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. | |
RESET_PROCS_EXTENSIONS | = | [:pg_array, :pg_hstore, :pg_inet, :pg_interval, :pg_json, :pg_range].freeze | The Sequel extensions that require reseting of the conversion procs. |
conversion_procs | [R] | A hash of conversion procs, keyed by type integer (oid) and having callable values for the conversion proc for that type. |
Commit an existing prepared transaction with the given transaction identifier string.
# File lib/sequel/adapters/shared/postgres.rb, line 163 163: def commit_prepared_transaction(transaction_id) 164: run("COMMIT PREPARED #{literal(transaction_id)}") 165: end
Creates the function in the database. Arguments:
# File lib/sequel/adapters/shared/postgres.rb, line 187 187: def create_function(name, definition, opts={}) 188: self << create_function_sql(name, definition, opts) 189: end
Create the procedural language in the database. Arguments:
# File lib/sequel/adapters/shared/postgres.rb, line 198 198: def create_language(name, opts={}) 199: self << create_language_sql(name, opts) 200: end
Create a schema in the database. Arguments:
# File lib/sequel/adapters/shared/postgres.rb, line 204 204: def create_schema(name) 205: self << create_schema_sql(name) 206: end
Create a trigger in the database. Arguments:
# File lib/sequel/adapters/shared/postgres.rb, line 218 218: def create_trigger(table, name, function, opts={}) 219: self << create_trigger_sql(table, name, function, opts) 220: end
PostgreSQL uses the :postgres database type.
# File lib/sequel/adapters/shared/postgres.rb, line 223 223: def database_type 224: :postgres 225: end
Drops the function from the database. Arguments:
# File lib/sequel/adapters/shared/postgres.rb, line 233 233: def drop_function(name, opts={}) 234: self << drop_function_sql(name, opts) 235: end
Drops a procedural language from the database. Arguments:
# File lib/sequel/adapters/shared/postgres.rb, line 242 242: def drop_language(name, opts={}) 243: self << drop_language_sql(name, opts) 244: end
Drops a schema from the database. Arguments:
# File lib/sequel/adapters/shared/postgres.rb, line 251 251: def drop_schema(name, opts={}) 252: self << drop_schema_sql(name, opts) 253: end
Drops a trigger from the database. Arguments:
# File lib/sequel/adapters/shared/postgres.rb, line 261 261: def drop_trigger(table, name, opts={}) 262: self << drop_trigger_sql(table, name, opts) 263: end
If any of the extensions that require reseting the conversion procs is loaded, reset them. This is done here so that if you load multiple pg_* extensions in the same call, the conversion procs are only reset once instead of once for every extension.
# File lib/sequel/adapters/shared/postgres.rb, line 269 269: def extension(*exts) 270: super 271: unless (RESET_PROCS_EXTENSIONS & exts).empty? 272: reset_conversion_procs 273: end 274: 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 278 278: def foreign_key_list(table, opts={}) 279: m = output_identifier_meth 280: im = input_identifier_meth 281: schema, table = schema_and_table(table) 282: range = 0...32 283: 284: base_ds = metadata_dataset. 285: where(:cl__relkind=>'r', :co__contype=>'f', :cl__relname=>im.call(table)). 286: from(:pg_constraint___co). 287: join(:pg_class___cl, :oid=>:conrelid) 288: 289: # We split the parsing into two separate queries, which are merged manually later. 290: # This is because PostgreSQL stores both the referencing and referenced columns in 291: # arrays, and I don't know a simple way to not create a cross product, as PostgreSQL 292: # doesn't appear to have a function that takes an array and element and gives you 293: # the index of that element in the array. 294: 295: ds = base_ds. 296: join(:pg_attribute___att, :attrelid=>:oid, :attnum=>SQL::Function.new(:ANY, :co__conkey)). 297: order(:co__conname, SQL::CaseExpression.new(range.map{|x| [SQL::Subscript.new(:co__conkey, [x]), x]}, 32, :att__attnum)). 298: select(:co__conname___name, :att__attname___column, :co__confupdtype___on_update, :co__confdeltype___on_delete, 299: SQL::BooleanExpression.new(:AND, :co__condeferrable, :co__condeferred).as(:deferrable)) 300: 301: ref_ds = base_ds. 302: join(:pg_class___cl2, :oid=>:co__confrelid). 303: join(:pg_attribute___att2, :attrelid=>:oid, :attnum=>SQL::Function.new(:ANY, :co__confkey)). 304: order(:co__conname, SQL::CaseExpression.new(range.map{|x| [SQL::Subscript.new(:co__conkey, [x]), x]}, 32, :att2__attnum)). 305: select(:co__conname___name, :cl2__relname___table, :att2__attname___refcolumn) 306: 307: # If a schema is given, we only search in that schema, and the returned :table 308: # entry is schema qualified as well. 309: if schema 310: ds = ds.join(:pg_namespace___nsp, :oid=>:cl__relnamespace). 311: where(:nsp__nspname=>im.call(schema)) 312: ref_ds = ref_ds.join(:pg_namespace___nsp2, :oid=>:cl2__relnamespace). 313: select_more(:nsp2__nspname___schema) 314: end 315: 316: h = {} 317: fklod_map = FOREIGN_KEY_LIST_ON_DELETE_MAP 318: ds.each do |row| 319: if r = h[row[:name]] 320: r[:columns] << m.call(row[:column]) 321: else 322: 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]} 323: end 324: end 325: ref_ds.each do |row| 326: r = h[row[:name]] 327: r[:table] ||= schema ? SQL::QualifiedIdentifier.new(m.call(row[:schema]), m.call(row[:table])) : m.call(row[:table]) 328: r[:key] ||= [] 329: r[:key] << m.call(row[:refcolumn]) 330: end 331: h.values 332: end
Use the pg_* system tables to determine indexes on a table
# File lib/sequel/adapters/shared/postgres.rb, line 335 335: def indexes(table, opts={}) 336: m = output_identifier_meth 337: im = input_identifier_meth 338: schema, table = schema_and_table(table) 339: range = 0...32 340: attnums = server_version >= 80100 ? SQL::Function.new(:ANY, :ind__indkey) : range.map{|x| SQL::Subscript.new(:ind__indkey, [x])} 341: ds = metadata_dataset. 342: from(:pg_class___tab). 343: join(:pg_index___ind, :indrelid=>:oid, im.call(table)=>:relname). 344: join(:pg_class___indc, :oid=>:indexrelid). 345: join(:pg_attribute___att, :attrelid=>:tab__oid, :attnum=>attnums). 346: filter(:indc__relkind=>'i', :ind__indisprimary=>false, :indexprs=>nil, :indpred=>nil, :indisvalid=>true). 347: order(:indc__relname, SQL::CaseExpression.new(range.map{|x| [SQL::Subscript.new(:ind__indkey, [x]), x]}, 32, :att__attnum)). 348: select(:indc__relname___name, :ind__indisunique___unique, :att__attname___column) 349: 350: ds.join!(:pg_namespace___nsp, :oid=>:tab__relnamespace, :nspname=>schema.to_s) if schema 351: ds.filter!(:indisready=>true, :indcheckxmin=>false) if server_version >= 80300 352: 353: indexes = {} 354: ds.each do |r| 355: i = indexes[m.call(r[:name])] ||= {:columns=>[], :unique=>r[:unique]} 356: i[:columns] << m.call(r[:column]) 357: end 358: indexes 359: 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 372 372: def notify(channel, opts={}) 373: execute_ddl("NOTIFY #{channel}#{", #{literal(opts[:payload].to_s)}" if opts[:payload]}", opts) 374: end
Return primary key for the given table.
# File lib/sequel/adapters/shared/postgres.rb, line 377 377: def primary_key(table, opts={}) 378: quoted_table = quote_schema_table(table) 379: @primary_keys.fetch(quoted_table) do 380: schema, table = schema_and_table(table) 381: sql = "#{SELECT_PK_SQL} AND pg_class.relname = #{literal(table)}" 382: sql << "AND pg_namespace.nspname = #{literal(schema)}" if schema 383: @primary_keys[quoted_table] = fetch(sql).single_value 384: end 385: end
Return the sequence providing the default for the primary key for the given table.
# File lib/sequel/adapters/shared/postgres.rb, line 388 388: def primary_key_sequence(table, opts={}) 389: quoted_table = quote_schema_table(table) 390: @primary_key_sequences.fetch(quoted_table) do 391: schema, table = schema_and_table(table) 392: table = literal(table) 393: sql = "#{SELECT_SERIAL_SEQUENCE_SQL} AND seq.relname = #{table}" 394: sql << " AND name.nspname = #{literal(schema)}" if schema 395: unless pks = fetch(sql).single_record 396: sql = "#{SELECT_CUSTOM_SEQUENCE_SQL} AND t.relname = #{table}" 397: sql << " AND name.nspname = #{literal(schema)}" if schema 398: pks = fetch(sql).single_record 399: end 400: 401: @primary_key_sequences[quoted_table] = if pks 402: literal(SQL::QualifiedIdentifier.new(pks[:schema], LiteralString.new(pks[:sequence]))) 403: end 404: end 405: end
Reset the database‘s conversion procs, requires a server query if there any named types.
# File lib/sequel/adapters/shared/postgres.rb, line 409 409: def reset_conversion_procs 410: @conversion_procs = get_conversion_procs 411: 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 415 415: def reset_primary_key_sequence(table) 416: return unless seq = primary_key_sequence(table) 417: pk = SQL::Identifier.new(primary_key(table)) 418: db = self 419: seq_ds = db.from(LiteralString.new(seq)) 420: get{setval(seq, db[table].select{coalesce(max(pk)+seq_ds.select{:increment_by}, seq_ds.select(:min_value))}, false)} 421: end
PostgreSQL uses SERIAL psuedo-type instead of AUTOINCREMENT for managing incrementing primary keys.
# File lib/sequel/adapters/shared/postgres.rb, line 431 431: def serial_primary_key_options 432: {:primary_key => true, :serial => true, :type=>Integer} 433: end
The version of the PostgreSQL server, used for determining capability.
# File lib/sequel/adapters/shared/postgres.rb, line 436 436: def server_version(server=nil) 437: return @server_version if @server_version 438: @server_version = synchronize(server) do |conn| 439: (conn.server_version rescue nil) if conn.respond_to?(:server_version) 440: end 441: unless @server_version 442: @server_version = if m = /PostgreSQL (\d+)\.(\d+)(?:(?:rc\d+)|\.(\d+))?/.match(fetch('SELECT version()').single_value) 443: (m[1].to_i * 10000) + (m[2].to_i * 100) + m[3].to_i 444: else 445: 0 446: end 447: end 448: warn 'Sequel no longer supports PostgreSQL <8.2, some things may not work' if @server_version < 80200 449: @server_version 450: end
PostgreSQL supports CREATE TABLE IF NOT EXISTS on 9.1+
# File lib/sequel/adapters/shared/postgres.rb, line 453 453: def supports_create_table_if_not_exists? 454: server_version >= 90100 455: end
PostgreSQL supports DROP TABLE IF EXISTS
# File lib/sequel/adapters/shared/postgres.rb, line 458 458: def supports_drop_table_if_exists? 459: true 460: end
PostgreSQL supports prepared transactions (two-phase commit) if max_prepared_transactions is greater than 0.
# File lib/sequel/adapters/shared/postgres.rb, line 464 464: def supports_prepared_transactions? 465: return @supports_prepared_transactions if defined?(@supports_prepared_transactions) 466: @supports_prepared_transactions = self['SHOW max_prepared_transactions'].get.to_i > 0 467: end
PostgreSQL supports savepoints
# File lib/sequel/adapters/shared/postgres.rb, line 470 470: def supports_savepoints? 471: true 472: end
PostgreSQL supports transaction isolation levels
# File lib/sequel/adapters/shared/postgres.rb, line 475 475: def supports_transaction_isolation_levels? 476: true 477: end
PostgreSQL supports transaction DDL statements.
# File lib/sequel/adapters/shared/postgres.rb, line 480 480: def supports_transactional_ddl? 481: true 482: 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 491 491: def tables(opts={}, &block) 492: pg_class_relname('r', opts, &block) 493: 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 497 497: def type_supported?(type) 498: @supported_types ||= {} 499: @supported_types.fetch(type){@supported_types[type] = (from(:pg_type).filter(:typtype=>'b', :typname=>type.to_s).count > 0)} 500: end