Module | Sequel::Postgres::DatabaseMethods |
In: |
lib/sequel/adapters/shared/postgres.rb
|
Methods shared by Database instances that connect to PostgreSQL.
EXCLUDE_SCHEMAS | = | /pg_*|information_schema/i | ||
PREPARED_ARG_PLACEHOLDER | = | LiteralString.new('$').freeze | ||
RE_CURRVAL_ERROR | = | /currval of sequence "(.*)" is not yet defined in this session|relation "(.*)" does not exist/.freeze | ||
SYSTEM_TABLE_REGEXP | = | /^pg|sql/.freeze | ||
FOREIGN_KEY_LIST_ON_DELETE_MAP | = | {'a'.freeze=>:no_action, 'r'.freeze=>:restrict, 'c'.freeze=>:cascade, 'n'.freeze=>:set_null, 'd'.freeze=>:set_default}.freeze | ||
SELECT_CUSTOM_SEQUENCE_SQL | = | (<<-end_sql SELECT name.nspname AS "schema", CASE WHEN split_part(def.adsrc, '''', 2) ~ '.' THEN substr(split_part(def.adsrc, '''', 2), strpos(split_part(def.adsrc, '''', 2), '.')+1) ELSE split_part(def.adsrc, '''', 2) END AS "sequence" FROM pg_class t JOIN pg_namespace name ON (t.relnamespace = name.oid) JOIN pg_attribute attr ON (t.oid = attrelid) JOIN pg_attrdef def ON (adrelid = attrelid AND adnum = attnum) JOIN pg_constraint cons ON (conrelid = adrelid AND adnum = conkey[1]) WHERE cons.contype = 'p' AND def.adsrc ~* 'nextval' end_sql | SQL fragment for custom sequences (ones not created by serial primary key), Returning the schema and literal form of the sequence name, by parsing the column defaults table. | |
SELECT_PK_SQL | = | (<<-end_sql SELECT pg_attribute.attname AS pk FROM pg_class, pg_attribute, pg_index, pg_namespace WHERE pg_class.oid = pg_attribute.attrelid AND pg_class.relnamespace = pg_namespace.oid AND pg_class.oid = pg_index.indrelid AND pg_index.indkey[0] = pg_attribute.attnum AND pg_index.indisprimary = 't' end_sql | SQL fragment for determining primary key column for the given table. Only returns the first primary key if the table has a composite primary key. | |
SELECT_SERIAL_SEQUENCE_SQL | = | (<<-end_sql SELECT name.nspname AS "schema", seq.relname AS "sequence" FROM pg_class seq, pg_attribute attr, pg_depend dep, pg_namespace name, pg_constraint cons WHERE seq.oid = dep.objid AND seq.relnamespace = name.oid AND seq.relkind = 'S' AND attr.attrelid = dep.refobjid AND attr.attnum = dep.refobjsubid AND attr.attrelid = cons.conrelid AND attr.attnum = cons.conkey[1] AND cons.contype = 'p' end_sql | SQL fragment for getting sequence associated with table‘s primary key, assuming it was a serial primary key column. |
Commit an existing prepared transaction with the given transaction identifier string.
# File lib/sequel/adapters/shared/postgres.rb, line 117 117: def commit_prepared_transaction(transaction_id) 118: run("COMMIT PREPARED #{literal(transaction_id)}") 119: end
Creates the function in the database. Arguments:
# File lib/sequel/adapters/shared/postgres.rb, line 141 141: def create_function(name, definition, opts={}) 142: self << create_function_sql(name, definition, opts) 143: end
Create the procedural language in the database. Arguments:
# File lib/sequel/adapters/shared/postgres.rb, line 152 152: def create_language(name, opts={}) 153: self << create_language_sql(name, opts) 154: end
Create a schema in the database. Arguments:
# File lib/sequel/adapters/shared/postgres.rb, line 158 158: def create_schema(name) 159: self << create_schema_sql(name) 160: end
Create a trigger in the database. Arguments:
# File lib/sequel/adapters/shared/postgres.rb, line 172 172: def create_trigger(table, name, function, opts={}) 173: self << create_trigger_sql(table, name, function, opts) 174: end
PostgreSQL uses the :postgres database type.
# File lib/sequel/adapters/shared/postgres.rb, line 177 177: def database_type 178: :postgres 179: end
Drops the function from the database. Arguments:
# File lib/sequel/adapters/shared/postgres.rb, line 187 187: def drop_function(name, opts={}) 188: self << drop_function_sql(name, opts) 189: end
Drops a procedural language from the database. Arguments:
# File lib/sequel/adapters/shared/postgres.rb, line 196 196: def drop_language(name, opts={}) 197: self << drop_language_sql(name, opts) 198: end
Drops a schema from the database. Arguments:
# File lib/sequel/adapters/shared/postgres.rb, line 205 205: def drop_schema(name, opts={}) 206: self << drop_schema_sql(name, opts) 207: end
Drops a trigger from the database. Arguments:
# File lib/sequel/adapters/shared/postgres.rb, line 215 215: def drop_trigger(table, name, opts={}) 216: self << drop_trigger_sql(table, name, opts) 217: end
Return full foreign key information using the pg system tables, including :name, :on_delete, :on_update, and :deferrable entries in the hashes.
# File lib/sequel/adapters/shared/postgres.rb, line 221 221: def foreign_key_list(table, opts={}) 222: m = output_identifier_meth 223: im = input_identifier_meth 224: schema, table = schema_and_table(table) 225: range = 0...32 226: 227: base_ds = metadata_dataset. 228: where(:cl__relkind=>'r', :co__contype=>'f', :cl__relname=>im.call(table)). 229: from(:pg_constraint___co). 230: join(:pg_class___cl, :oid=>:conrelid) 231: 232: # We split the parsing into two separate queries, which are merged manually later. 233: # This is because PostgreSQL stores both the referencing and referenced columns in 234: # arrays, and I don't know a simple way to not create a cross product, as PostgreSQL 235: # doesn't appear to have a function that takes an array and element and gives you 236: # the index of that element in the array. 237: 238: ds = base_ds. 239: join(:pg_attribute___att, :attrelid=>:oid, :attnum=>SQL::Function.new(:ANY, :co__conkey)). 240: order(:co__conname, SQL::CaseExpression.new(range.map{|x| [SQL::Subscript.new(:co__conkey, [x]), x]}, 32, :att__attnum)). 241: select(:co__conname___name, :att__attname___column, :co__confupdtype___on_update, :co__confdeltype___on_delete, 242: SQL::BooleanExpression.new(:AND, :co__condeferrable, :co__condeferred).as(:deferrable)) 243: 244: ref_ds = base_ds. 245: join(:pg_class___cl2, :oid=>:co__confrelid). 246: join(:pg_attribute___att2, :attrelid=>:oid, :attnum=>SQL::Function.new(:ANY, :co__confkey)). 247: order(:co__conname, SQL::CaseExpression.new(range.map{|x| [SQL::Subscript.new(:co__conkey, [x]), x]}, 32, :att2__attnum)). 248: select(:co__conname___name, :cl2__relname___table, :att2__attname___refcolumn) 249: 250: # If a schema is given, we only search in that schema, and the returned :table 251: # entry is schema qualified as well. 252: if schema 253: ds = ds.join(:pg_namespace___nsp, :oid=>:cl__relnamespace). 254: where(:nsp__nspname=>im.call(schema)) 255: ref_ds = ref_ds.join(:pg_namespace___nsp2, :oid=>:cl2__relnamespace). 256: select_more(:nsp2__nspname___schema) 257: end 258: 259: h = {} 260: fklod_map = FOREIGN_KEY_LIST_ON_DELETE_MAP 261: ds.each do |row| 262: if r = h[row[:name]] 263: r[:columns] << m.call(row[:column]) 264: else 265: h[row[:name]] = {:name=>m.call(row[:name]), :columns=>[m.call(row[:column])], :on_update=>fklod_map[row[:on_update]], :on_delete=>fklod_map[row[:on_delete]], :deferrable=>row[:deferrable]} 266: end 267: end 268: ref_ds.each do |row| 269: r = h[row[:name]] 270: r[:table] ||= schema ? SQL::QualifiedIdentifier.new(m.call(row[:schema]), m.call(row[:table])) : m.call(row[:table]) 271: r[:key] ||= [] 272: r[:key] << m.call(row[:refcolumn]) 273: end 274: h.values 275: end
Use the pg_* system tables to determine indexes on a table
# File lib/sequel/adapters/shared/postgres.rb, line 278 278: def indexes(table, opts={}) 279: m = output_identifier_meth 280: im = input_identifier_meth 281: schema, table = schema_and_table(table) 282: range = 0...32 283: attnums = server_version >= 80100 ? SQL::Function.new(:ANY, :ind__indkey) : range.map{|x| SQL::Subscript.new(:ind__indkey, [x])} 284: ds = metadata_dataset. 285: from(:pg_class___tab). 286: join(:pg_index___ind, :indrelid=>:oid, im.call(table)=>:relname). 287: join(:pg_class___indc, :oid=>:indexrelid). 288: join(:pg_attribute___att, :attrelid=>:tab__oid, :attnum=>attnums). 289: filter(:indc__relkind=>'i', :ind__indisprimary=>false, :indexprs=>nil, :indpred=>nil, :indisvalid=>true). 290: order(:indc__relname, SQL::CaseExpression.new(range.map{|x| [SQL::Subscript.new(:ind__indkey, [x]), x]}, 32, :att__attnum)). 291: select(:indc__relname___name, :ind__indisunique___unique, :att__attname___column) 292: 293: ds.join!(:pg_namespace___nsp, :oid=>:tab__relnamespace, :nspname=>schema.to_s) if schema 294: ds.filter!(:indisready=>true, :indcheckxmin=>false) if server_version >= 80300 295: 296: indexes = {} 297: ds.each do |r| 298: i = indexes[m.call(r[:name])] ||= {:columns=>[], :unique=>r[:unique]} 299: i[:columns] << m.call(r[:column]) 300: end 301: indexes 302: end
Notifies the given channel. See the PostgreSQL NOTIFY documentation. Options:
:payload : | The payload string to use for the NOTIFY statement. Only supported in PostgreSQL 9.0+. |
:server : | The server to which to send the NOTIFY statement, if the sharding support is being used. |
# File lib/sequel/adapters/shared/postgres.rb, line 315 315: def notify(channel, opts={}) 316: execute_ddl("NOTIFY #{channel}#{", #{literal(opts[:payload].to_s)}" if opts[:payload]}", opts) 317: end
Return primary key for the given table.
# File lib/sequel/adapters/shared/postgres.rb, line 320 320: def primary_key(table, opts={}) 321: quoted_table = quote_schema_table(table) 322: @primary_keys.fetch(quoted_table) do 323: schema, table = schema_and_table(table) 324: sql = "#{SELECT_PK_SQL} AND pg_class.relname = #{literal(table)}" 325: sql << "AND pg_namespace.nspname = #{literal(schema)}" if schema 326: @primary_keys[quoted_table] = fetch(sql).single_value 327: end 328: end
Return the sequence providing the default for the primary key for the given table.
# File lib/sequel/adapters/shared/postgres.rb, line 331 331: def primary_key_sequence(table, opts={}) 332: quoted_table = quote_schema_table(table) 333: @primary_key_sequences.fetch(quoted_table) do 334: schema, table = schema_and_table(table) 335: table = literal(table) 336: sql = "#{SELECT_SERIAL_SEQUENCE_SQL} AND seq.relname = #{table}" 337: sql << " AND name.nspname = #{literal(schema)}" if schema 338: unless pks = fetch(sql).single_record 339: sql = "#{SELECT_CUSTOM_SEQUENCE_SQL} AND t.relname = #{table}" 340: sql << " AND name.nspname = #{literal(schema)}" if schema 341: pks = fetch(sql).single_record 342: end 343: 344: @primary_key_sequences[quoted_table] = if pks 345: literal(SQL::QualifiedIdentifier.new(pks[:schema], LiteralString.new(pks[:sequence]))) 346: end 347: end 348: end
Reset the primary key sequence for the given table, baseing it on the maximum current value of the table‘s primary key.
# File lib/sequel/adapters/shared/postgres.rb, line 352 352: def reset_primary_key_sequence(table) 353: return unless seq = primary_key_sequence(table) 354: pk = SQL::Identifier.new(primary_key(table)) 355: db = self 356: seq_ds = db.from(LiteralString.new(seq)) 357: get{setval(seq, db[table].select{coalesce(max(pk)+seq_ds.select{:increment_by}, seq_ds.select(:min_value))}, false)} 358: end
PostgreSQL uses SERIAL psuedo-type instead of AUTOINCREMENT for managing incrementing primary keys.
# File lib/sequel/adapters/shared/postgres.rb, line 368 368: def serial_primary_key_options 369: {:primary_key => true, :serial => true, :type=>Integer} 370: end
The version of the PostgreSQL server, used for determining capability.
# File lib/sequel/adapters/shared/postgres.rb, line 373 373: def server_version(server=nil) 374: return @server_version if @server_version 375: @server_version = synchronize(server) do |conn| 376: (conn.server_version rescue nil) if conn.respond_to?(:server_version) 377: end 378: unless @server_version 379: @server_version = if m = /PostgreSQL (\d+)\.(\d+)(?:(?:rc\d+)|\.(\d+))?/.match(fetch('SELECT version()').single_value) 380: (m[1].to_i * 10000) + (m[2].to_i * 100) + m[3].to_i 381: else 382: 0 383: end 384: end 385: warn 'Sequel no longer supports PostgreSQL <8.2, some things may not work' if @server_version < 80200 386: @server_version 387: end
PostgreSQL supports CREATE TABLE IF NOT EXISTS on 9.1+
# File lib/sequel/adapters/shared/postgres.rb, line 390 390: def supports_create_table_if_not_exists? 391: server_version >= 90100 392: end
PostgreSQL supports DROP TABLE IF EXISTS
# File lib/sequel/adapters/shared/postgres.rb, line 395 395: def supports_drop_table_if_exists? 396: true 397: end
PostgreSQL supports prepared transactions (two-phase commit) if max_prepared_transactions is greater than 0.
# File lib/sequel/adapters/shared/postgres.rb, line 401 401: def supports_prepared_transactions? 402: return @supports_prepared_transactions if defined?(@supports_prepared_transactions) 403: @supports_prepared_transactions = self['SHOW max_prepared_transactions'].get.to_i > 0 404: end
PostgreSQL supports savepoints
# File lib/sequel/adapters/shared/postgres.rb, line 407 407: def supports_savepoints? 408: true 409: end
PostgreSQL supports transaction isolation levels
# File lib/sequel/adapters/shared/postgres.rb, line 412 412: def supports_transaction_isolation_levels? 413: true 414: end
PostgreSQL supports transaction DDL statements.
# File lib/sequel/adapters/shared/postgres.rb, line 417 417: def supports_transactional_ddl? 418: true 419: end
Array of symbols specifying table names in the current database. The dataset used is yielded to the block if one is provided, otherwise, an array of symbols of table names is returned.
Options:
# File lib/sequel/adapters/shared/postgres.rb, line 428 428: def tables(opts={}, &block) 429: pg_class_relname('r', opts, &block) 430: end
Check whether the given type name string/symbol (e.g. :hstore) is supported by the database.
# File lib/sequel/adapters/shared/postgres.rb, line 434 434: def type_supported?(type) 435: @supported_types ||= {} 436: @supported_types.fetch(type){@supported_types[type] = (from(:pg_type).filter(:typtype=>'b', :typname=>type.to_s).count > 0)} 437: end