module Sequel::Postgres::DatasetMethods

  1. lib/sequel/adapters/shared/postgres.rb

Constants

EXPLAIN_BOOLEAN_OPTIONS = {}  
EXPLAIN_NONBOOLEAN_OPTIONS = { :serialize => {:none=>"SERIALIZE NONE", :text=>"SERIALIZE TEXT", :binary=>"SERIALIZE BINARY"}.freeze, :format => {:text=>"FORMAT TEXT", :xml=>"FORMAT XML", :json=>"FORMAT JSON", :yaml=>"FORMAT YAML"}.freeze }.freeze  
LOCK_MODES = ['ACCESS SHARE', 'ROW SHARE', 'ROW EXCLUSIVE', 'SHARE UPDATE EXCLUSIVE', 'SHARE', 'SHARE ROW EXCLUSIVE', 'EXCLUSIVE', 'ACCESS EXCLUSIVE'].each(&:freeze).freeze  
NULL = LiteralString.new('NULL').freeze  

Public Instance methods

analyze()

Return the results of an EXPLAIN ANALYZE query as a string

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2021 def analyze
2022   explain(:analyze=>true)
2023 end
complex_expression_sql_append(sql, op, args)

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

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2028 def complex_expression_sql_append(sql, op, args)
2029   case op
2030   when :^
2031     j = ' # '
2032     c = false
2033     args.each do |a|
2034       sql << j if c
2035       literal_append(sql, a)
2036       c ||= true
2037     end
2038   when :ILIKE, :'NOT ILIKE'
2039     sql << '('
2040     literal_append(sql, args[0])
2041     sql << ' ' << op.to_s << ' '
2042     literal_append(sql, args[1])
2043     sql << ')'
2044   else
2045     super
2046   end
2047 end
disable_insert_returning()

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).

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2063 def disable_insert_returning
2064   clone(:disable_insert_returning=>true)
2065 end
empty?()

Always return false when using VALUES

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2068 def empty?
2069   return false if @opts[:values]
2070   super
2071 end
explain(opts=OPTS)

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.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2101 def explain(opts=OPTS)
2102   rows = clone(:append_sql=>explain_sql_string_origin(opts)).map(:'QUERY PLAN')
2103 
2104   if rows.length == 1
2105     rows[0]
2106   elsif rows.all?{|row| String === row}
2107     rows.join("\r\n") 
2108   # :nocov:
2109   else
2110     # This branch is unreachable in tests, but it seems better to just return
2111     # all rows than throw in error if this case actually happens.
2112     rows
2113   # :nocov:
2114   end
2115 end
for_key_share()

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

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2119 def for_key_share
2120   cached_lock_style_dataset(:_for_key_share_ds, :key_share)
2121 end
for_no_key_update()

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+.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2126 def for_no_key_update
2127   cached_lock_style_dataset(:_for_no_key_update_ds, :no_key_update)
2128 end
for_share()

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

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2131 def for_share
2132   cached_lock_style_dataset(:_for_share_ds, :share)
2133 end
full_text_search(cols, terms, opts = OPTS)

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.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2154 def full_text_search(cols, terms, opts = OPTS)
2155   lang = Sequel.cast(opts[:language] || 'simple', :regconfig)
2156 
2157   unless opts[:tsvector]
2158     phrase_cols = full_text_string_join(cols)
2159     cols = Sequel.function(:to_tsvector, lang, phrase_cols)
2160   end
2161 
2162   unless opts[:tsquery]
2163     phrase_terms = terms.is_a?(Array) ? terms.join(' | ') : terms
2164 
2165     query_func = case to_tsquery = opts[:to_tsquery]
2166     when :phrase, :plain
2167       :"#{to_tsquery}to_tsquery"
2168     when :websearch
2169       :"websearch_to_tsquery"
2170     else
2171       (opts[:phrase] || opts[:plain]) ? :plainto_tsquery : :to_tsquery
2172     end
2173 
2174     terms = Sequel.function(query_func, lang, phrase_terms)
2175   end
2176 
2177   ds = where(Sequel.lit(["", " @@ ", ""], cols, terms))
2178 
2179   if opts[:phrase]
2180     raise Error, "can't use :phrase with either :tsvector or :tsquery arguments to full_text_search together" if opts[:tsvector] || opts[:tsquery]
2181     ds = ds.grep(phrase_cols, "%#{escape_like(phrase_terms)}%", :case_insensitive=>true)
2182   end
2183 
2184   if opts[:rank]
2185     ds = ds.reverse{ts_rank_cd(cols, terms)}
2186   end
2187 
2188   if opts[:headline]
2189     ds = ds.select_append{ts_headline(lang, phrase_cols, terms).as(:headline)}
2190   end
2191 
2192   ds
2193 end
insert(*values)

Insert given values into the database.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2196 def insert(*values)
2197   if @opts[:returning]
2198     # Already know which columns to return, let the standard code handle it
2199     super
2200   elsif @opts[:sql] || @opts[:disable_insert_returning]
2201     # Raw SQL used or RETURNING disabled, just use the default behavior
2202     # and return nil since sequence is not known.
2203     super
2204     nil
2205   else
2206     # Force the use of RETURNING with the primary key value,
2207     # unless it has been disabled.
2208     returning(insert_pk).insert(*values){|r| return r.values.first}
2209   end
2210 end
insert_conflict(opts=OPTS)

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)
[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2247 def insert_conflict(opts=OPTS)
2248   clone(:insert_conflict => opts)
2249 end
insert_ignore()

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
[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2257 def insert_ignore
2258   insert_conflict
2259 end
insert_select(*values)

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.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2264 def insert_select(*values)
2265   return unless supports_insert_select?
2266   # Handle case where query does not return a row
2267   server?(:default).with_sql_first(insert_select_sql(*values)) || false
2268 end
insert_select_sql(*values)

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

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2272 def insert_select_sql(*values)
2273   ds = opts[:returning] ? self : returning
2274   ds.insert_sql(*values)
2275 end
join_table(type, table, expr=nil, options=OPTS, &block)

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

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2279 def join_table(type, table, expr=nil, options=OPTS, &block)
2280   if expr.is_a?(SQL::AliasedExpression) && expr.expression.is_a?(Array) && !expr.expression.empty? && expr.expression.all?
2281     options = options.merge(:join_using=>true)
2282   end
2283   super
2284 end
lock(mode, opts=OPTS)

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.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2291 def lock(mode, opts=OPTS)
2292   if defined?(yield) # perform locking inside a transaction and yield to block
2293     @db.transaction(opts){lock(mode, opts); yield}
2294   else
2295     sql = 'LOCK TABLE '.dup
2296     source_list_append(sql, @opts[:from])
2297     mode = mode.to_s.upcase.strip
2298     unless LOCK_MODES.include?(mode)
2299       raise Error, "Unsupported lock mode: #{mode}"
2300     end
2301     sql << " IN #{mode} MODE"
2302     @db.execute(sql, opts)
2303   end
2304   nil
2305 end
merge(&block)

Support MERGE RETURNING on PostgreSQL 17+.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2308 def merge(&block)
2309   sql = merge_sql
2310   if uses_returning?(:merge)
2311     returning_fetch_rows(sql, &block)
2312   else
2313     execute_ddl(sql)
2314   end
2315 end
merge_delete_when_not_matched_by_source(&block)

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
[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2326 def merge_delete_when_not_matched_by_source(&block)
2327   _merge_when(:type=>:delete_not_matched_by_source, &block)
2328 end
merge_do_nothing_when_matched(&block)

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
[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2339 def merge_do_nothing_when_matched(&block)
2340   _merge_when(:type=>:matched, &block)
2341 end
merge_do_nothing_when_not_matched(&block)

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
[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2352 def merge_do_nothing_when_not_matched(&block)
2353   _merge_when(:type=>:not_matched, &block)
2354 end
merge_do_nothing_when_not_matched_by_source(&block)

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
[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2365 def merge_do_nothing_when_not_matched_by_source(&block)
2366   _merge_when(:type=>:not_matched_by_source, &block)
2367 end
merge_insert(*values, &block)

Support OVERRIDING USER|SYSTEM VALUE for MERGE INSERT.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2370 def merge_insert(*values, &block)
2371   h = {:type=>:insert, :values=>values}
2372   if @opts[:override]
2373     h[:override] = insert_override_sql(String.new)
2374   end
2375   _merge_when(h, &block)
2376 end
merge_update_when_not_matched_by_source(values, &block)

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
[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2387 def merge_update_when_not_matched_by_source(values, &block)
2388   _merge_when(:type=>:update_not_matched_by_source, :values=>values, &block)
2389 end
overriding_system_value()

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.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2394 def overriding_system_value
2395   clone(:override=>:system)
2396 end
overriding_user_value()

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

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2400 def overriding_user_value
2401   clone(:override=>:user)
2402 end
supports_cte?(type=:select)
[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2404 def supports_cte?(type=:select)
2405   if type == :select
2406     server_version >= 80400
2407   else
2408     server_version >= 90100
2409   end
2410 end
supports_cte_in_subqueries?()

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

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2414 def supports_cte_in_subqueries?
2415   supports_cte?
2416 end
supports_distinct_on?()

DISTINCT ON is a PostgreSQL extension

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2419 def supports_distinct_on?
2420   true
2421 end
supports_group_cube?()

PostgreSQL 9.5+ supports GROUP CUBE

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2424 def supports_group_cube?
2425   server_version >= 90500
2426 end
supports_group_rollup?()

PostgreSQL 9.5+ supports GROUP ROLLUP

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2429 def supports_group_rollup?
2430   server_version >= 90500
2431 end
supports_grouping_sets?()

PostgreSQL 9.5+ supports GROUPING SETS

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2434 def supports_grouping_sets?
2435   server_version >= 90500
2436 end
supports_insert_conflict?()

PostgreSQL 9.5+ supports the ON CONFLICT clause to INSERT.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2444 def supports_insert_conflict?
2445   server_version >= 90500
2446 end
supports_insert_select?()

True unless insert returning has been disabled for this dataset.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2439 def supports_insert_select?
2440   !@opts[:disable_insert_returning]
2441 end
supports_lateral_subqueries?()

PostgreSQL 9.3+ supports lateral subqueries

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2449 def supports_lateral_subqueries?
2450   server_version >= 90300
2451 end
supports_merge?()

PostgreSQL 15+ supports MERGE.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2459 def supports_merge?
2460   server_version >= 150000
2461 end
supports_modifying_joins?()

PostgreSQL supports modifying joined datasets

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2454 def supports_modifying_joins?
2455   true
2456 end
supports_nowait?()

PostgreSQL supports NOWAIT.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2464 def supports_nowait?
2465   true
2466 end
supports_regexp?()

PostgreSQL supports pattern matching via regular expressions

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2479 def supports_regexp?
2480   true
2481 end
supports_returning?(type)

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

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2470 def supports_returning?(type)
2471   if type == :merge
2472     server_version >= 170000
2473   else
2474     true
2475   end
2476 end
supports_skip_locked?()

PostgreSQL 9.5+ supports SKIP LOCKED.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2484 def supports_skip_locked?
2485   server_version >= 90500
2486 end
supports_timestamp_timezones?()

PostgreSQL supports timezones in literal timestamps

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2491 def supports_timestamp_timezones?
2492   # SEQUEL6: Remove
2493   true
2494 end
supports_window_clause?()

PostgreSQL 8.4+ supports WINDOW clause.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2498 def supports_window_clause?
2499   server_version >= 80400
2500 end
supports_window_function_frame_option?(option)

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

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2509 def supports_window_function_frame_option?(option)
2510   case option
2511   when :rows, :range
2512     true
2513   when :offset
2514     server_version >= 90000
2515   when :groups, :exclude
2516     server_version >= 110000
2517   else
2518     false
2519   end
2520 end
supports_window_functions?()

PostgreSQL 8.4+ supports window functions

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2503 def supports_window_functions?
2504   server_version >= 80400
2505 end
truncate(opts = OPTS)

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
[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2538 def truncate(opts = OPTS)
2539   if opts.empty?
2540     super()
2541   else
2542     clone(:truncate_opts=>opts).truncate
2543   end
2544 end
with_ties()

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.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2549 def with_ties
2550   clone(:limit_with_ties=>true)
2551 end

Protected Instance methods

_import(columns, values, opts=OPTS)

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.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2559 def _import(columns, values, opts=OPTS)
2560   if @opts[:returning]
2561     # no transaction: our multi_insert_sql_strategy should guarantee
2562     # that there's only ever a single statement.
2563     sql = multi_insert_sql(columns, values)[0]
2564     returning_fetch_rows(sql).map{|v| v.length == 1 ? v.values.first : v}
2565   elsif opts[:return] == :primary_key
2566     returning(insert_pk)._import(columns, values, opts)
2567   else
2568     super
2569   end
2570 end
to_prepared_statement(type, *a)
[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2572 def to_prepared_statement(type, *a)
2573   if type == :insert && !@opts.has_key?(:returning)
2574     returning(insert_pk).send(:to_prepared_statement, :insert_pk, *a)
2575   else
2576     super
2577   end
2578 end