Module Sequel::DatasetMethods
In: lib/sequel/adapters/shared/postgres.rb

Methods

Included Modules

UnmodifiedIdentifiers::DatasetMethods

Constants

NULL = LiteralString.new('NULL').freeze
LOCK_MODES = ['ACCESS SHARE', 'ROW SHARE', 'ROW EXCLUSIVE', 'SHARE UPDATE EXCLUSIVE', 'SHARE', 'SHARE ROW EXCLUSIVE', 'EXCLUSIVE', 'ACCESS EXCLUSIVE'].each(&:freeze).freeze

Public Instance methods

Return the results of an EXPLAIN ANALYZE query as a string

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1209
1209:       def analyze
1210:         explain(:analyze=>true)
1211:       end

Handle converting the ruby xor operator (^) into the PostgreSQL xor operator (#), and use the ILIKE and NOT ILIKE operators.

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1216
1216:       def complex_expression_sql_append(sql, op, args)
1217:         case op
1218:         when :^
1219:           j = ' # '
1220:           c = false
1221:           args.each do |a|
1222:             sql << j if c
1223:             literal_append(sql, a)
1224:             c ||= true
1225:           end
1226:         when :ILIKE, 'NOT ILIKE''NOT ILIKE'
1227:           sql << '('
1228:           literal_append(sql, args[0])
1229:           sql << ' ' << op.to_s << ' '
1230:           literal_append(sql, args[1])
1231:           sql << " ESCAPE "
1232:           literal_append(sql, "\\")
1233:           sql << ')'
1234:         else
1235:           super
1236:         end
1237:       end

Disables automatic use of INSERT … RETURNING. You can still use returning manually to force the use of RETURNING when inserting.

This is designed for cases where INSERT RETURNING cannot be used, such as when you are using partitioning with trigger functions or conditional rules, or when you are using a PostgreSQL version less than 8.2, or a PostgreSQL derivative that does not support returning.

Note that when this method is used, insert will not return the primary key of the inserted row, you will have to get the primary key of the inserted row before inserting via nextval, or after inserting via currval or lastval (making sure to use the same database connection for currval or lastval).

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1253
1253:       def disable_insert_returning
1254:         clone(:disable_insert_returning=>true)
1255:       end

Return the results of an EXPLAIN query as a string

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1258
1258:       def explain(opts=OPTS)
1259:         with_sql((opts[:analyze] ? 'EXPLAIN ANALYZE ' : 'EXPLAIN ') + select_sql).map('QUERY PLAN''QUERY PLAN').join("\r\n")
1260:       end

Return a cloned dataset which will use FOR SHARE to lock returned rows.

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1263
1263:       def for_share
1264:         lock_style(:share)
1265:       end

Run a full text search on PostgreSQL. By default, searching for the inclusion of any of the terms in any of the cols.

Options:

:headline :Append a expression to the selected columns aliased to headline that contains an extract of the matched text.
:language :The language to use for the search (default: ‘simple’)
:plain :Whether a plain search should be used (default: false). In this case, terms should be a single string, and it will do a search where cols contains all of the words in terms. This ignores search operators in terms.
:phrase :Similar to :plain, but also adding an ILIKE filter to ensure that returned rows also include the exact phrase used.
:rank :Set to true to order by the rank, so that closer matches are returned first.
:to_tsquery :Can be set to :plain or :phrase to specify the function to use to convert the terms to a ts_query.
:tsquery :Specifies the terms argument is already a valid SQL expression returning a tsquery, and can be used directly in the query.
:tsvector :Specifies the cols argument is already a valid SQL expression returning a tsvector, and can be used directly in the query.

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1286
1286:       def full_text_search(cols, terms, opts = OPTS)
1287:         lang = Sequel.cast(opts[:language] || 'simple', :regconfig)
1288: 
1289:         unless opts[:tsvector]
1290:           phrase_cols = full_text_string_join(cols)
1291:           cols = Sequel.function(:to_tsvector, lang, phrase_cols)
1292:         end
1293: 
1294:         unless opts[:tsquery]
1295:           phrase_terms = terms.is_a?(Array) ? terms.join(' | ') : terms
1296: 
1297:           query_func = case to_tsquery = opts[:to_tsquery]
1298:           when :phrase, :plain
1299:             "#{to_tsquery}to_tsquery""#{to_tsquery}to_tsquery"
1300:           else
1301:             (opts[:phrase] || opts[:plain]) ? :plainto_tsquery : :to_tsquery
1302:           end
1303: 
1304:           terms = Sequel.function(query_func, lang, phrase_terms)
1305:         end
1306: 
1307:         ds = where(Sequel.lit(["", " @@ ", ""], cols, terms))
1308: 
1309:         if opts[:phrase]
1310:           raise Error, "can't use :phrase with either :tsvector or :tsquery arguments to full_text_search together" if opts[:tsvector] || opts[:tsquery]
1311:           ds = ds.grep(phrase_cols, "%#{escape_like(phrase_terms)}%", :case_insensitive=>true)
1312:         end
1313: 
1314:         if opts[:rank]
1315:           ds = ds.reverse{ts_rank_cd(cols, terms)}
1316:         end
1317: 
1318:         if opts[:headline]
1319:           ds = ds.select_append{ts_headline(lang, phrase_cols, terms).as(:headline)}
1320:         end
1321: 
1322:         ds
1323:       end

Insert given values into the database.

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1326
1326:       def insert(*values)
1327:         if @opts[:returning]
1328:           # Already know which columns to return, let the standard code handle it
1329:           super
1330:         elsif @opts[:sql] || @opts[:disable_insert_returning]
1331:           # Raw SQL used or RETURNING disabled, just use the default behavior
1332:           # and return nil since sequence is not known.
1333:           super
1334:           nil
1335:         else
1336:           # Force the use of RETURNING with the primary key value,
1337:           # unless it has been disabled.
1338:           returning(insert_pk).insert(*values){|r| return r.values.first}
1339:         end
1340:       end

Handle uniqueness violations when inserting, by updating the conflicting row, using ON CONFLICT. With no options, uses ON CONFLICT DO NOTHING. Options:

:conflict_where :The index filter, when using a partial index to determine uniqueness.
:constraint :An explicit constraint name, has precendence over :target.
:target :The column name or expression to handle uniqueness violations on.
:update :A hash of columns and values to set. Uses ON CONFLICT DO UPDATE.
:update_where :A WHERE condition to use for the update.

Examples:

  DB[:table].insert_conflict.insert(a: 1, b: 2)
  # INSERT INTO TABLE (a, b) VALUES (1, 2)
  # ON CONFLICT DO NOTHING

  DB[:table].insert_conflict(constraint: :table_a_uidx).insert(a: 1, b: 2)
  # INSERT INTO TABLE (a, b) VALUES (1, 2)
  # ON CONFLICT ON CONSTRAINT table_a_uidx DO NOTHING

  DB[:table].insert_conflict(target: :a).insert(a: 1, b: 2)
  # INSERT INTO TABLE (a, b) VALUES (1, 2)
  # ON CONFLICT (a) DO NOTHING

  DB[:table].insert_conflict(target: :a, conflict_where: {c: true}).insert(a: 1, b: 2)
  # INSERT INTO TABLE (a, b) VALUES (1, 2)
  # ON CONFLICT (a) WHERE (c IS TRUE) DO NOTHING

  DB[:table].insert_conflict(target: :a, update: {b: Sequel[:excluded][:b]}).insert(a: 1, b: 2)
  # INSERT INTO TABLE (a, b) VALUES (1, 2)
  # ON CONFLICT (a) DO UPDATE SET b = excluded.b

  DB[:table].insert_conflict(constraint: :table_a_uidx,
    update: {b: Sequel[:excluded][:b]}, update_where: {Sequel[:table][:status_id] => 1}).insert(a: 1, b: 2)
  # INSERT INTO TABLE (a, b) VALUES (1, 2)
  # ON CONFLICT ON CONSTRAINT table_a_uidx
  # DO UPDATE SET b = excluded.b WHERE (table.status_id = 1)

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1377
1377:       def insert_conflict(opts=OPTS)
1378:         clone(:insert_conflict => opts)
1379:       end

Ignore uniqueness/exclusion violations when inserting, using ON CONFLICT DO NOTHING. Exists mostly for compatibility to MySQL‘s insert_ignore. Example:

  DB[:table].insert_ignore.insert(a: 1, b: 2)
  # INSERT INTO TABLE (a, b) VALUES (1, 2)
  # ON CONFLICT DO NOTHING

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1387
1387:       def insert_ignore
1388:         insert_conflict
1389:       end

Insert a record returning the record inserted. Always returns nil without inserting a query if disable_insert_returning is used.

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1393
1393:       def insert_select(*values)
1394:         return unless supports_insert_select?
1395:         server?(:default).with_sql_first(insert_select_sql(*values))
1396:       end

The SQL to use for an insert_select, adds a RETURNING clause to the insert unless the RETURNING clause is already present.

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1400
1400:       def insert_select_sql(*values)
1401:         ds = opts[:returning] ? self : returning
1402:         ds.insert_sql(*values)
1403:       end

Locks all tables in the dataset‘s FROM clause (but not in JOINs) with the specified mode (e.g. ‘EXCLUSIVE’). If a block is given, starts a new transaction, locks the table, and yields. If a block is not given, just locks the tables. Note that PostgreSQL will probably raise an error if you lock the table outside of an existing transaction. Returns nil.

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1410
1410:       def lock(mode, opts=OPTS)
1411:         if block_given? # perform locking inside a transaction and yield to block
1412:           @db.transaction(opts){lock(mode, opts); yield}
1413:         else
1414:           sql = 'LOCK TABLE '.dup
1415:           source_list_append(sql, @opts[:from])
1416:           mode = mode.to_s.upcase.strip
1417:           unless LOCK_MODES.include?(mode)
1418:             raise Error, "Unsupported lock mode: #{mode}"
1419:           end
1420:           sql << " IN #{mode} MODE"
1421:           @db.execute(sql, opts)
1422:         end
1423:         nil
1424:       end

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1426
1426:       def supports_cte?(type=:select)
1427:         if type == :select
1428:           server_version >= 80400
1429:         else
1430:           server_version >= 90100
1431:         end
1432:       end

PostgreSQL supports using the WITH clause in subqueries if it supports using WITH at all (i.e. on PostgreSQL 8.4+).

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1436
1436:       def supports_cte_in_subqueries?
1437:         supports_cte?
1438:       end

DISTINCT ON is a PostgreSQL extension

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1441
1441:       def supports_distinct_on?
1442:         true
1443:       end

PostgreSQL 9.5+ supports GROUP CUBE

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1446
1446:       def supports_group_cube?
1447:         server_version >= 90500
1448:       end

PostgreSQL 9.5+ supports GROUP ROLLUP

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1451
1451:       def supports_group_rollup?
1452:         server_version >= 90500
1453:       end

PostgreSQL 9.5+ supports GROUPING SETS

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1456
1456:       def supports_grouping_sets?
1457:         server_version >= 90500
1458:       end

PostgreSQL 9.5+ supports the ON CONFLICT clause to INSERT.

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1466
1466:       def supports_insert_conflict?
1467:         server_version >= 90500
1468:       end

True unless insert returning has been disabled for this dataset.

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1461
1461:       def supports_insert_select?
1462:         !@opts[:disable_insert_returning]
1463:       end

PostgreSQL 9.3+ supports lateral subqueries

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1471
1471:       def supports_lateral_subqueries?
1472:         server_version >= 90300
1473:       end

PostgreSQL supports modifying joined datasets

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1476
1476:       def supports_modifying_joins?
1477:         true
1478:       end

PostgreSQL supports pattern matching via regular expressions

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1486
1486:       def supports_regexp?
1487:         true
1488:       end

Returning is always supported.

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1481
1481:       def supports_returning?(type)
1482:         true
1483:       end

PostgreSQL 9.5+ supports SKIP LOCKED.

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1491
1491:       def supports_skip_locked?
1492:         server_version >= 90500
1493:       end

PostgreSQL supports timezones in literal timestamps

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1496
1496:       def supports_timestamp_timezones?
1497:         true
1498:       end

PostgreSQL 8.4+ supports window functions

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1501
1501:       def supports_window_functions?
1502:         server_version >= 80400
1503:       end

Truncates the dataset. Returns nil.

Options:

:cascade :whether to use the CASCADE option, useful when truncating tables with foreign keys.
:only :truncate using ONLY, so child tables are unaffected
:restart :use RESTART IDENTITY to restart any related sequences

:only and :restart only work correctly on PostgreSQL 8.4+.

Usage:

  DB[:table].truncate
  # TRUNCATE TABLE "table"

  DB[:table].truncate(cascade: true, only: true, restart: true)
  # TRUNCATE TABLE ONLY "table" RESTART IDENTITY CASCADE

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1521
1521:       def truncate(opts = OPTS)
1522:         if opts.empty?
1523:           super()
1524:         else
1525:           clone(:truncate_opts=>opts).truncate
1526:         end
1527:       end

Return a clone of the dataset with an addition named window that can be referenced in window functions. See {SQL::Window} for a list of options that can be passed in.

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1532
1532:       def window(name, opts)
1533:         clone(:window=>(@opts[:window]||[]) + [[name, SQL::Window.new(opts)]])
1534:       end

Protected Instance methods

If returned primary keys are requested, use RETURNING unless already set on the dataset. If RETURNING is already set, use existing returning values. If RETURNING is only set to return a single columns, return an array of just that column. Otherwise, return an array of hashes.

[Source]

      # File lib/sequel/adapters/shared/postgres.rb, line 1542
1542:       def _import(columns, values, opts=OPTS)
1543:         if @opts[:returning]
1544:           statements = multi_insert_sql(columns, values)
1545:           @db.transaction(Hash[opts].merge!(:server=>@opts[:server])) do
1546:             statements.map{|st| returning_fetch_rows(st)}
1547:           end.first.map{|v| v.length == 1 ? v.values.first : v}
1548:         elsif opts[:return] == :primary_key
1549:           returning(insert_pk)._import(columns, values, opts)
1550:         else
1551:           super
1552:         end
1553:       end

[Validate]