Module: Sequel::Postgres::DatasetMethods

Includes:
UnmodifiedIdentifiers::DatasetMethods
Included in:
JDBC::Postgres::Dataset, Dataset
Defined in:
lib/sequel/adapters/shared/postgres.rb

Constant Summary collapse

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

Instance Method Summary collapse

Instance Method Details

#analyze ⇒ Object

Return the results of an EXPLAIN ANALYZE query as a string



2034
2035
2036
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2034

def analyze
  explain(:analyze=>true)
end

#complex_expression_sql_append(sql, op, args) ⇒ Object

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



2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2041

def complex_expression_sql_append(sql, op, args)
  case op
  when :^
    j = ' # '
    c = false
    args.each do |a|
      sql << j if c
      literal_append(sql, a)
      c ||= true
    end
  when :ILIKE, :'NOT ILIKE'
    sql << '('
    literal_append(sql, args[0])
    sql << ' ' << op.to_s << ' '
    literal_append(sql, args[1])
    sql << ')'
  else
    super
  end
end

#disable_insert_returning ⇒ Object

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).



2076
2077
2078
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2076

def disable_insert_returning
  clone(:disable_insert_returning=>true)
end

#empty? ⇒ Boolean

Always return false when using VALUES

Returns:

  • (Boolean) 


2081
2082
2083
2084
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2081

def empty?
  return false if @opts[:values]
  super
end

#explain(opts = OPTS) ⇒ Object

Return the results of an EXPLAIN query. Boolean options:

:analyze :: Use the ANALYZE option. :buffers :: Use the BUFFERS option. :costs :: Use the COSTS option. :generic_plan :: Use the GENERIC_PLAN option. :memory :: Use the MEMORY option. :settings :: Use the SETTINGS option. :summary :: Use the SUMMARY option. :timing :: Use the TIMING option. :verbose :: Use the VERBOSE option. :wal :: Use the WAL option.

Non boolean options:

:format :: Use the FORMAT option to change the format of the returned value. Values can be :text, :xml, :json, or :yaml. :serialize :: Use the SERIALIZE option to get timing on serialization. Values can be :none, :text, or :binary.

See the PostgreSQL EXPLAIN documentation for an explanation of what each option does.

In most cases, the return value is a single string. However, using the format: :json option can result in the return value being an array containing a hash.



2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2114

def explain(opts=OPTS)
  rows = clone(:append_sql=>explain_sql_string_origin(opts)).map(:'QUERY PLAN')

  if rows.length == 1
    rows[0]
  elsif rows.all?{|row| String === row}
    rows.join("\r\n") 
  # :nocov:
  else
    # This branch is unreachable in tests, but it seems better to just return
    # all rows than throw in error if this case actually happens.
    rows
  # :nocov:
  end
end

#for_key_share ⇒ Object

Return a cloned dataset which will use FOR KEY SHARE to lock returned rows. Supported on PostgreSQL 9.3+.



2132
2133
2134
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2132

def for_key_share
  cached_lock_style_dataset(:_for_key_share_ds, :key_share)
end

#for_no_key_update ⇒ Object

Return a cloned dataset which will use FOR NO KEY UPDATE to lock returned rows. This is generally a better choice than using for_update on PostgreSQL, unless you will be deleting the row or modifying a key column. Supported on PostgreSQL 9.3+.



2159
2160
2161
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2159

def for_no_key_update
  cached_lock_style_dataset(:_for_no_key_update_ds, :no_key_update)
end

#for_portion_of(column, range, to = (arg_not_given=true)) ⇒ Object

Set FOR PORTION OF clause for UPDATE and DELETE statements. The first argument is the range or multirange column. If two arguments are provided, the second argument is an expression with the same database type as the first argument. If three arguments are provided, the second specifies the inclusive start of the portion to update and the third specifies the exclusive end of portion to update. When using the three argument form, nil can be provided as the second or third argument to have the start or end of the portion be unbounded. Supported on PostgreSQL 19+. Example:

DB[:t].for_portion_of(:rc, Sequel.function(:int4range, 1, 2)).update(c: 3)
# UPDATE t FOR PORTION OF rc (int4range(1, 2)) SET c = 3

DB[:t].for_portion_of(:rc, 1, 2).update(c: 3)
# UPDATE t FOR PORTION OF rc FROM 1 TO 2 SET c = 3


2151
2152
2153
2154
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2151

def for_portion_of(column, range, to=(arg_not_given=true))
  range = [range, to].freeze unless arg_not_given
  clone(:for_portion_of => [column, range].freeze)
end

#for_share ⇒ Object

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



2164
2165
2166
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2164

def for_share
  cached_lock_style_dataset(:_for_share_ds, :share)
end

#full_text_search(cols, terms, opts = OPTS) ⇒ Object

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, :phrase, or :websearch 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.



2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2187

def full_text_search(cols, terms, opts = OPTS)
  lang = Sequel.cast(opts[:language] || 'simple', :regconfig)

  unless opts[:tsvector]
    phrase_cols = full_text_string_join(cols)
    cols = Sequel.function(:to_tsvector, lang, phrase_cols)
  end

  unless opts[:tsquery]
    phrase_terms = terms.is_a?(Array) || terms.is_a?(Set) ? Sequel.array_or_set_join(terms, ' | ') : terms

    query_func = case to_tsquery = opts[:to_tsquery]
    when :phrase, :plain
      :"#{to_tsquery}to_tsquery"
    when :websearch
      :"websearch_to_tsquery"
    else
      (opts[:phrase] || opts[:plain]) ? :plainto_tsquery : :to_tsquery
    end

    terms = Sequel.function(query_func, lang, phrase_terms)
  end

  ds = where(Sequel.lit(["", " @@ ", ""], cols, terms))

  if opts[:phrase]
    raise Error, "can't use :phrase with either :tsvector or :tsquery arguments to full_text_search together" if opts[:tsvector] || opts[:tsquery]
    ds = ds.grep(phrase_cols, "%#{escape_like(phrase_terms)}%", :case_insensitive=>true)
  end

  if opts[:rank]
    ds = ds.reverse{ts_rank_cd(cols, terms)}
  end

  if opts[:headline]
    ds = ds.select_append{ts_headline(lang, phrase_cols, terms).as(:headline)}
  end

  ds
end

#insert(*values) ⇒ Object

Insert given values into the database.



2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2229

def insert(*values)
  if @opts[:returning]
    # Already know which columns to return, let the standard code handle it
    super
  elsif @opts[:sql] || @opts[:disable_insert_returning]
    # Raw SQL used or RETURNING disabled, just use the default behavior
    # and return nil since sequence is not known.
    super
    nil
  else
    # Force the use of RETURNING with the primary key value,
    # unless it has been disabled.
    returning(insert_pk).insert(*values){|r| return r.values.first}
  end
end

#insert_conflict(opts = OPTS) ⇒ Object

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)


2280
2281
2282
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2280

def insert_conflict(opts=OPTS)
  clone(:insert_conflict => opts)
end

#insert_ignore ⇒ Object

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


2290
2291
2292
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2290

def insert_ignore
  insert_conflict
end

#insert_select(*values) ⇒ Object

Insert a record, returning the record inserted, using RETURNING. Always returns nil without running an INSERT statement if disable_insert_returning is used. If the query runs but returns no values, returns false.



2297
2298
2299
2300
2301
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2297

def insert_select(*values)
  return unless supports_insert_select?
  # Handle case where query does not return a row
  server?(:default).with_sql_first(insert_select_sql(*values)) || false
end

#insert_select_sql(*values) ⇒ Object

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



2305
2306
2307
2308
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2305

def insert_select_sql(*values)
  ds = opts[:returning] ? self : returning
  ds.insert_sql(*values)
end

#join_table(type, table, expr = nil, options = OPTS, &block) ⇒ Object

Support SQL::AliasedExpression as expr to setup a USING join with a table alias for the USING columns.



2312
2313
2314
2315
2316
2317
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2312

def join_table(type, table, expr=nil, options=OPTS, &block)
  if expr.is_a?(SQL::AliasedExpression) && expr.expression.is_a?(Array) && !expr.expression.empty? && expr.expression.all?
    options = options.merge(:join_using=>true)
  end
  super
end

#lock(mode, opts = OPTS) ⇒ Object

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.



2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2324

def lock(mode, opts=OPTS)
  if defined?(yield) # perform locking inside a transaction and yield to block
    @db.transaction(opts){lock(mode, opts); yield}
  else
    sql = 'LOCK TABLE '.dup
    source_list_append(sql, @opts[:from])
    mode = mode.to_s.upcase.strip
    unless LOCK_MODES.include?(mode)
      raise Error, "Unsupported lock mode: #{mode}"
    end
    sql << " IN #{mode} MODE"
    @db.execute(sql, opts)
  end
  nil
end

#merge(&block) ⇒ Object

Support MERGE RETURNING on PostgreSQL 17+.



2341
2342
2343
2344
2345
2346
2347
2348
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2341

def merge(&block)
  sql = merge_sql
  if uses_returning?(:merge)
    returning_fetch_rows(sql, &block)
  else
    execute_ddl(sql)
  end
end

#merge_delete_when_not_matched_by_source(&block) ⇒ Object

Return a dataset with a WHEN NOT MATCHED BY SOURCE THEN DELETE clause added to the MERGE statement. If a block is passed, treat it as a virtual row and use it as additional conditions for the match.

merge_delete_not_matched_by_source
# WHEN NOT MATCHED BY SOURCE THEN DELETE

merge_delete_not_matched_by_source{a > 30}
# WHEN NOT MATCHED BY SOURCE AND (a > 30) THEN DELETE


2359
2360
2361
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2359

def merge_delete_when_not_matched_by_source(&block)
  _merge_when(:type=>:delete_not_matched_by_source, &block)
end

#merge_do_nothing_when_matched(&block) ⇒ Object

Return a dataset with a WHEN MATCHED THEN DO NOTHING clause added to the MERGE statement. If a block is passed, treat it as a virtual row and use it as additional conditions for the match.

merge_do_nothing_when_matched
# WHEN MATCHED THEN DO NOTHING

merge_do_nothing_when_matched{a > 30}
# WHEN MATCHED AND (a > 30) THEN DO NOTHING


2372
2373
2374
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2372

def merge_do_nothing_when_matched(&block)
  _merge_when(:type=>:matched, &block)
end

#merge_do_nothing_when_not_matched(&block) ⇒ Object

Return a dataset with a WHEN NOT MATCHED THEN DO NOTHING clause added to the MERGE statement. If a block is passed, treat it as a virtual row and use it as additional conditions for the match.

merge_do_nothing_when_not_matched
# WHEN NOT MATCHED THEN DO NOTHING

merge_do_nothing_when_not_matched{a > 30}
# WHEN NOT MATCHED AND (a > 30) THEN DO NOTHING


2385
2386
2387
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2385

def merge_do_nothing_when_not_matched(&block)
  _merge_when(:type=>:not_matched, &block)
end

#merge_do_nothing_when_not_matched_by_source(&block) ⇒ Object

Return a dataset with a WHEN NOT MATCHED BY SOURCE THEN DO NOTHING clause added to the MERGE BY SOURCE statement. If a block is passed, treat it as a virtual row and use it as additional conditions for the match.

merge_do_nothing_when_not_matched_by_source
# WHEN NOT MATCHED BY SOURCE THEN DO NOTHING

merge_do_nothing_when_not_matched_by_source{a > 30}
# WHEN NOT MATCHED BY SOURCE AND (a > 30) THEN DO NOTHING


2398
2399
2400
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2398

def merge_do_nothing_when_not_matched_by_source(&block)
  _merge_when(:type=>:not_matched_by_source, &block)
end

#merge_insert(*values, &block) ⇒ Object

Support OVERRIDING USER|SYSTEM VALUE for MERGE INSERT.



2403
2404
2405
2406
2407
2408
2409
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2403

def merge_insert(*values, &block)
  h = {:type=>:insert, :values=>values}
  if @opts[:override]
    h[:override] = insert_override_sql(String.new)
  end
  _merge_when(h, &block)
end

#merge_update_when_not_matched_by_source(values, &block) ⇒ Object

Return a dataset with a WHEN NOT MATCHED BY SOURCE THEN UPDATE clause added to the MERGE statement. If a block is passed, treat it as a virtual row and use it as additional conditions for the match.

merge_update_not_matched_by_source(i1: Sequel[:i1]+:i2+10, a: Sequel[:a]+:b+20)
# WHEN NOT MATCHED BY SOURCE THEN UPDATE SET i1 = (i1 + i2 + 10), a = (a + b + 20)

merge_update_not_matched_by_source(i1: :i2){a > 30}
# WHEN NOT MATCHED BY SOURCE AND (a > 30) THEN UPDATE SET i1 = i2


2420
2421
2422
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2420

def merge_update_when_not_matched_by_source(values, &block)
  _merge_when(:type=>:update_not_matched_by_source, :values=>values, &block)
end

#overriding_system_value ⇒ Object

Use OVERRIDING USER VALUE for INSERT statements, so that identity columns always use the user supplied value, and an error is not raised for identity columns that are GENERATED ALWAYS.



2427
2428
2429
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2427

def overriding_system_value
  clone(:override=>:system)
end

#overriding_user_value ⇒ Object

Use OVERRIDING USER VALUE for INSERT statements, so that identity columns always use the sequence value instead of the user supplied value.



2433
2434
2435
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2433

def overriding_user_value
  clone(:override=>:user)
end

#supports_cte?(type = :select) ⇒ Boolean

Returns:

  • (Boolean) 


2437
2438
2439
2440
2441
2442
2443
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2437

def supports_cte?(type=:select)
  if type == :select
    server_version >= 80400
  else
    server_version >= 90100
  end
end

#supports_cte_in_subqueries? ⇒ Boolean

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

Returns:

  • (Boolean) 


2447
2448
2449
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2447

def supports_cte_in_subqueries?
  supports_cte?
end

#supports_distinct_on? ⇒ Boolean

DISTINCT ON is a PostgreSQL extension

Returns:

  • (Boolean) 


2452
2453
2454
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2452

def supports_distinct_on?
  true
end

#supports_group_cube? ⇒ Boolean

PostgreSQL 9.5+ supports GROUP CUBE

Returns:

  • (Boolean) 


2457
2458
2459
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2457

def supports_group_cube?
  server_version >= 90500
end

#supports_group_rollup? ⇒ Boolean

PostgreSQL 9.5+ supports GROUP ROLLUP

Returns:

  • (Boolean) 


2462
2463
2464
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2462

def supports_group_rollup?
  server_version >= 90500
end

#supports_grouping_sets? ⇒ Boolean

PostgreSQL 9.5+ supports GROUPING SETS

Returns:

  • (Boolean) 


2467
2468
2469
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2467

def supports_grouping_sets?
  server_version >= 90500
end

#supports_insert_conflict? ⇒ Boolean

PostgreSQL 9.5+ supports the ON CONFLICT clause to INSERT.

Returns:

  • (Boolean) 


2477
2478
2479
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2477

def supports_insert_conflict?
  server_version >= 90500
end

#supports_insert_select? ⇒ Boolean

True unless insert returning has been disabled for this dataset.

Returns:

  • (Boolean) 


2472
2473
2474
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2472

def supports_insert_select?
  !@opts[:disable_insert_returning]
end

#supports_lateral_subqueries? ⇒ Boolean

PostgreSQL 9.3+ supports lateral subqueries

Returns:

  • (Boolean) 


2482
2483
2484
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2482

def supports_lateral_subqueries?
  server_version >= 90300
end

#supports_merge? ⇒ Boolean

PostgreSQL 15+ supports MERGE.

Returns:

  • (Boolean) 


2492
2493
2494
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2492

def supports_merge?
  server_version >= 150000
end

#supports_modifying_joins? ⇒ Boolean

PostgreSQL supports modifying joined datasets

Returns:

  • (Boolean) 


2487
2488
2489
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2487

def supports_modifying_joins?
  true
end

#supports_nowait? ⇒ Boolean

PostgreSQL supports NOWAIT.

Returns:

  • (Boolean) 


2497
2498
2499
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2497

def supports_nowait?
  true
end

#supports_regexp? ⇒ Boolean

PostgreSQL supports pattern matching via regular expressions

Returns:

  • (Boolean) 


2512
2513
2514
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2512

def supports_regexp?
  true
end

#supports_returning?(type) ⇒ Boolean

MERGE RETURNING is supported on PostgreSQL 17+. Other RETURNING is supported on all supported PostgreSQL versions.

Returns:

  • (Boolean) 


2503
2504
2505
2506
2507
2508
2509
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2503

def supports_returning?(type)
  if type == :merge
    server_version >= 170000
  else
    true
  end
end

#supports_skip_locked? ⇒ Boolean

PostgreSQL 9.5+ supports SKIP LOCKED.

Returns:

  • (Boolean) 


2517
2518
2519
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2517

def supports_skip_locked?
  server_version >= 90500
end

#supports_timestamp_timezones? ⇒ Boolean

PostgreSQL supports timezones in literal timestamps

Returns:

  • (Boolean) 


2524
2525
2526
2527
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2524

def supports_timestamp_timezones?
  # SEQUEL6: Remove
  true
end

#supports_window_clause? ⇒ Boolean

PostgreSQL 8.4+ supports WINDOW clause.

Returns:

  • (Boolean) 


2531
2532
2533
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2531

def supports_window_clause?
  server_version >= 80400
end

#supports_window_function_frame_option?(option) ⇒ Boolean

Base support added in 8.4, offset supported added in 9.0, GROUPS and EXCLUDE support added in 11.0.

Returns:

  • (Boolean) 


2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2542

def supports_window_function_frame_option?(option)
  case option
  when :rows, :range
    true
  when :offset
    server_version >= 90000
  when :groups, :exclude
    server_version >= 110000
  else
    false
  end
end

#supports_window_functions? ⇒ Boolean

PostgreSQL 8.4+ supports window functions

Returns:

  • (Boolean) 


2536
2537
2538
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2536

def supports_window_functions?
  server_version >= 80400
end

#truncate(opts = OPTS) ⇒ Object

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


2571
2572
2573
2574
2575
2576
2577
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2571

def truncate(opts = OPTS)
  if opts.empty?
    super()
  else
    clone(:truncate_opts=>opts).truncate
  end
end

#with_ties ⇒ Object

Use WITH TIES when limiting the result set to also include additional rules that have the same results for the order column as the final row. Requires PostgreSQL 13.



2582
2583
2584
 
# File 'lib/sequel/adapters/shared/postgres.rb', line 2582

def with_ties
  clone(:limit_with_ties=>true)
end