 123 124 opts = opts.dup 125 tab = if table.is_a?(Dataset) 126 o = table.opts 127 from = o[:from] 128 raise(Error, "can only parse the schema for a dataset with a single from table") unless from && from.length == 1 && !o.include?(:join) && !o.include?(:sql) 129 table.first_source_table 130 else 131 table 132 end 133 134 qualifiers = split_qualifiers(tab) 135 table_name = qualifiers.pop 136 sch = qualifiers.pop 137 information_schema_schema = case qualifiers.length 138 when 1 139 Sequel.identifier(*qualifiers) 140 when 2 141 Sequel.qualify(*qualifiers) 142 end 143 144 if table.is_a?(Dataset) 145 quoted_name = table.literal(tab) 146 opts[:dataset] = table 147 else 148 quoted_name = schema_utility_dataset.literal(table) 149 end 150 151 opts[:schema] = sch if sch && !opts.include?(:schema) 152 opts[:information_schema_schema] = information_schema_schema if information_schema_schema && !opts.include?(:information_schema_schema) 153 154 Sequel.synchronize{@schemas.delete(quoted_name)} if opts[:reload] 155 if v = Sequel.synchronize{@schemas[quoted_name]} 156 return v 157 end 158 159 cols = schema_parse_table(table_name, opts) 160 raise(Error, "schema parsing returned no columns, table #{table_name.inspect} probably doesn't exist") if cols.nil? || cols.empty? 161 162 primary_keys = 0 163 auto_increment_set = false 164 cols.each do |_,c| 165 auto_increment_set = true if c.has_key?(:auto_increment) 166 primary_keys += 1 if c[:primary_key] 167 end 168 169 cols.each do |_,c| 170 c[:ruby_default] = column_schema_to_ruby_default(c[:default], c[:type]) unless c.has_key?(:ruby_default) 171 if c[:primary_key] && !auto_increment_set 172 # If adapter didn't set it, assume that integer primary keys are auto incrementing 173 c[:auto_increment] = primary_keys == 1 && !!(c[:db_type] =~ /int/io) 174 end 175 if !c[:max_length] && c[:type] == :string && (max_length = column_schema_max_length(c[:db_type])) 176 c[:max_length] = max_length 177 end 178 end 179 schema_post_process(cols) 180 181 Sequel.synchronize{@schemas[quoted_name] = cols} if cache_schema 182 cols 183 end
Returns true if a table with the given name exists. This requires a query to the database.
DB.table_exists?(:foo) # => false # SELECT NULL FROM foo LIMIT 1
Note that since this does a SELECT from the table, it can give false negatives if you don't have permission to SELECT from the table.
# File lib/sequel/database/query.rb 193 def table_exists?(name) 194 sch, table_name = schema_and_table(name) 195 name = SQL::QualifiedIdentifier.new(sch, table_name) if sch 196 ds = from(name) 197 transaction(:savepoint=>:only){_table_exists?(ds)} 198 true 199 rescue DatabaseError 200 false 201 end
Private Instance Methods
Uncached version of metadata_dataset
, designed for overriding.
# File lib/sequel/database/query.rb 291 def _metadata_dataset 292 dataset 293 end
Should raise an error if the table doesn't not exist, and not raise an error if the table does exist.
# File lib/sequel/database/query.rb 207 def _table_exists?(ds) 208 ds.get(SQL::AliasedExpression.new(Sequel::NULL, :nil)) 209 end
Whether the type should be treated as a string type when parsing the column schema default value.
# File lib/sequel/database/query.rb 213 def column_schema_default_string_type?(type) 214 COLUMN_SCHEMA_STRING_TYPES.include?(type) 215 end
Transform the given normalized default string into a ruby object for the given type.
# File lib/sequel/database/query.rb 219 def column_schema_default_to_ruby_value(default, type) 220 case type 221 when :boolean 222 case default 223 when /[f0]/i 224 false 225 when /[t1]/i 226 true 227 end 228 when :string, :enum, :set, :interval 229 default 230 when :blob 231 Sequel::SQL::Blob.new(default) 232 when :integer 233 Integer(default) 234 when :float 235 Float(default) 236 when :date 237 Sequel.string_to_date(default) 238 when :datetime 239 DateTime.parse(default) 240 when :time 241 Sequel.string_to_time(default) 242 when :decimal 243 BigDecimal(default) 244 end 245 end
Look at the db_type and guess the maximum length of the column. This assumes types such as varchar(255).
# File lib/sequel/database/query.rb 277 def column_schema_max_length(db_type) 278 if db_type =~ /\((\d+)\)/ 279 $1.to_i 280 end 281 end
Normalize the default value string for the given type and return the normalized value.
# File lib/sequel/database/query.rb 249 def column_schema_normalize_default(default, type) 250 if column_schema_default_string_type?(type) 251 return unless m = /\A'(.*)'\z/.match(default) 252 m[1].gsub("''", "'") 253 else 254 default 255 end 256 end
Convert the given default, which should be a database specific string, into a ruby object.
# File lib/sequel/database/query.rb 260 def column_schema_to_ruby_default(default, type) 261 return default unless default.is_a?(String) 262 if COLUMN_SCHEMA_DATETIME_TYPES.include?(type) 263 if /now|today|CURRENT|getdate|\ADate\(\)\z/i.match(default) 264 if type == :date 265 return Sequel::CURRENT_DATE 266 else 267 return Sequel::CURRENT_TIMESTAMP 268 end 269 end 270 end 271 default = column_schema_normalize_default(default, type) 272 column_schema_default_to_ruby_value(default, type) rescue nil 273 end
Return a Method object for the dataset's output_identifier_method. Used in metadata parsing to make sure the returned information is in the correct format.
# File lib/sequel/database/query.rb 286 def input_identifier_meth(ds=nil) 287 (ds || dataset).method(:input_identifier) 288 end
Return a dataset that uses the default identifier input and output methods for this database. Used when parsing metadata so that column symbols are returned as expected.
# File lib/sequel/database/query.rb 298 def metadata_dataset 299 @metadata_dataset ||= _metadata_dataset 300 end
Return a Method object for the dataset's output_identifier_method. Used in metadata parsing to make sure the returned information is in the correct format.
# File lib/sequel/database/query.rb 305 def output_identifier_meth(ds=nil) 306 (ds || dataset).method(:output_identifier) 307 end
Remove the cached schema for the given schema name
# File lib/sequel/database/query.rb 310 def remove_cached_schema(table) 311 cache = @default_dataset.send(:cache) 312 Sequel.synchronize{cache.clear} 313 k = quote_schema_table(table) 314 Sequel.synchronize{@schemas.delete(k)} 315 end
Match the database's column type to a ruby type via a regular expression, and return the ruby type as a symbol such as :integer or :string.
# File lib/sequel/database/query.rb 320 def schema_column_type(db_type) 321 case db_type 322 when /\A(character( varying)?|n?(var)?char|n?text|string|clob)/io 323 :string 324 when /\A(int(eger)?|(big|small|tiny)int)/io 325 :integer 326 when /\Adate\z/io 327 :date 328 when /\A((small)?datetime|timestamp( with(out)? time zone)?)(\(\d+\))?\z/io 329 :datetime 330 when /\Atime( with(out)? time zone)?\z/io 331 :time 332 when /\A(bool(ean)?)\z/io 333 :boolean 334 when /\A(real|float( unsigned)?|double( precision)?|double\(\d+,\d+\)( unsigned)?)\z/io 335 :float 336 when /\A(?:(?:(?:num(?:ber|eric)?|decimal)(?:\(\d+,\s*(\d+|false|true)\))?))\z/io 337 $1 && ['0', 'false'].include?($1) ? :integer : :decimal 338 when /bytea|blob|image|(var)?binary/io 339 :blob 340 when /\Aenum/io 341 :enum 342 end 343 end
Post process the schema values.
# File lib/sequel/database/query.rb 346 def schema_post_process(cols) 347 if RUBY_VERSION >= '2.5' 348 cols.each do |_, h| 349 db_type = h[:db_type] 350 if db_type.is_a?(String) 351 h[:db_type] = -db_type 352 end 353 end 354 end 355 356 cols.each do |_,c| 357 c.each_value do |val| 358 val.freeze if val.is_a?(String) 359 end 360 end 361 end
2 - Methods that modify the database schema
↑ topConstants
- COLUMN_DEFINITION_ORDER
The order of column modifiers to use when defining a column.
- COMBINABLE_ALTER_TABLE_OPS
The alter table operations that are combinable.
Public Instance Methods
Adds a column to the specified table. This method expects a column name, a datatype and optionally a hash with additional constraints and options:
DB.add_column :items, :name, String, unique: true, null: false DB.add_column :items, :category, String, default: 'ruby'
See alter_table
.
# File lib/sequel/database/schema_methods.rb 25 def add_column(table, *args) 26 alter_table(table) {add_column(*args)} 27 end
Adds an index to a table for the given columns:
DB.add_index :posts, :title DB.add_index :posts, [:author, :title], unique: true
Options:
- :ignore_errors
-
Ignore any DatabaseErrors that are raised
- :name
-
Name to use for index instead of default
See alter_table
.
# File lib/sequel/database/schema_methods.rb 40 def add_index(table, columns, options=OPTS) 41 e = options[:ignore_errors] 42 begin 43 alter_table(table){add_index(columns, options)} 44 rescue DatabaseError 45 raise unless e 46 end 47 nil 48 end
Alters the given table with the specified block. Example:
DB.alter_table :items do add_column :category, String, default: 'ruby' drop_column :category rename_column :cntr, :counter set_column_type :value, Float set_column_default :value, 4.2 add_index [:group, :category] drop_index [:group, :category] end
Note that add_column
accepts all the options available for column definitions using create_table
, and add_index
accepts all the options available for index definition.
See Schema::AlterTableGenerator
and the “Migrations and Schema Modification” guide.
# File lib/sequel/database/schema_methods.rb 67 def alter_table(name, &block) 68 generator = alter_table_generator(&block) 69 remove_cached_schema(name) 70 apply_alter_table_generator(name, generator) 71 nil 72 end
Return a new Schema::AlterTableGenerator
instance with the receiver as the database and the given block.
# File lib/sequel/database/schema_methods.rb 76 def alter_table_generator(&block) 77 alter_table_generator_class.new(self, &block) 78 end
Create a join table using a hash of foreign keys to referenced table names. Example:
create_join_table(cat_id: :cats, dog_id: :dogs) # CREATE TABLE cats_dogs ( # cat_id integer NOT NULL REFERENCES cats, # dog_id integer NOT NULL REFERENCES dogs, # PRIMARY KEY (cat_id, dog_id) # ) # CREATE INDEX cats_dogs_dog_id_cat_id_index ON cats_dogs(dog_id, cat_id)
The primary key and index are used so that almost all operations on the table can benefit from one of the two indexes, and the primary key ensures that entries in the table are unique, which is the typical desire for a join table.
The default table name this will create is the sorted version of the two hash values, joined by an underscore. So the following two method calls create the same table:
create_join_table(cat_id: :cats, dog_id: :dogs) # cats_dogs create_join_table(dog_id: :dogs, cat_id: :cats) # cats_dogs
You can provide column options by making the values in the hash be option hashes, so long as the option hashes have a :table entry giving the table referenced:
create_join_table(cat_id: {table: :cats, type: :Bignum}, dog_id: :dogs)
You can provide a second argument which is a table options hash:
create_join_table({cat_id: :cats, dog_id: :dogs}, temp: true)
Some table options are handled specially:
- :index_options
-
The options to pass to the index
- :name
-
The name of the table to create
- :no_index
-
Set to true not to create the second index.
- :no_primary_key
-
Set to true to not create the primary key.
# File lib/sequel/database/schema_methods.rb 119 def create_join_table(hash, options=OPTS) 120 keys = hash.keys.sort 121 create_table(join_table_name(hash, options), options) do 122 keys.each do |key| 123 v = hash[key] 124 unless v.is_a?(Hash) 125 v = {:table=>v} 126 end 127 v[:null] = false unless v.has_key?(:null) 128 foreign_key(key, v) 129 end 130 primary_key(keys) unless options[:no_primary_key] 131 index(keys.reverse, options[:index_options] || OPTS) unless options[:no_index] 132 end 133 nil 134 end
Forcibly create a join table, attempting to drop it if it already exists, then creating it.
# File lib/sequel/database/schema_methods.rb 137 def create_join_table!(hash, options=OPTS) 138 drop_table?(join_table_name(hash, options)) 139 create_join_table(hash, options) 140 end
Creates the join table unless it already exists.
# File lib/sequel/database/schema_methods.rb 143 def create_join_table?(hash, options=OPTS) 144 if supports_create_table_if_not_exists? && options[:no_index] 145 create_join_table(hash, options.merge(:if_not_exists=>true)) 146 elsif !table_exists?(join_table_name(hash, options)) 147 create_join_table(hash, options) 148 end 149 end
Creates a view, replacing a view with the same name if one already exists.
DB.create_or_replace_view(:some_items, "SELECT * FROM items WHERE price < 100") DB.create_or_replace_view(:some_items, DB[:items].where(category: 'ruby'))
For databases where replacing a view is not natively supported, support is emulated by dropping a view with the same name before creating the view.
# File lib/sequel/database/schema_methods.rb 239 def create_or_replace_view(name, source, options = OPTS) 240 if supports_create_or_replace_view? 241 options = options.merge(:replace=>true) 242 else 243 drop_view(name) rescue nil 244 end 245 246 create_view(name, source, options) 247 nil 248 end
Creates a table with the columns given in the provided block:
DB.create_table :posts do primary_key :id column :title, String String :content index :title end
General options:
- :as
-
Create the table using the value, which should be either a dataset or a literal
SQL
string. If this option is used, a block should not be given to the method. - :ignore_index_errors
-
Ignore any errors when creating indexes.
- :temp
-
Create the table as a temporary table.
MySQL
specific options:
- :charset
-
The character set to use for the table.
- :collate
-
The collation to use for the table.
- :engine
-
The table engine to use for the table.
PostgreSQL specific options:
- :on_commit
-
Either :preserve_rows (default), :drop or :delete_rows. Should only be specified when creating a temporary table.
- :foreign
-
Create a foreign table. The value should be the name of the foreign server that was specified in CREATE SERVER.
- :inherits
-
Inherit from a different table. An array can be specified to inherit from multiple tables.
- :unlogged
-
Create the table as an unlogged table.
- :options
-
The OPTIONS clause to use for foreign tables. Should be a hash where keys are option names and values are option values. Note that option names are unquoted, so you should not use untrusted keys.
- :tablespace
-
The tablespace to use for the table.
See Schema::CreateTableGenerator
and the “Schema Modification” guide.
# File lib/sequel/database/schema_methods.rb 187 def create_table(name, options=OPTS, &block) 188 remove_cached_schema(name) 189 if sql = options[:as] 190 raise(Error, "can't provide both :as option and block to create_table") if block 191 create_table_as(name, sql, options) 192 else 193 generator = options[:generator] || create_table_generator(&block) 194 create_table_from_generator(name, generator, options) 195 create_table_indexes_from_generator(name, generator, options) 196 end 197 nil 198 end
Forcibly create a table, attempting to drop it if it already exists, then creating it.
DB.create_table!(:a){Integer :a} # SELECT NULL FROM a LIMIT 1 -- check existence # DROP TABLE a -- drop table if already exists # CREATE TABLE a (a integer)
# File lib/sequel/database/schema_methods.rb 206 def create_table!(name, options=OPTS, &block) 207 drop_table?(name) 208 create_table(name, options, &block) 209 end
Creates the table unless the table already exists.
DB.create_table?(:a){Integer :a} # SELECT NULL FROM a LIMIT 1 -- check existence # CREATE TABLE a (a integer) -- if it doesn't already exist
# File lib/sequel/database/schema_methods.rb 216 def create_table?(name, options=OPTS, &block) 217 options = options.dup 218 generator = options[:generator] ||= create_table_generator(&block) 219 if generator.indexes.empty? && supports_create_table_if_not_exists? 220 create_table(name, options.merge!(:if_not_exists=>true)) 221 elsif !table_exists?(name) 222 create_table(name, options) 223 end 224 end
Return a new Schema::CreateTableGenerator
instance with the receiver as the database and the given block.
# File lib/sequel/database/schema_methods.rb 228 def create_table_generator(&block) 229 create_table_generator_class.new(self, &block) 230 end
Creates a view based on a dataset or an SQL
string:
DB.create_view(:cheap_items, "SELECT * FROM items WHERE price < 100") # CREATE VIEW cheap_items AS # SELECT * FROM items WHERE price < 100 DB.create_view(:ruby_items, DB[:items].where(category: 'ruby')) # CREATE VIEW ruby_items AS # SELECT * FROM items WHERE (category = 'ruby') DB.create_view(:checked_items, DB[:items].where(:foo), check: true) # CREATE VIEW checked_items AS # SELECT * FROM items WHERE foo # WITH CHECK OPTION
Options:
- :columns
-
The column names to use for the view. If not given, automatically determined based on the input dataset.
- :check
-
Adds a WITH CHECK OPTION clause, so that attempting to modify rows in the underlying table that would not be returned by the view is not allowed. This can be set to :local to use WITH LOCAL CHECK OPTION.
PostgreSQL/SQLite specific option:
- :temp
-
Create a temporary view, automatically dropped on disconnect.
PostgreSQL specific options:
- :materialized
-
Creates a materialized view, similar to a regular view, but backed by a physical table.
- :recursive
-
Creates a recursive view. As columns must be specified for recursive views, you can also set them as the value of this option. Since a recursive view requires a union that isn't in a subquery, if you are providing a
Dataset
as the source argument, if should probably call the union method with the all: true and from_self: false options. - :tablespace
-
The tablespace to use for materialized views.
# File lib/sequel/database/schema_methods.rb 286 def create_view(name, source, options = OPTS) 287 execute_ddl(create_view_sql(name, source, options)) 288 remove_cached_schema(name) 289 nil 290 end
Removes a column from the specified table:
DB.drop_column :items, :category
See alter_table
.
# File lib/sequel/database/schema_methods.rb 297 def drop_column(table, *args) 298 alter_table(table) {drop_column(*args)} 299 end
Removes an index for the given table and column(s):
DB.drop_index :posts, :title DB.drop_index :posts, [:author, :title]
See alter_table
.
# File lib/sequel/database/schema_methods.rb 307 def drop_index(table, columns, options=OPTS) 308 alter_table(table){drop_index(columns, options)} 309 end
Drop the join table that would have been created with the same arguments to create_join_table
:
drop_join_table(cat_id: :cats, dog_id: :dogs) # DROP TABLE cats_dogs
# File lib/sequel/database/schema_methods.rb 316 def drop_join_table(hash, options=OPTS) 317 drop_table(join_table_name(hash, options), options) 318 end
Drops one or more tables corresponding to the given names:
DB.drop_table(:posts) # DROP TABLE posts DB.drop_table(:posts, :comments) DB.drop_table(:posts, :comments, cascade: true)
# File lib/sequel/database/schema_methods.rb 325 def drop_table(*names) 326 options = names.last.is_a?(Hash) ? names.pop : OPTS 327 names.each do |n| 328 execute_ddl(drop_table_sql(n, options)) 329 remove_cached_schema(n) 330 end 331 nil 332 end
Drops the table if it already exists. If it doesn't exist, does nothing.
DB.drop_table?(:a) # SELECT NULL FROM a LIMIT 1 -- check existence # DROP TABLE a -- if it already exists
# File lib/sequel/database/schema_methods.rb 340 def drop_table?(*names) 341 options = names.last.is_a?(Hash) ? names.pop : OPTS 342 if supports_drop_table_if_exists? 343 options = options.merge(:if_exists=>true) 344 names.each do |name| 345 drop_table(name, options) 346 end 347 else 348 names.each do |name| 349 drop_table(name, options) if table_exists?(name) 350 end 351 end 352 nil 353 end
Drops one or more views corresponding to the given names:
DB.drop_view(:cheap_items) DB.drop_view(:cheap_items, :pricey_items) DB.drop_view(:cheap_items, :pricey_items, cascade: true) DB.drop_view(:cheap_items, :pricey_items, if_exists: true)
Options:
- :cascade
-
Also drop objects depending on this view.
- :if_exists
-
Do not raise an error if the view does not exist.
PostgreSQL specific options:
- :materialized
-
Drop a materialized view.
# File lib/sequel/database/schema_methods.rb 368 def drop_view(*names) 369 options = names.last.is_a?(Hash) ? names.pop : OPTS 370 names.each do |n| 371 execute_ddl(drop_view_sql(n, options)) 372 remove_cached_schema(n) 373 end 374 nil 375 end
Renames a column in the specified table. This method expects the current column name and the new column name:
DB.rename_column :items, :cntr, :counter
See alter_table
.
# File lib/sequel/database/schema_methods.rb 394 def rename_column(table, *args) 395 alter_table(table) {rename_column(*args)} 396 end
Renames a table:
DB.tables #=> [:items] DB.rename_table :items, :old_items DB.tables #=> [:old_items]
# File lib/sequel/database/schema_methods.rb 382 def rename_table(name, new_name) 383 execute_ddl(rename_table_sql(name, new_name)) 384 remove_cached_schema(name) 385 nil 386 end
Sets the default value for the given column in the given table:
DB.set_column_default :items, :category, 'perl!'
See alter_table
.
# File lib/sequel/database/schema_methods.rb 403 def set_column_default(table, *args) 404 alter_table(table) {set_column_default(*args)} 405 end
Set the data type for the given column in the given table:
DB.set_column_type :items, :price, :float
See alter_table
.
# File lib/sequel/database/schema_methods.rb 412 def set_column_type(table, *args) 413 alter_table(table) {set_column_type(*args)} 414 end
Private Instance Methods
# File lib/sequel/database/schema_methods.rb 452 def alter_table_add_column_sql(table, op) 453 "ADD COLUMN #{column_definition_sql(op)}" 454 end
# File lib/sequel/database/schema_methods.rb 476 def alter_table_add_constraint_sql(table, op) 477 "ADD #{constraint_definition_sql(op)}" 478 end
# File lib/sequel/database/schema_methods.rb 456 def alter_table_drop_column_sql(table, op) 457 "DROP COLUMN #{quote_identifier(op[:name])}#{' CASCADE' if op[:cascade]}" 458 end
# File lib/sequel/database/schema_methods.rb 480 def alter_table_drop_constraint_sql(table, op) 481 quoted_name = quote_identifier(op[:name]) if op[:name] 482 if op[:type] == :foreign_key 483 quoted_name ||= quote_identifier(foreign_key_name(table, op[:columns])) 484 end 485 "DROP CONSTRAINT #{quoted_name}#{' CASCADE' if op[:cascade]}" 486 end
The class used for alter_table
generators.
# File lib/sequel/database/schema_methods.rb 437 def alter_table_generator_class 438 Schema::AlterTableGenerator 439 end
SQL
fragment for given alter table operation.
# File lib/sequel/database/schema_methods.rb 442 def alter_table_op_sql(table, op) 443 meth = "alter_table_#{op[:op]}_sql" 444 if respond_to?(meth, true) 445 # Allow calling private methods as alter table op sql methods are private 446 send(meth, table, op) 447 else 448 raise Error, "Unsupported ALTER TABLE operation: #{op[:op]}" 449 end 450 end
# File lib/sequel/database/schema_methods.rb 460 def alter_table_rename_column_sql(table, op) 461 "RENAME COLUMN #{quote_identifier(op[:name])} TO #{quote_identifier(op[:new_name])}" 462 end
# File lib/sequel/database/schema_methods.rb 468 def alter_table_set_column_default_sql(table, op) 469 "ALTER COLUMN #{quote_identifier(op[:name])} SET DEFAULT #{literal(op[:default])}" 470 end
# File lib/sequel/database/schema_methods.rb 472 def alter_table_set_column_null_sql(table, op) 473 "ALTER COLUMN #{quote_identifier(op[:name])} #{op[:null] ? 'DROP' : 'SET'} NOT NULL" 474 end
# File lib/sequel/database/schema_methods.rb 464 def alter_table_set_column_type_sql(table, op) 465 "ALTER COLUMN #{quote_identifier(op[:name])} TYPE #{type_literal(op)}" 466 end
The SQL
to execute to modify the table. op should be one of the operations returned by the AlterTableGenerator.
# File lib/sequel/database/schema_methods.rb 490 def alter_table_sql(table, op) 491 case op[:op] 492 when :add_index 493 index_definition_sql(table, op) 494 when :drop_index 495 drop_index_sql(table, op) 496 else 497 "ALTER TABLE #{quote_schema_table(table)} #{alter_table_op_sql(table, op)}" 498 end 499 end
Array
of SQL
statements used to modify the table, corresponding to changes specified by the operations.
# File lib/sequel/database/schema_methods.rb 503 def alter_table_sql_list(table, operations) 504 if supports_combining_alter_table_ops? 505 grouped_ops = [] 506 last_combinable = false 507 operations.each do |op| 508 if combinable_alter_table_op?(op) 509 if sql = alter_table_op_sql(table, op) 510 grouped_ops << [] unless last_combinable 511 grouped_ops.last << sql 512 last_combinable = true 513 end 514 elsif sql = alter_table_sql(table, op) 515 Array(sql).each{|s| grouped_ops << s} 516 last_combinable = false 517 end 518 end 519 grouped_ops.map do |gop| 520 if gop.is_a?(Array) 521 "ALTER TABLE #{quote_schema_table(table)} #{gop.join(', ')}" 522 else 523 gop 524 end 525 end 526 else 527 operations.map{|op| alter_table_sql(table, op)}.flatten.compact 528 end 529 end
Apply the changes in the given alter table ops to the table given by name.
# File lib/sequel/database/schema_methods.rb 419 def apply_alter_table(name, ops) 420 alter_table_sql_list(name, ops).each{|sql| execute_ddl(sql)} 421 end
Apply the operations in the given generator to the table given by name.
# File lib/sequel/database/schema_methods.rb 424 def apply_alter_table_generator(name, generator) 425 ops = generator.operations 426 427 unless can_add_primary_key_constraint_on_nullable_columns? 428 if add_pk = ops.find{|op| op[:op] == :add_constraint && op[:type] == :primary_key} 429 ops = add_pk[:columns].map{|column| {:op => :set_column_null, :name => column, :null => false}} + ops 430 end 431 end 432 433 apply_alter_table(name, ops) 434 end
The SQL
string specify the autoincrement property, generally used by primary keys.
# File lib/sequel/database/schema_methods.rb 533 def auto_increment_sql 534 'AUTOINCREMENT' 535 end
Add null/not null SQL
fragment to column creation SQL
.
# File lib/sequel/database/schema_methods.rb 568 def column_definition_null_sql(sql, column) 569 null = column.fetch(:null, column[:allow_null]) 570 if null.nil? && !can_add_primary_key_constraint_on_nullable_columns? && column[:primary_key] 571 null = false 572 end 573 574 case null 575 when false 576 sql << ' NOT NULL' 577 when true 578 sql << ' NULL' 579 end 580 end
The order of the column definition, as an array of symbols.
# File lib/sequel/database/schema_methods.rb 538 def column_definition_order 539 COLUMN_DEFINITION_ORDER 540 end
Add primary key SQL
fragment to column creation SQL
.
# File lib/sequel/database/schema_methods.rb 583 def column_definition_primary_key_sql(sql, column) 584 if column[:primary_key] 585 if name = column[:primary_key_constraint_name] 586 sql << " CONSTRAINT #{quote_identifier(name)}" 587 end 588 sql << ' PRIMARY KEY' 589 constraint_deferrable_sql_append(sql, column[:primary_key_deferrable]) 590 end 591 end
Add foreign key reference SQL
fragment to column creation SQL
.
# File lib/sequel/database/schema_methods.rb 594 def column_definition_references_sql(sql, column) 595 if column[:table] 596 if name = column[:foreign_key_constraint_name] 597 sql << " CONSTRAINT #{quote_identifier(name)}" 598 end 599 sql << column_references_column_constraint_sql(column) 600 end 601 end
SQL
fragment containing the column creation SQL
for the given column.
# File lib/sequel/database/schema_methods.rb 543 def column_definition_sql(column) 544 sql = String.new 545 sql << "#{quote_identifier(column[:name])} #{type_literal(column)}" 546 column_definition_order.each{|m| send(:"column_definition_#{m}_sql", sql, column)} 547 sql 548 end
Add unique constraint SQL
fragment to column creation SQL
.
# File lib/sequel/database/schema_methods.rb 604 def column_definition_unique_sql(sql, column) 605 if column[:unique] 606 if name = column[:unique_constraint_name] 607 sql << " CONSTRAINT #{quote_identifier(name)}" 608 end 609 sql << ' UNIQUE' 610 constraint_deferrable_sql_append(sql, column[:unique_deferrable]) 611 end 612 end
SQL
for all given columns, used inside a CREATE TABLE block.
# File lib/sequel/database/schema_methods.rb 615 def column_list_sql(generator) 616 (generator.columns.map{|c| column_definition_sql(c)} + generator.constraints.map{|c| constraint_definition_sql(c)}).join(', ') 617 end
SQL
fragment for column foreign key references (column constraints)
# File lib/sequel/database/schema_methods.rb 620 def column_references_column_constraint_sql(column) 621 column_references_sql(column) 622 end
SQL
fragment for column foreign key references
# File lib/sequel/database/schema_methods.rb 625 def column_references_sql(column) 626 sql = String.new 627 sql << " REFERENCES #{quote_schema_table(column[:table])}" 628 sql << "(#{Array(column[:key]).map{|x| quote_identifier(x)}.join(', ')})" if column[:key] 629 sql << " ON DELETE #{on_delete_clause(column[:on_delete])}" if column[:on_delete] 630 sql << " ON UPDATE #{on_update_clause(column[:on_update])}" if column[:on_update] 631 constraint_deferrable_sql_append(sql, column[:deferrable]) 632 sql 633 end
SQL
fragment for table foreign key references (table constraints)
# File lib/sequel/database/schema_methods.rb 636 def column_references_table_constraint_sql(constraint) 637 "FOREIGN KEY #{literal(constraint[:columns])}#{column_references_sql(constraint)}" 638 end
Whether the given alter table operation is combinable.
# File lib/sequel/database/schema_methods.rb 641 def combinable_alter_table_op?(op) 642 COMBINABLE_ALTER_TABLE_OPS.include?(op[:op]) 643 end
SQL
fragment specifying the deferrable constraint attributes.
# File lib/sequel/database/schema_methods.rb 670 def constraint_deferrable_sql_append(sql, defer) 671 case defer 672 when nil 673 when false 674 sql << ' NOT DEFERRABLE' 675 when :immediate 676 sql << ' DEFERRABLE INITIALLY IMMEDIATE' 677 else 678 sql << ' DEFERRABLE INITIALLY DEFERRED' 679 end 680 end
SQL
fragment specifying a constraint on a table.
# File lib/sequel/database/schema_methods.rb 646 def constraint_definition_sql(constraint) 647 sql = String.new 648 sql << "CONSTRAINT #{quote_identifier(constraint[:name])} " if constraint[:name] 649 case constraint[:type] 650 when :check 651 check = constraint[:check] 652 check = check.first if check.is_a?(Array) && check.length == 1 653 check = filter_expr(check) 654 check = "(#{check})" unless check[0..0] == '(' && check[-1..-1] == ')' 655 sql << "CHECK #{check}" 656 when :primary_key 657 sql << "PRIMARY KEY #{literal(constraint[:columns])}" 658 when :foreign_key 659 sql << column_references_table_constraint_sql(constraint.merge(:deferrable=>nil)) 660 when :unique 661 sql << "UNIQUE #{literal(constraint[:columns])}" 662 else 663 raise Error, "Invalid constraint type #{constraint[:type]}, should be :check, :primary_key, :foreign_key, or :unique" 664 end 665 constraint_deferrable_sql_append(sql, constraint[:deferrable]) 666 sql 667 end
Run SQL
statement to create the table with the given name from the given SELECT sql statement.
# File lib/sequel/database/schema_methods.rb 740 def create_table_as(name, sql, options) 741 sql = sql.sql if sql.is_a?(Sequel::Dataset) 742 run(create_table_as_sql(name, sql, options)) 743 end
SQL
statement for creating a table from the result of a SELECT statement. sql
should be a string representing a SELECT query.
# File lib/sequel/database/schema_methods.rb 747 def create_table_as_sql(name, sql, options) 748 "#{create_table_prefix_sql(name, options)} AS #{sql}" 749 end
Execute the create table statements using the generator.
# File lib/sequel/database/schema_methods.rb 683 def create_table_from_generator(name, generator, options) 684 execute_ddl(create_table_sql(name, generator, options)) 685 end
The class used for create_table
generators.
# File lib/sequel/database/schema_methods.rb 688 def create_table_generator_class 689 Schema::CreateTableGenerator 690 end
Execute the create index statements using the generator.
# File lib/sequel/database/schema_methods.rb 693 def create_table_indexes_from_generator(name, generator, options) 694 e = options[:ignore_index_errors] || options[:if_not_exists] 695 generator.indexes.each do |index| 696 begin 697 pr = proc{index_sql_list(name, [index]).each{|sql| execute_ddl(sql)}} 698 supports_transactional_ddl? ? transaction(:savepoint=>:only, &pr) : pr.call 699 rescue Error 700 raise unless e 701 end 702 end 703 end
SQL
fragment for initial part of CREATE TABLE statement
# File lib/sequel/database/schema_methods.rb 752 def create_table_prefix_sql(name, options) 753 "CREATE #{temporary_table_sql if options[:temp]}TABLE#{' IF NOT EXISTS' if options[:if_not_exists]} #{options[:temp] ? quote_identifier(name) : quote_schema_table(name)}" 754 end
SQL
statement for creating a table with the given name, columns, and options
# File lib/sequel/database/schema_methods.rb 706 def create_table_sql(name, generator, options) 707 unless supports_named_column_constraints? 708 # Split column constraints into table constraints if they have a name 709 generator.columns.each do |c| 710 if (constraint_name = c.delete(:foreign_key_constraint_name)) && (table = c.delete(:table)) 711 opts = {} 712 opts[:name] = constraint_name 713 [:key, :on_delete, :on_update, :deferrable].each{|k| opts[k] = c[k]} 714 generator.foreign_key([c[:name]], table, opts) 715 end 716 if (constraint_name = c.delete(:unique_constraint_name)) && c.delete(:unique) 717 generator.unique(c[:name], :name=>constraint_name) 718 end 719 if (constraint_name = c.delete(:primary_key_constraint_name)) && c.delete(:primary_key) 720 generator.primary_key([c[:name]], :name=>constraint_name) 721 end 722 end 723 end 724 725 unless can_add_primary_key_constraint_on_nullable_columns? 726 if pk = generator.constraints.find{|op| op[:type] == :primary_key} 727 pk[:columns].each do |column| 728 if matched_column = generator.columns.find{|gc| gc[:name] == column} 729 matched_column[:null] = false 730 end 731 end 732 end 733 end 734 735 "#{create_table_prefix_sql(name, options)} (#{column_list_sql(generator)})" 736 end
SQL
fragment for initial part of CREATE VIEW statement
# File lib/sequel/database/schema_methods.rb 757 def create_view_prefix_sql(name, options) 758 create_view_sql_append_columns("CREATE #{'OR REPLACE 'if options[:replace]}VIEW #{quote_schema_table(name)}", options[:columns]) 759 end
SQL
statement for creating a view.
# File lib/sequel/database/schema_methods.rb 762 def create_view_sql(name, source, options) 763 source = source.sql if source.is_a?(Dataset) 764 sql = String.new 765 sql << "#{create_view_prefix_sql(name, options)} AS #{source}" 766 if check = options[:check] 767 sql << " WITH#{' LOCAL' if check == :local} CHECK OPTION" 768 end 769 sql 770 end
Append the column list to the SQL
, if a column list is given.
# File lib/sequel/database/schema_methods.rb 773 def create_view_sql_append_columns(sql, columns) 774 if columns 775 sql += ' (' 776 schema_utility_dataset.send(:identifier_list_append, sql, columns) 777 sql << ')' 778 end 779 sql 780 end
Default index name for the table and columns, may be too long for certain databases.
# File lib/sequel/database/schema_methods.rb 784 def default_index_name(table_name, columns) 785 schema, table = schema_and_table(table_name) 786 "#{"#{schema}_" if schema}#{table}_#{columns.map{|c| [String, Symbol].any?{|cl| c.is_a?(cl)} ? c : literal(c).gsub(/\W/, '_')}.join('_')}_index" 787 end
The SQL
to drop an index for the table.
# File lib/sequel/database/schema_methods.rb 797 def drop_index_sql(table, op) 798 "DROP INDEX #{quote_identifier(op[:name] || default_index_name(table, op[:columns]))}" 799 end
SQL
DDL statement to drop the table with the given name.
# File lib/sequel/database/schema_methods.rb 802 def drop_table_sql(name, options) 803 "DROP TABLE#{' IF EXISTS' if options[:if_exists]} #{quote_schema_table(name)}#{' CASCADE' if options[:cascade]}" 804 end
SQL
DDL statement to drop a view with the given name.
# File lib/sequel/database/schema_methods.rb 807 def drop_view_sql(name, options) 808 "DROP VIEW#{' IF EXISTS' if options[:if_exists]} #{quote_schema_table(name)}#{' CASCADE' if options[:cascade]}" 809 end
Proxy the filter_expr
call to the dataset, used for creating constraints. Support passing Proc arguments as blocks, as well as treating plain strings as literal strings, so that previous migrations that used this API do not break.
# File lib/sequel/database/schema_methods.rb 814 def filter_expr(*args, &block) 815 if args.length == 1 816 arg = args.first 817 if arg.is_a?(Proc) && !block 818 block = args.first 819 args = nil 820 elsif arg.is_a?(String) 821 args = [Sequel.lit(*args)] 822 elsif arg.is_a?(Array) 823 if arg.first.is_a?(String) 824 args = [Sequel.lit(*arg)] 825 elsif arg.length > 1 826 args = [Sequel.&(*arg)] 827 end 828 end 829 end 830 schema_utility_dataset.literal(schema_utility_dataset.send(:filter_expr, *args, &block)) 831 end
Get foreign key name for given table and columns.
# File lib/sequel/database/schema_methods.rb 790 def foreign_key_name(table_name, columns) 791 keys = foreign_key_list(table_name).select{|key| key[:columns] == columns} 792 raise(Error, "#{keys.empty? ? 'Missing' : 'Ambiguous'} foreign key for #{columns.inspect}") unless keys.size == 1 793 keys.first[:name] 794 end
SQL
statement for creating an index for the table with the given name and index specifications.
# File lib/sequel/database/schema_methods.rb 835 def index_definition_sql(table_name, index) 836 index_name = index[:name] || default_index_name(table_name, index[:columns]) 837 raise Error, "Index types are not supported for this database" if index[:type] 838 raise Error, "Partial indexes are not supported for this database" if index[:where] && !supports_partial_indexes? 839 "CREATE #{'UNIQUE ' if index[:unique]}INDEX #{quote_identifier(index_name)} ON #{quote_schema_table(table_name)} #{literal(index[:columns])}#{" WHERE #{filter_expr(index[:where])}" if index[:where]}" 840 end
Extract the join table name from the arguments given to create_join_table. Also does argument validation for the create_join_table
method.
# File lib/sequel/database/schema_methods.rb 850 def join_table_name(hash, options) 851 entries = hash.values 852 raise Error, "must have 2 entries in hash given to (create|drop)_join_table" unless entries.length == 2 853 if options[:name] 854 options[:name] 855 else 856 table_names = entries.map{|e| join_table_name_extract(e)} 857 table_names.map(&:to_s).sort.join('_') 858 end 859 end
Extract an individual join table name, which should either be a string or symbol, or a hash containing one of those as the value for :table.
# File lib/sequel/database/schema_methods.rb 863 def join_table_name_extract(entry) 864 case entry 865 when Symbol, String 866 entry 867 when Hash 868 join_table_name_extract(entry[:table]) 869 else 870 raise Error, "can't extract table name from #{entry.inspect}" 871 end 872 end
SQL
fragment to use for ON DELETE, based on the given action. The following actions are recognized:
- :cascade
-
Delete rows referencing this row.
- :no_action
-
Raise an error if other rows reference this row, allow deferring of the integrity check. This is the default.
- :restrict
-
Raise an error if other rows reference this row, but do not allow deferring the integrity check.
- :set_default
-
Set columns referencing this row to their default value.
- :set_null
-
Set columns referencing this row to NULL.
Any other object given is just converted to a string, with “_” converted to “ ” and upcased.
# File lib/sequel/database/schema_methods.rb 887 def on_delete_clause(action) 888 action.to_s.gsub("_", " ").upcase 889 end
Alias of on_delete_clause
, since the two usually behave the same.
# File lib/sequel/database/schema_methods.rb 892 def on_update_clause(action) 893 on_delete_clause(action) 894 end
Proxy the quote_schema_table
method to the dataset
# File lib/sequel/database/schema_methods.rb 897 def quote_schema_table(table) 898 schema_utility_dataset.quote_schema_table(table) 899 end
SQL
statement for renaming a table.
# File lib/sequel/database/schema_methods.rb 902 def rename_table_sql(name, new_name) 903 "ALTER TABLE #{quote_schema_table(name)} RENAME TO #{quote_schema_table(new_name)}" 904 end
Split the schema information from the table
# File lib/sequel/database/schema_methods.rb 907 def schema_and_table(table_name) 908 schema_utility_dataset.schema_and_table(table_name) 909 end
Return true if the given column schema represents an autoincrementing primary key.
# File lib/sequel/database/schema_methods.rb 912 def schema_autoincrementing_primary_key?(schema) 913 !!(schema[:primary_key] && schema[:auto_increment]) 914 end
The dataset to use for proxying certain schema methods.
# File lib/sequel/database/schema_methods.rb 917 def schema_utility_dataset 918 @default_dataset 919 end
Split the schema information from the table
# File lib/sequel/database/schema_methods.rb 922 def split_qualifiers(table_name) 923 schema_utility_dataset.split_qualifiers(table_name) 924 end
SQL
fragment for temporary table
# File lib/sequel/database/schema_methods.rb 927 def temporary_table_sql 928 'TEMPORARY ' 929 end
SQL
fragment specifying the type of a given column.
# File lib/sequel/database/schema_methods.rb 932 def type_literal(column) 933 case column[:type] 934 when Class 935 type_literal_generic(column) 936 when :Bignum 937 type_literal_generic_bignum_symbol(column) 938 else 939 type_literal_specific(column) 940 end 941 end
SQL
fragment specifying the full type of a column, consider the type with possible modifiers.
# File lib/sequel/database/schema_methods.rb 945 def type_literal_generic(column) 946 meth = "type_literal_generic_#{column[:type].name.to_s.downcase}" 947 if respond_to?(meth, true) 948 # Allow calling private methods as per type literal generic methods are private 949 send(meth, column) 950 else 951 raise Error, "Unsupported ruby class used as database type: #{column[:type]}" 952 end 953 end
Alias for type_literal_generic_numeric
, to make overriding in a subclass easier.
# File lib/sequel/database/schema_methods.rb 956 def type_literal_generic_bigdecimal(column) 957 type_literal_generic_numeric(column) 958 end
Sequel
uses the bigint type by default for :Bignum symbol.
# File lib/sequel/database/schema_methods.rb 961 def type_literal_generic_bignum_symbol(column) 962 :bigint 963 end
Sequel
uses the date type by default for Dates.
# File lib/sequel/database/schema_methods.rb 966 def type_literal_generic_date(column) 967 :date 968 end
Sequel
uses the timestamp type by default for DateTimes.
# File lib/sequel/database/schema_methods.rb 971 def type_literal_generic_datetime(column) 972 :timestamp 973 end
Alias for type_literal_generic_trueclass
, to make overriding in a subclass easier.
# File lib/sequel/database/schema_methods.rb 976 def type_literal_generic_falseclass(column) 977 type_literal_generic_trueclass(column) 978 end
Sequel
uses the blob type by default for Files.
# File lib/sequel/database/schema_methods.rb 981 def type_literal_generic_file(column) 982 :blob 983 end
Alias for type_literal_generic_integer
, to make overriding in a subclass easier.
# File lib/sequel/database/schema_methods.rb 986 def type_literal_generic_fixnum(column) 987 type_literal_generic_integer(column) 988 end
Sequel
uses the double precision type by default for Floats.
# File lib/sequel/database/schema_methods.rb 991 def type_literal_generic_float(column) 992 :"double precision" 993 end
Sequel
uses the integer type by default for integers
# File lib/sequel/database/schema_methods.rb 996 def type_literal_generic_integer(column) 997 :integer 998 end
Sequel
uses the numeric type by default for Numerics and BigDecimals. If a size is given, it is used, otherwise, it will default to whatever the database default is for an unsized value.
# File lib/sequel/database/schema_methods.rb 1003 def type_literal_generic_numeric(column) 1004 column[:size] ? "numeric(#{Array(column[:size]).join(', ')})" : :numeric 1005 end
Use time by default for Time values if :only_time option is used.
# File lib/sequel/database/schema_methods.rb 1032 def type_literal_generic_only_time(column) 1033 :time 1034 end
Sequel
uses the varchar type by default for Strings. If a size isn't present, Sequel
assumes a size of 255. If the :fixed option is used, Sequel
uses the char type. If the :text option is used, Sequel
uses the :text type.
# File lib/sequel/database/schema_methods.rb 1011 def type_literal_generic_string(column) 1012 if column[:text] 1013 uses_clob_for_text? ? :clob : :text 1014 elsif column[:fixed] 1015 "char(#{column[:size]||default_string_column_size})" 1016 else 1017 "varchar(#{column[:size]||default_string_column_size})" 1018 end 1019 end
Sequel
uses the timestamp type by default for Time values. If the :only_time option is used, the time type is used.
# File lib/sequel/database/schema_methods.rb 1023 def type_literal_generic_time(column) 1024 if column[:only_time] 1025 type_literal_generic_only_time(column) 1026 else 1027 type_literal_generic_datetime(column) 1028 end 1029 end
Sequel
uses the boolean type by default for TrueClass
and FalseClass
.
# File lib/sequel/database/schema_methods.rb 1037 def type_literal_generic_trueclass(column) 1038 :boolean 1039 end
SQL
fragment for the given type of a column if the column is not one of the generic types specified with a ruby class.
# File lib/sequel/database/schema_methods.rb 1043 def type_literal_specific(column) 1044 type = column[:type] 1045 type = "double precision" if type.to_s == 'double' 1046 column[:size] ||= default_string_column_size if type.to_s == 'varchar' 1047 elements = column[:size] || column[:elements] 1048 "#{type}#{literal(Array(elements)) if elements}#{' UNSIGNED' if column[:unsigned]}" 1049 end
Whether clob should be used for String
text: true columns.
# File lib/sequel/database/schema_methods.rb 1052 def uses_clob_for_text? 1053 false 1054 end
3 - Methods that create datasets
↑ topPublic Instance Methods
Returns a dataset for the database. If the first argument is a string, the method acts as an alias for Database#fetch
, returning a dataset for arbitrary SQL
, with or without placeholders:
DB['SELECT * FROM items'].all DB['SELECT * FROM items WHERE name = ?', my_name].all
Otherwise, acts as an alias for Database#from
, setting the primary table for the dataset:
DB[:items].sql #=> "SELECT * FROM items"
# File lib/sequel/database/dataset.rb 21 def [](*args) 22 args.first.is_a?(String) ? fetch(*args) : from(*args) 23 end
Returns a blank dataset for this database.
DB.dataset # SELECT * DB.dataset.from(:items) # SELECT * FROM items
# File lib/sequel/database/dataset.rb 29 def dataset 30 @dataset_class.new(self) 31 end
Fetches records for an arbitrary SQL
statement. If a block is given, it is used to iterate over the records:
DB.fetch('SELECT * FROM items'){|r| p r}
The fetch
method returns a dataset instance:
DB.fetch('SELECT * FROM items').all
fetch
can also perform parameterized queries for protection against SQL
injection:
DB.fetch('SELECT * FROM items WHERE name = ?', my_name).all
See caveats listed in Dataset#with_sql
regarding datasets using custom SQL
and the methods that can be called on them.
# File lib/sequel/database/dataset.rb 49 def fetch(sql, *args, &block) 50 ds = @default_dataset.with_sql(sql, *args) 51 ds.each(&block) if block 52 ds 53 end
Returns a new dataset with the from
method invoked. If a block is given, it acts as a virtual row block
DB.from(:items) # SELECT * FROM items DB.from{schema[:table]} # SELECT * FROM schema.table
# File lib/sequel/database/dataset.rb 60 def from(*args, &block) 61 if block 62 @default_dataset.from(*args, &block) 63 elsif args.length == 1 && (table = args[0]).is_a?(Symbol) 64 @default_dataset.send(:cached_dataset, :"_from_#{table}_ds"){@default_dataset.from(table)} 65 else 66 @default_dataset.from(*args) 67 end 68 end
Returns a new dataset with the select method invoked.
DB.select(1) # SELECT 1 DB.select{server_version.function} # SELECT server_version() DB.select(:id).from(:items) # SELECT id FROM items
# File lib/sequel/database/dataset.rb 75 def select(*args, &block) 76 @default_dataset.select(*args, &block) 77 end
4 - Methods relating to adapters, connecting, disconnecting, and sharding
↑ topConstants
- ADAPTERS
Array
of supported database adapters
Attributes
Public Class Methods
The Database
subclass for the given adapter scheme. Raises Sequel::AdapterNotFound if the adapter could not be loaded.
# File lib/sequel/database/connecting.rb 16 def self.adapter_class(scheme) 17 scheme.is_a?(Class) ? scheme : load_adapter(scheme.to_sym) 18 end
Returns the scheme symbol for the Database
class.
# File lib/sequel/database/connecting.rb 21 def self.adapter_scheme 22 @scheme 23 end
Connects to a database. See Sequel.connect
.
# File lib/sequel/database/connecting.rb 26 def self.connect(conn_string, opts = OPTS) 27 case conn_string 28 when String 29 if conn_string.start_with?('jdbc:') 30 c = adapter_class(:jdbc) 31 opts = opts.merge(:orig_opts=>opts.dup) 32 opts = {:uri=>conn_string}.merge!(opts) 33 else 34 uri = URI.parse(conn_string) 35 scheme = uri.scheme 36 c = adapter_class(scheme) 37 uri_options = c.send(:uri_to_options, uri) 38 uri.query.split('&').map{|s| s.split('=')}.each{|k,v| uri_options[k.to_sym] = v if k && !k.empty?} unless uri.query.to_s.strip.empty? 39 uri_options.to_a.each{|k,v| uri_options[k] = (defined?(URI::DEFAULT_PARSER) ? URI::DEFAULT_PARSER : URI).unescape(v) if v.is_a?(String)} 40 opts = uri_options.merge(opts).merge!(:orig_opts=>opts.dup, :uri=>conn_string, :adapter=>scheme) 41 end 42 when Hash 43 opts = conn_string.merge(opts) 44 opts = opts.merge(:orig_opts=>opts.dup) 45 c = adapter_class(opts[:adapter_class] || opts[:adapter] || opts['adapter']) 46 else 47 raise Error, "Sequel::Database.connect takes either a Hash or a String, given: #{conn_string.inspect}" 48 end 49 50 opts = opts.inject({}) do |m, (k,v)| 51 k = :user if k.to_s == 'username' 52 m[k.to_sym] = v 53 m 54 end 55 56 begin 57 db = c.new(opts) 58 db.test_connection if db.send(:typecast_value_boolean, opts.fetch(:test, true)) 59 if block_given? 60 return yield(db) 61 end 62 ensure 63 if block_given? 64 db.disconnect if db 65 Sequel.synchronize{::Sequel::DATABASES.delete(db)} 66 end 67 end 68 db 69 end
Load the adapter from the file system. Raises Sequel::AdapterNotFound if the adapter cannot be loaded, or if the adapter isn't registered correctly after being loaded. Options:
- :map
-
The
Hash
in which to look for an already loaded adapter (defaults to ADAPTER_MAP). - :subdir
-
The subdirectory of sequel/adapters to look in, only to be used for loading subadapters.
# File lib/sequel/database/connecting.rb 77 def self.load_adapter(scheme, opts=OPTS) 78 map = opts[:map] || ADAPTER_MAP 79 if subdir = opts[:subdir] 80 file = "#{subdir}/#{scheme}" 81 else 82 file = scheme 83 end 84 85 unless obj = Sequel.synchronize{map[scheme]} 86 # attempt to load the adapter file 87 begin 88 require "sequel/adapters/#{file}" 89 rescue LoadError => e 90 # If subadapter file doesn't exist, just return, 91 # using the main adapter class without database customizations. 92 return if subdir 93 raise Sequel.convert_exception_class(e, AdapterNotFound) 94 end 95 96 # make sure we actually loaded the adapter 97 unless obj = Sequel.synchronize{map[scheme]} 98 raise AdapterNotFound, "Could not load #{file} adapter: adapter class not registered in ADAPTER_MAP" 99 end 100 end 101 102 obj 103 end
Public Instance Methods
Returns the scheme symbol for this instance's class, which reflects which adapter is being used. In some cases, this can be the same as the database_type
(for native adapters), in others (i.e. adapters with subadapters), it will be different.
Sequel.connect('jdbc:postgres://...').adapter_scheme # => :jdbc
# File lib/sequel/database/connecting.rb 162 def adapter_scheme 163 self.class.adapter_scheme 164 end
Dynamically add new servers or modify server options at runtime. Also adds new servers to the connection pool. Only usable when using a sharded connection pool.
servers argument should be a hash with server name symbol keys and hash or proc values. If a servers key is already in use, it's value is overridden with the value provided.
DB.add_servers(f: {host: "hash_host_f"})
# File lib/sequel/database/connecting.rb 174 def add_servers(servers) 175 unless sharded? 176 raise Error, "cannot call Database#add_servers on a Database instance that does not use a sharded connection pool" 177 end 178 179 h = @opts[:servers] 180 Sequel.synchronize{h.merge!(servers)} 181 @pool.add_servers(servers.keys) 182 end
The database type for this database object, the same as the adapter scheme by default. Should be overridden in adapters (especially shared adapters) to be the correct type, so that even if two separate Database
objects are using different adapters you can tell that they are using the same database type. Even better, you can tell that two Database
objects that are using the same adapter are connecting to different database types.
Sequel.connect('jdbc:postgres://...').database_type # => :postgres
# File lib/sequel/database/connecting.rb 193 def database_type 194 adapter_scheme 195 end
Disconnects all available connections from the connection pool. Any connections currently in use will not be disconnected. Options:
- :server
-
Should be a symbol specifing the server to disconnect from,
or an array of symbols to specify multiple servers.
Example:
DB.disconnect # All servers DB.disconnect(server: :server1) # Single server DB.disconnect(server: [:server1, :server2]) # Multiple servers
# File lib/sequel/database/connecting.rb 207 def disconnect(opts = OPTS) 208 pool.disconnect(opts) 209 end
Should only be called by the connection pool code to disconnect a connection. By default, calls the close method on the connection object, since most adapters use that, but should be overwritten on other adapters.
# File lib/sequel/database/connecting.rb 214 def disconnect_connection(conn) 215 conn.close 216 end
Dynamically remove existing servers from the connection pool. Only usable when using a sharded connection pool
servers should be symbols or arrays of symbols. If a nonexistent server is specified, it is ignored. If no servers have been specified for this database, no changes are made. If you attempt to remove the :default server, an error will be raised.
DB.remove_servers(:f1, :f2)
# File lib/sequel/database/connecting.rb 227 def remove_servers(*servers) 228 unless sharded? 229 raise Error, "cannot call Database#remove_servers on a Database instance that does not use a sharded connection pool" 230 end 231 232 h = @opts[:servers] 233 servers.flatten.each{|s| Sequel.synchronize{h.delete(s)}} 234 @pool.remove_servers(servers) 235 end
An array of servers/shards for this Database
object.
DB.servers # Unsharded: => [:default] DB.servers # Sharded: => [:default, :server1, :server2]
# File lib/sequel/database/connecting.rb 241 def servers 242 pool.servers 243 end
Returns true if the database is using a single-threaded connection pool.
# File lib/sequel/database/connecting.rb 246 def single_threaded? 247 @single_threaded 248 end
:nocov:
# File lib/sequel/database/connecting.rb 252 def synchronize(server=nil) 253 @pool.hold(server || :default){|conn| yield conn} 254 end
Attempts to acquire a database connection. Returns true if successful. Will probably raise an Error
if unsuccessful. If a server argument is given, attempts to acquire a database connection to the given server/shard.
# File lib/sequel/database/connecting.rb 278 def test_connection(server=nil) 279 synchronize(server){|conn|} 280 true 281 end
Check whether the given connection is currently valid, by running a query against it. If the query fails, the connection should probably be removed from the connection pool.
# File lib/sequel/database/connecting.rb 287 def valid_connection?(conn) 288 sql = valid_connection_sql 289 begin 290 log_connection_execute(conn, sql) 291 rescue Sequel::DatabaseError, *database_error_classes 292 false 293 else 294 true 295 end 296 end
Private Instance Methods
The default options for the connection pool.
# File lib/sequel/database/connecting.rb 301 def connection_pool_default_options 302 {} 303 end
Return the options for the given server by merging the generic options for all server with the specific options for the given server specified in the :servers option.
# File lib/sequel/database/connecting.rb 308 def server_opts(server) 309 opts = if @opts[:servers] and server_options = @opts[:servers][server] 310 case server_options 311 when Hash 312 @opts.merge(server_options) 313 when Proc 314 @opts.merge(server_options.call(self)) 315 else 316 raise Error, 'Server opts should be a hash or proc' 317 end 318 elsif server.is_a?(Hash) 319 @opts.merge(server) 320 else 321 @opts.dup 322 end 323 opts.delete(:servers) 324 opts 325 end
The SQL
query to issue to check if a connection is valid.
# File lib/sequel/database/connecting.rb 328 def valid_connection_sql 329 @valid_connection_sql ||= select(nil).sql 330 end
5 - Methods that set defaults for created datasets
↑ topAttributes
The class to use for creating datasets. Should respond to new with the Database
argument as the first argument, and an optional options hash.
Public Instance Methods
If the database has any dataset modules associated with it, use a subclass of the given class that includes the modules as the dataset class.
# File lib/sequel/database/dataset_defaults.rb 18 def dataset_class=(c) 19 unless @dataset_modules.empty? 20 c = Class.new(c) 21 @dataset_modules.each{|m| c.send(:include, m)} 22 end 23 @dataset_class = c 24 reset_default_dataset 25 end
Equivalent to extending all datasets produced by the database with a module. What it actually does is use a subclass of the current dataset_class
as the new dataset_class
, and include the module in the subclass. Instead of a module, you can provide a block that is used to create an anonymous module.
This allows you to override any of the dataset methods even if they are defined directly on the dataset class that this Database
object uses.
If a block is given, a Dataset::DatasetModule
instance is created, allowing for the easy creation of named dataset methods that will do caching.
Examples:
# Introspect columns for all of DB's datasets DB.extend_datasets(Sequel::ColumnsIntrospection) # Trace all SELECT queries by printing the SQL and the full backtrace DB.extend_datasets do def fetch_rows(sql) puts sql puts caller super end end # Add some named dataset methods DB.extend_datasets do order :by_id, :id select :with_id_and_name, :id, :name where :active, :active end DB[:table].active.with_id_and_name.by_id # SELECT id, name FROM table WHERE active ORDER BY id
# File lib/sequel/database/dataset_defaults.rb 62 def extend_datasets(mod=nil, &block) 63 raise(Error, "must provide either mod or block, not both") if mod && block 64 mod = Dataset::DatasetModule.new(&block) if block 65 if @dataset_modules.empty? 66 @dataset_modules = [mod] 67 @dataset_class = Class.new(@dataset_class) 68 else 69 @dataset_modules << mod 70 end 71 @dataset_class.send(:include, mod) 72 reset_default_dataset 73 end
Private Instance Methods
The default dataset class to use for the database
# File lib/sequel/database/dataset_defaults.rb 78 def dataset_class_default 79 Sequel::Dataset 80 end
Whether to quote identifiers by default for this database, true by default.
# File lib/sequel/database/dataset_defaults.rb 89 def quote_identifiers_default 90 true 91 end
Reset the default dataset used by most Database
methods that create datasets.
# File lib/sequel/database/dataset_defaults.rb 83 def reset_default_dataset 84 Sequel.synchronize{@symbol_literal_cache.clear} 85 @default_dataset = dataset 86 end
6 - Methods relating to logging
↑ topAttributes
Whether to include information about the connection in use when logging queries.
Numeric
specifying the duration beyond which queries are logged at warn level instead of info level.
Log level at which to log SQL
queries. This is actually the method sent to the logger, so it should be the method name symbol. The default is :info, it can be set to :debug to log at DEBUG level.
Public Instance Methods
Yield to the block, logging any errors at error level to all loggers, and all other queries with the duration at warn or info level.
# File lib/sequel/database/logging.rb 37 def log_connection_yield(sql, conn, args=nil) 38 return yield if skip_logging? 39 sql = "#{connection_info(conn) if conn && log_connection_info}#{sql}#{"; #{args.inspect}" if args}" 40 timer = Sequel.start_timer 41 42 begin 43 yield 44 rescue => e 45 log_exception(e, sql) 46 raise 47 ensure 48 log_duration(Sequel.elapsed_seconds_since(timer), sql) unless e 49 end 50 end
Log a message at error level, with information about the exception.
# File lib/sequel/database/logging.rb 26 def log_exception(exception, message) 27 log_each(:error, "#{exception.class}: #{exception.message.strip if exception.message}: #{message}") 28 end
Log a message at level info to all loggers.
# File lib/sequel/database/logging.rb 31 def log_info(message, args=nil) 32 log_each(:info, args ? "#{message}; #{args.inspect}" : message) 33 end
Remove any existing loggers and just use the given logger:
DB.logger = Logger.new($stdout)
# File lib/sequel/database/logging.rb 55 def logger=(logger) 56 @loggers = Array(logger) 57 end
Private Instance Methods
String
including information about the connection, for use when logging connection info.
# File lib/sequel/database/logging.rb 69 def connection_info(conn) 70 "(conn: #{conn.__id__}) " 71 end
Log the given SQL
and then execute it on the connection, used by the transaction code.
# File lib/sequel/database/logging.rb 75 def log_connection_execute(conn, sql) 76 log_connection_yield(sql, conn){conn.public_send(connection_execute_method, sql)} 77 end
Log message with message prefixed by duration at info level, or warn level if duration is greater than log_warn_duration.
# File lib/sequel/database/logging.rb 81 def log_duration(duration, message) 82 log_each((lwd = log_warn_duration and duration >= lwd) ? :warn : sql_log_level, "(#{sprintf('%0.6fs', duration)}) #{message}") 83 end
Log message at level (which should be :error, :warn, or :info) to all loggers.
# File lib/sequel/database/logging.rb 87 def log_each(level, message) 88 @loggers.each{|logger| logger.public_send(level, message)} 89 end
Determine if logging should be skipped. Defaults to true if no loggers have been specified.
# File lib/sequel/database/logging.rb 63 def skip_logging? 64 @loggers.empty? 65 end
7 - Miscellaneous methods
↑ topConstants
- CHECK_CONSTRAINT_SQLSTATES
- DEFAULT_DATABASE_ERROR_REGEXPS
Empty exception regexp to class map, used by default if
Sequel
doesn't have specific support for the database in use.- DEFAULT_STRING_COLUMN_SIZE
The general default size for string columns for all
Sequel::Database
instances.- EXTENSIONS
Hash
of extension name symbols to callable objects to load the extension into theDatabase
object (usually by extending it with a module defined in the extension).- FOREIGN_KEY_CONSTRAINT_SQLSTATES
- NOT_NULL_CONSTRAINT_SQLSTATES
- SCHEMA_TYPE_CLASSES
Mapping of schema type symbols to class or arrays of classes for that symbol.
- SERIALIZATION_CONSTRAINT_SQLSTATES
- UNIQUE_CONSTRAINT_SQLSTATES
Attributes
The specific default size of string columns for this Sequel::Database
, usually 255 by default.
The options hash for this database
Set the timezone to use for this database, overridding Sequel.database_timezone
.
Public Class Methods
Register a hook that will be run when a new Database
is instantiated. It is called with the new database handle.
# File lib/sequel/database/misc.rb 34 def self.after_initialize(&block) 35 raise Error, "must provide block to after_initialize" unless block 36 Sequel.synchronize do 37 previous = @initialize_hook 38 @initialize_hook = proc do |db| 39 previous.call(db) 40 block.call(db) 41 end 42 end 43 end
Apply an extension to all Database
objects created in the future.
# File lib/sequel/database/misc.rb 46 def self.extension(*extensions) 47 after_initialize{|db| db.extension(*extensions)} 48 end
Constructs a new instance of a database connection with the specified options hash.
Accepts the following options:
- :cache_schema
-
Whether schema should be cached for this
Database
instance - :default_string_column_size
-
The default size of string columns, 255 by default.
- :extensions
-
Extensions to load into this
Database
instance. Can be a symbol, array of symbols, or string with extensions separated by columns. These extensions are loaded after connections are made by the :preconnect option. - :keep_reference
-
Whether to keep a reference to this instance in Sequel::DATABASES, true by default.
- :logger
-
A specific logger to use.
- :loggers
-
An array of loggers to use.
- :log_connection_info
-
Whether connection information should be logged when logging queries.
- :log_warn_duration
-
The number of elapsed seconds after which queries should be logged at warn level.
- :name
-
A name to use for the
Database
object, displayed in PoolTimeout . - :preconnect
-
Automatically create the maximum number of connections, so that they don't need to be created as needed. This is useful when connecting takes a long time and you want to avoid possible latency during runtime. Set to :concurrently to create the connections in separate threads. Otherwise they'll be created sequentially.
- :preconnect_extensions
-
Similar to the :extensions option, but loads the extensions before the connections are made by the :preconnect option.
- :quote_identifiers
-
Whether to quote identifiers.
- :servers
-
A hash specifying a server/shard specific options, keyed by shard symbol .
- :single_threaded
-
Whether to use a single-threaded connection pool.
- :sql_log_level
-
Method to use to log
SQL
to a logger, :info by default.
All options given are also passed to the connection pool. Additional options respected by the connection pool are :after_connect, :connect_sqls, :max_connections, :pool_timeout, :servers, and :servers_hash. See the connection pool documentation for details.
# File lib/sequel/database/misc.rb 124 def initialize(opts = OPTS) 125 @opts ||= opts 126 @opts = connection_pool_default_options.merge(@opts) 127 @loggers = Array(@opts[:logger]) + Array(@opts[:loggers]) 128 @opts[:servers] = {} if @opts[:servers].is_a?(String) 129 @sharded = !!@opts[:servers] 130 @opts[:adapter_class] = self.class 131 @opts[:single_threaded] = @single_threaded = typecast_value_boolean(@opts.fetch(:single_threaded, Sequel.single_threaded)) 132 @default_string_column_size = @opts[:default_string_column_size] || DEFAULT_STRING_COLUMN_SIZE 133 134 @schemas = {} 135 @prepared_statements = {} 136 @transactions = {} 137 @symbol_literal_cache = {} 138 139 @timezone = nil 140 141 @dataset_class = dataset_class_default 142 @cache_schema = typecast_value_boolean(@opts.fetch(:cache_schema, true)) 143 @dataset_modules = [] 144 @loaded_extensions = [] 145 @schema_type_classes = SCHEMA_TYPE_CLASSES.dup 146 147 self.sql_log_level = @opts[:sql_log_level] ? @opts[:sql_log_level].to_sym : :info 148 self.log_warn_duration = @opts[:log_warn_duration] 149 self.log_connection_info = typecast_value_boolean(@opts[:log_connection_info]) 150 151 @pool = ConnectionPool.get_pool(self, @opts) 152 153 reset_default_dataset 154 adapter_initialize 155 156 unless typecast_value_boolean(@opts[:keep_reference]) == false 157 Sequel.synchronize{::Sequel::DATABASES.push(self)} 158 end 159 Sequel::Database.run_after_initialize(self) 160 161 initialize_load_extensions(:preconnect_extensions) 162 163 if typecast_value_boolean(@opts[:preconnect]) && @pool.respond_to?(:preconnect, true) 164 concurrent = typecast_value_string(@opts[:preconnect]) == "concurrently" 165 @pool.send(:preconnect, concurrent) 166 end 167 168 initialize_load_extensions(:extensions) 169 end
Register an extension callback for Database
objects. ext should be the extension name symbol, and mod should either be a Module that the database is extended with, or a callable object called with the database object. If mod is not provided, a block can be provided and is treated as the mod object.
# File lib/sequel/database/misc.rb 55 def self.register_extension(ext, mod=nil, &block) 56 if mod 57 raise(Error, "cannot provide both mod and block to Database.register_extension") if block 58 if mod.is_a?(Module) 59 block = proc{|db| db.extend(mod)} 60 else 61 block = mod 62 end 63 end 64 Sequel.synchronize{EXTENSIONS[ext] = block} 65 end
Run the after_initialize
hook for the given instance
.
# File lib/sequel/database/misc.rb 68 def self.run_after_initialize(instance) 69 @initialize_hook.call(instance) 70 end
Private Class Methods
Converts a uri to an options hash. These options are then passed to a newly created database object.
# File lib/sequel/database/misc.rb 74 def self.uri_to_options(uri) 75 { 76 :user => uri.user, 77 :password => uri.password, 78 :port => uri.port, 79 :host => uri.hostname, 80 :database => (m = /\/(.*)/.match(uri.path)) && (m[1]) 81 } 82 end
Public Instance Methods
Cast the given type to a literal type
DB.cast_type_literal(Float) # double precision DB.cast_type_literal(:foo) # foo
# File lib/sequel/database/misc.rb 196 def cast_type_literal(type) 197 type_literal(:type=>type) 198 end
Load an extension into the receiver. In addition to requiring the extension file, this also modifies the database to work with the extension (usually extending it with a module defined in the extension file). If no related extension file exists or the extension does not have specific support for Database
objects, an Error
will be raised. Returns self.
# File lib/sequel/database/misc.rb 205 def extension(*exts) 206 Sequel.extension(*exts) 207 exts.each do |ext| 208 if pr = Sequel.synchronize{EXTENSIONS[ext]} 209 unless Sequel.synchronize{@loaded_extensions.include?(ext)} 210 Sequel.synchronize{@loaded_extensions << ext} 211 pr.call(self) 212 end 213 else 214 raise(Error, "Extension #{ext} does not have specific support handling individual databases (try: Sequel.extension #{ext.inspect})") 215 end 216 end 217 self 218 end
Freeze internal data structures for the Database
instance.
# File lib/sequel/database/misc.rb 172 def freeze 173 valid_connection_sql 174 metadata_dataset 175 @opts.freeze 176 @loggers.freeze 177 @pool.freeze 178 @dataset_class.freeze 179 @dataset_modules.freeze 180 @schema_type_classes.freeze 181 @loaded_extensions.freeze 182 metadata_dataset 183 super 184 end
Convert the given timestamp from the application's timezone, to the databases's timezone or the default database timezone if the database does not have a timezone.
# File lib/sequel/database/misc.rb 223 def from_application_timestamp(v) 224 Sequel.convert_output_timestamp(v, timezone) 225 end
Returns a string representation of the database object including the class name and connection URI and options used when connecting (if any).
# File lib/sequel/database/misc.rb 229 def inspect 230 a = [] 231 a << uri.inspect if uri 232 if (oo = opts[:orig_opts]) && !oo.empty? 233 a << oo.inspect 234 end 235 "#<#{self.class}: #{a.join(' ')}>" 236 end
Proxy the literal call to the dataset.
DB.literal(1) # 1 DB.literal(:a) # a DB.literal('a') # 'a'
# File lib/sequel/database/misc.rb 243 def literal(v) 244 schema_utility_dataset.literal(v) 245 end
Return the literalized version of the symbol if cached, or nil if it is not cached.
# File lib/sequel/database/misc.rb 249 def literal_symbol(sym) 250 Sequel.synchronize{@symbol_literal_cache[sym]} 251 end
Set the cached value of the literal symbol.
# File lib/sequel/database/misc.rb 254 def literal_symbol_set(sym, lit) 255 Sequel.synchronize{@symbol_literal_cache[sym] = lit} 256 end
Synchronize access to the prepared statements cache.
# File lib/sequel/database/misc.rb 259 def prepared_statement(name) 260 Sequel.synchronize{prepared_statements[name]} 261 end
Proxy the quote_identifier
method to the dataset, useful for quoting unqualified identifiers for use outside of datasets.
# File lib/sequel/database/misc.rb 266 def quote_identifier(v) 267 schema_utility_dataset.quote_identifier(v) 268 end
Return ruby class or array of classes for the given type symbol.
# File lib/sequel/database/misc.rb 271 def schema_type_class(type) 272 @schema_type_classes[type] 273 end
Default serial primary key options, used by the table creation code.
# File lib/sequel/database/misc.rb 276 def serial_primary_key_options 277 {:primary_key => true, :type => Integer, :auto_increment => true} 278 end
Cache the prepared statement object at the given name.
# File lib/sequel/database/misc.rb 281 def set_prepared_statement(name, ps) 282 Sequel.synchronize{prepared_statements[name] = ps} 283 end
Whether this database instance uses multiple servers, either for sharding or for primary/replica configurations.
# File lib/sequel/database/misc.rb 287 def sharded? 288 @sharded 289 end
The timezone to use for this database, defaulting to Sequel.database_timezone
.
# File lib/sequel/database/misc.rb 292 def timezone 293 @timezone || Sequel.database_timezone 294 end
Convert the given timestamp to the application's timezone, from the databases's timezone or the default database timezone if the database does not have a timezone.
# File lib/sequel/database/misc.rb 299 def to_application_timestamp(v) 300 Sequel.convert_timestamp(v, timezone) 301 end
Typecast the value to the given column_type. Calls typecast_value_#{column_type} if the method exists, otherwise returns the value. This method should raise Sequel::InvalidValue if assigned value is invalid.
# File lib/sequel/database/misc.rb 308 def typecast_value(column_type, value) 309 return nil if value.nil? 310 meth = "typecast_value_#{column_type}" 311 begin 312 # Allow calling private methods as per-type typecasting methods are private 313 respond_to?(meth, true) ? send(meth, value) : value 314 rescue ArgumentError, TypeError => e 315 raise Sequel.convert_exception_class(e, InvalidValue) 316 end 317 end
Returns the URI use to connect to the database. If a URI was not used when connecting, returns nil.
# File lib/sequel/database/misc.rb 321 def uri 322 opts[:uri] 323 end
Explicit alias of uri for easier subclassing.
# File lib/sequel/database/misc.rb 326 def url 327 uri 328 end
Private Instance Methods
:nocov:
# File lib/sequel/database/misc.rb 484 def _typecast_value_string_to_decimal(value) 485 d = BigDecimal(value) 486 if d.zero? 487 # BigDecimal parsing is loose by default, returning a 0 value for 488 # invalid input. If a zero value is received, use Float to check 489 # for validity. 490 begin 491 Float(value) 492 rescue ArgumentError 493 raise InvalidValue, "invalid value for BigDecimal: #{value.inspect}" 494 end 495 end 496 d 497 end
Per adapter initialization method, empty by default.
# File lib/sequel/database/misc.rb 333 def adapter_initialize 334 end
Returns true when the object is considered blank. The only objects that are blank are nil, false, strings with all whitespace, and ones that respond true to empty?
# File lib/sequel/database/misc.rb 340 def blank_object?(obj) 341 return obj.blank? if obj.respond_to?(:blank?) 342 case obj 343 when NilClass, FalseClass 344 true 345 when Numeric, TrueClass 346 false 347 when String 348 obj.strip.empty? 349 else 350 obj.respond_to?(:empty?) ? obj.empty? : false 351 end 352 end
Return the Sequel::DatabaseError
subclass to wrap the given exception in.
# File lib/sequel/database/misc.rb 363 def database_error_class(exception, opts) 364 database_specific_error_class(exception, opts) || DatabaseError 365 end
An enumerable yielding pairs of regexps and exception classes, used to match against underlying driver exception messages in order to raise a more specific Sequel::DatabaseError
subclass.
# File lib/sequel/database/misc.rb 357 def database_error_regexps 358 DEFAULT_DATABASE_ERROR_REGEXPS 359 end
Return the SQLState for the given exception, if one can be determined
# File lib/sequel/database/misc.rb 368 def database_exception_sqlstate(exception, opts) 369 nil 370 end
Return a specific Sequel::DatabaseError
exception class if one is appropriate for the underlying exception, or nil if there is no specific exception class.
# File lib/sequel/database/misc.rb 375 def database_specific_error_class(exception, opts) 376 return DatabaseDisconnectError if disconnect_error?(exception, opts) 377 378 if sqlstate = database_exception_sqlstate(exception, opts) 379 if klass = database_specific_error_class_from_sqlstate(sqlstate) 380 return klass 381 end 382 else 383 database_error_regexps.each do |regexp, klss| 384 return klss if exception.message =~ regexp 385 end 386 end 387 388 nil 389 end
Given the SQLState, return the appropriate DatabaseError
subclass.
# File lib/sequel/database/misc.rb 397 def database_specific_error_class_from_sqlstate(sqlstate) 398 case sqlstate 399 when *NOT_NULL_CONSTRAINT_SQLSTATES 400 NotNullConstraintViolation 401 when *FOREIGN_KEY_CONSTRAINT_SQLSTATES 402 ForeignKeyConstraintViolation 403 when *UNIQUE_CONSTRAINT_SQLSTATES 404 UniqueConstraintViolation 405 when *CHECK_CONSTRAINT_SQLSTATES 406 CheckConstraintViolation 407 when *SERIALIZATION_CONSTRAINT_SQLSTATES 408 SerializationFailure 409 end 410 end
Return true if exception represents a disconnect error, false otherwise.
# File lib/sequel/database/misc.rb 413 def disconnect_error?(exception, opts) 414 opts[:disconnect] 415 end
Load extensions during initialization from the given key in opts.
# File lib/sequel/database/misc.rb 418 def initialize_load_extensions(key) 419 case exts = @opts[key] 420 when String 421 extension(*exts.split(',').map(&:to_sym)) 422 when Array 423 extension(*exts) 424 when Symbol 425 extension(exts) 426 when nil 427 # nothing 428 else 429 raise Error, "unsupported Database #{key.inspect} option: #{@opts[key].inspect}" 430 end 431 end
Convert the given exception to an appropriate Sequel::DatabaseError
subclass, keeping message and backtrace.
# File lib/sequel/database/misc.rb 435 def raise_error(exception, opts=OPTS) 436 if !opts[:classes] || Array(opts[:classes]).any?{|c| exception.is_a?(c)} 437 raise Sequel.convert_exception_class(exception, database_error_class(exception, opts)) 438 else 439 raise exception 440 end 441 end
Typecast the value to an SQL::Blob
# File lib/sequel/database/misc.rb 444 def typecast_value_blob(value) 445 value.is_a?(Sequel::SQL::Blob) ? value : Sequel::SQL::Blob.new(value) 446 end
Typecast the value to true, false, or nil
# File lib/sequel/database/misc.rb 449 def typecast_value_boolean(value) 450 case value 451 when false, 0, "0", /\Af(alse)?\z/i, /\Ano?\z/i 452 false 453 else 454 blank_object?(value) ? nil : true 455 end 456 end
Typecast the value to a Date
# File lib/sequel/database/misc.rb 459 def typecast_value_date(value) 460 case value 461 when DateTime, Time 462 Date.new(value.year, value.month, value.day) 463 when Date 464 value 465 when String 466 Sequel.string_to_date(value) 467 when Hash 468 Date.new(*[:year, :month, :day].map{|x| (value[x] || value[x.to_s]).to_i}) 469 else 470 raise InvalidValue, "invalid value for Date: #{value.inspect}" 471 end 472 end
Typecast the value to a DateTime or Time depending on Sequel.datetime_class
# File lib/sequel/database/misc.rb 475 def typecast_value_datetime(value) 476 Sequel.typecast_to_application_timestamp(value) 477 end
Typecast the value to a BigDecimal
# File lib/sequel/database/misc.rb 502 def typecast_value_decimal(value) 503 case value 504 when BigDecimal 505 value 506 when Numeric 507 BigDecimal(value.to_s) 508 when String 509 _typecast_value_string_to_decimal(value) 510 else 511 raise InvalidValue, "invalid value for BigDecimal: #{value.inspect}" 512 end 513 end
Typecast the value to an Integer
# File lib/sequel/database/misc.rb 519 def typecast_value_integer(value) 520 (value.is_a?(String) && value =~ /\A0+(\d)/) ? Integer(value, 10) : Integer(value) 521 end
Typecast the value to a String
# File lib/sequel/database/misc.rb 524 def typecast_value_string(value) 525 case value 526 when Hash, Array 527 raise Sequel::InvalidValue, "invalid value for String: #{value.inspect}" 528 else 529 value.to_s 530 end 531 end
Typecast the value to a Time
# File lib/sequel/database/misc.rb 534 def typecast_value_time(value) 535 case value 536 when Time 537 if value.is_a?(SQLTime) 538 value 539 else 540 SQLTime.create(value.hour, value.min, value.sec, value.nsec/1000.0) 541 end 542 when String 543 Sequel.string_to_time(value) 544 when Hash 545 SQLTime.create(*[:hour, :minute, :second].map{|x| (value[x] || value[x.to_s]).to_i}) 546 else 547 raise Sequel::InvalidValue, "invalid value for Time: #{value.inspect}" 548 end 549 end
9 - Methods that describe what the database supports
↑ topPublic Instance Methods
Whether the database uses a global namespace for the index, true by default. If false, the indexes are going to be namespaced per table.
# File lib/sequel/database/features.rb 13 def global_index_namespace? 14 true 15 end
Whether the database supports CREATE TABLE IF NOT EXISTS syntax, false by default.
# File lib/sequel/database/features.rb 19 def supports_create_table_if_not_exists? 20 false 21 end
Whether the database supports deferrable constraints, false by default as few databases do.
# File lib/sequel/database/features.rb 25 def supports_deferrable_constraints? 26 false 27 end
Whether the database supports deferrable foreign key constraints, false by default as few databases do.
# File lib/sequel/database/features.rb 31 def supports_deferrable_foreign_key_constraints? 32 supports_deferrable_constraints? 33 end
Whether the database supports DROP TABLE IF EXISTS syntax, false by default.
# File lib/sequel/database/features.rb 37 def supports_drop_table_if_exists? 38 supports_create_table_if_not_exists? 39 end
Whether the database supports Database#foreign_key_list for parsing foreign keys.
# File lib/sequel/database/features.rb 43 def supports_foreign_key_parsing? 44 respond_to?(:foreign_key_list) 45 end
Whether the database supports Database#indexes for parsing indexes.
# File lib/sequel/database/features.rb 48 def supports_index_parsing? 49 respond_to?(:indexes) 50 end
Whether the database supports partial indexes (indexes on a subset of a table), false by default.
# File lib/sequel/database/features.rb 54 def supports_partial_indexes? 55 false 56 end
Whether the database and adapter support prepared transactions (two-phase commit), false by default.
# File lib/sequel/database/features.rb 60 def supports_prepared_transactions? 61 false 62 end
Whether the database and adapter support savepoints, false by default.
# File lib/sequel/database/features.rb 65 def supports_savepoints? 66 false 67 end
Whether the database and adapter support savepoints inside prepared transactions (two-phase commit), false by default.
# File lib/sequel/database/features.rb 71 def supports_savepoints_in_prepared_transactions? 72 supports_prepared_transactions? && supports_savepoints? 73 end
Whether the database supports schema parsing via Database#schema
.
# File lib/sequel/database/features.rb 76 def supports_schema_parsing? 77 respond_to?(:schema_parse_table, true) 78 end
Whether the database supports Database#tables for getting list of tables.
# File lib/sequel/database/features.rb 81 def supports_table_listing? 82 respond_to?(:tables) 83 end
Whether the database and adapter support transaction isolation levels, false by default.
# File lib/sequel/database/features.rb 91 def supports_transaction_isolation_levels? 92 false 93 end
Whether DDL statements work correctly in transactions, false by default.
# File lib/sequel/database/features.rb 96 def supports_transactional_ddl? 97 false 98 end
Whether the database supports Database#views for getting list of views.
# File lib/sequel/database/features.rb 86 def supports_view_listing? 87 respond_to?(:views) 88 end
Whether CREATE VIEW … WITH CHECK OPTION is supported, false by default.
# File lib/sequel/database/features.rb 101 def supports_views_with_check_option? 102 !!view_with_check_option_support 103 end
Whether CREATE VIEW … WITH LOCAL CHECK OPTION is supported, false by default.
# File lib/sequel/database/features.rb 106 def supports_views_with_local_check_option? 107 view_with_check_option_support == :local 108 end
Private Instance Methods
Whether the database supports adding primary key constraints on NULLable columns, automatically making them NOT NULL. If false, the columns must be set NOT NULL before the primary key constraint is added.
# File lib/sequel/database/features.rb 115 def can_add_primary_key_constraint_on_nullable_columns? 116 true 117 end
Whether this dataset considers unquoted identifiers as uppercase. True by default as that is the SQL
standard
# File lib/sequel/database/features.rb 121 def folds_unquoted_identifiers_to_uppercase? 122 true 123 end
Whether the database supports combining multiple alter table operations into a single query, false by default.
# File lib/sequel/database/features.rb 127 def supports_combining_alter_table_ops? 128 false 129 end
Whether the database supports CREATE OR REPLACE VIEW. If not, support will be emulated by dropping the view first. false by default.
# File lib/sequel/database/features.rb 133 def supports_create_or_replace_view? 134 false 135 end
Whether the database supports named column constraints. True by default. Those that don't support named column constraints have to have column constraints converted to table constraints if the column constraints have names.
# File lib/sequel/database/features.rb 141 def supports_named_column_constraints? 142 true 143 end
Don't advertise support for WITH CHECK OPTION by default.
# File lib/sequel/database/features.rb 146 def view_with_check_option_support 147 nil 148 end