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
1914 def analyze
1915   explain(:analyze=>true)
1916 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
1921 def complex_expression_sql_append(sql, op, args)
1922   case op
1923   when :^
1924     j = ' # '
1925     c = false
1926     args.each do |a|
1927       sql << j if c
1928       literal_append(sql, a)
1929       c ||= true
1930     end
1931   when :ILIKE, :'NOT ILIKE'
1932     sql << '('
1933     literal_append(sql, args[0])
1934     sql << ' ' << op.to_s << ' '
1935     literal_append(sql, args[1])
1936     sql << ')'
1937   else
1938     super
1939   end
1940 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
1956 def disable_insert_returning
1957   clone(:disable_insert_returning=>true)
1958 end
empty?()

Always return false when using VALUES

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
1961 def empty?
1962   return false if @opts[:values]
1963   super
1964 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
1994 def explain(opts=OPTS)
1995   rows = clone(:append_sql=>explain_sql_string_origin(opts)).map(:'QUERY PLAN')
1996 
1997   if rows.length == 1
1998     rows[0]
1999   elsif rows.all?{|row| String === row}
2000     rows.join("\r\n") 
2001   # :nocov:
2002   else
2003     # This branch is unreachable in tests, but it seems better to just return
2004     # all rows than throw in error if this case actually happens.
2005     rows
2006   # :nocov:
2007   end
2008 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
2012 def for_key_share
2013   cached_lock_style_dataset(:_for_key_share_ds, :key_share)
2014 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
2019 def for_no_key_update
2020   cached_lock_style_dataset(:_for_no_key_update_ds, :no_key_update)
2021 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
2024 def for_share
2025   cached_lock_style_dataset(:_for_share_ds, :share)
2026 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
2047 def full_text_search(cols, terms, opts = OPTS)
2048   lang = Sequel.cast(opts[:language] || 'simple', :regconfig)
2049 
2050   unless opts[:tsvector]
2051     phrase_cols = full_text_string_join(cols)
2052     cols = Sequel.function(:to_tsvector, lang, phrase_cols)
2053   end
2054 
2055   unless opts[:tsquery]
2056     phrase_terms = terms.is_a?(Array) ? terms.join(' | ') : terms
2057 
2058     query_func = case to_tsquery = opts[:to_tsquery]
2059     when :phrase, :plain
2060       :"#{to_tsquery}to_tsquery"
2061     when :websearch
2062       :"websearch_to_tsquery"
2063     else
2064       (opts[:phrase] || opts[:plain]) ? :plainto_tsquery : :to_tsquery
2065     end
2066 
2067     terms = Sequel.function(query_func, lang, phrase_terms)
2068   end
2069 
2070   ds = where(Sequel.lit(["", " @@ ", ""], cols, terms))
2071 
2072   if opts[:phrase]
2073     raise Error, "can't use :phrase with either :tsvector or :tsquery arguments to full_text_search together" if opts[:tsvector] || opts[:tsquery]
2074     ds = ds.grep(phrase_cols, "%#{escape_like(phrase_terms)}%", :case_insensitive=>true)
2075   end
2076 
2077   if opts[:rank]
2078     ds = ds.reverse{ts_rank_cd(cols, terms)}
2079   end
2080 
2081   if opts[:headline]
2082     ds = ds.select_append{ts_headline(lang, phrase_cols, terms).as(:headline)}
2083   end
2084 
2085   ds
2086 end
insert(*values)

Insert given values into the database.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2089 def insert(*values)
2090   if @opts[:returning]
2091     # Already know which columns to return, let the standard code handle it
2092     super
2093   elsif @opts[:sql] || @opts[:disable_insert_returning]
2094     # Raw SQL used or RETURNING disabled, just use the default behavior
2095     # and return nil since sequence is not known.
2096     super
2097     nil
2098   else
2099     # Force the use of RETURNING with the primary key value,
2100     # unless it has been disabled.
2101     returning(insert_pk).insert(*values){|r| return r.values.first}
2102   end
2103 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
2140 def insert_conflict(opts=OPTS)
2141   clone(:insert_conflict => opts)
2142 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
2150 def insert_ignore
2151   insert_conflict
2152 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
2157 def insert_select(*values)
2158   return unless supports_insert_select?
2159   # Handle case where query does not return a row
2160   server?(:default).with_sql_first(insert_select_sql(*values)) || false
2161 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
2165 def insert_select_sql(*values)
2166   ds = opts[:returning] ? self : returning
2167   ds.insert_sql(*values)
2168 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
2172 def join_table(type, table, expr=nil, options=OPTS, &block)
2173   if expr.is_a?(SQL::AliasedExpression) && expr.expression.is_a?(Array) && !expr.expression.empty? && expr.expression.all?
2174     options = options.merge(:join_using=>true)
2175   end
2176   super
2177 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
2184 def lock(mode, opts=OPTS)
2185   if defined?(yield) # perform locking inside a transaction and yield to block
2186     @db.transaction(opts){lock(mode, opts); yield}
2187   else
2188     sql = 'LOCK TABLE '.dup
2189     source_list_append(sql, @opts[:from])
2190     mode = mode.to_s.upcase.strip
2191     unless LOCK_MODES.include?(mode)
2192       raise Error, "Unsupported lock mode: #{mode}"
2193     end
2194     sql << " IN #{mode} MODE"
2195     @db.execute(sql, opts)
2196   end
2197   nil
2198 end
merge(&block)

Support MERGE RETURNING on PostgreSQL 17+.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2201 def merge(&block)
2202   sql = merge_sql
2203   if uses_returning?(:merge)
2204     returning_fetch_rows(sql, &block)
2205   else
2206     execute_ddl(sql)
2207   end
2208 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
2219 def merge_delete_when_not_matched_by_source(&block)
2220   _merge_when(:type=>:delete_not_matched_by_source, &block)
2221 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
2232 def merge_do_nothing_when_matched(&block)
2233   _merge_when(:type=>:matched, &block)
2234 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
2245 def merge_do_nothing_when_not_matched(&block)
2246   _merge_when(:type=>:not_matched, &block)
2247 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
2258 def merge_do_nothing_when_not_matched_by_source(&block)
2259   _merge_when(:type=>:not_matched_by_source, &block)
2260 end
merge_insert(*values, &block)

Support OVERRIDING USER|SYSTEM VALUE for MERGE INSERT.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2263 def merge_insert(*values, &block)
2264   h = {:type=>:insert, :values=>values}
2265   if @opts[:override]
2266     h[:override] = insert_override_sql(String.new)
2267   end
2268   _merge_when(h, &block)
2269 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
2280 def merge_update_when_not_matched_by_source(values, &block)
2281   _merge_when(:type=>:update_not_matched_by_source, :values=>values, &block)
2282 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
2287 def overriding_system_value
2288   clone(:override=>:system)
2289 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
2293 def overriding_user_value
2294   clone(:override=>:user)
2295 end
supports_cte?(type=:select)
[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2297 def supports_cte?(type=:select)
2298   if type == :select
2299     server_version >= 80400
2300   else
2301     server_version >= 90100
2302   end
2303 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
2307 def supports_cte_in_subqueries?
2308   supports_cte?
2309 end
supports_distinct_on?()

DISTINCT ON is a PostgreSQL extension

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2312 def supports_distinct_on?
2313   true
2314 end
supports_group_cube?()

PostgreSQL 9.5+ supports GROUP CUBE

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2317 def supports_group_cube?
2318   server_version >= 90500
2319 end
supports_group_rollup?()

PostgreSQL 9.5+ supports GROUP ROLLUP

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2322 def supports_group_rollup?
2323   server_version >= 90500
2324 end
supports_grouping_sets?()

PostgreSQL 9.5+ supports GROUPING SETS

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2327 def supports_grouping_sets?
2328   server_version >= 90500
2329 end
supports_insert_conflict?()

PostgreSQL 9.5+ supports the ON CONFLICT clause to INSERT.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2337 def supports_insert_conflict?
2338   server_version >= 90500
2339 end
supports_insert_select?()

True unless insert returning has been disabled for this dataset.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2332 def supports_insert_select?
2333   !@opts[:disable_insert_returning]
2334 end
supports_lateral_subqueries?()

PostgreSQL 9.3+ supports lateral subqueries

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2342 def supports_lateral_subqueries?
2343   server_version >= 90300
2344 end
supports_merge?()

PostgreSQL 15+ supports MERGE.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2352 def supports_merge?
2353   server_version >= 150000
2354 end
supports_modifying_joins?()

PostgreSQL supports modifying joined datasets

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2347 def supports_modifying_joins?
2348   true
2349 end
supports_nowait?()

PostgreSQL supports NOWAIT.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2357 def supports_nowait?
2358   true
2359 end
supports_regexp?()

PostgreSQL supports pattern matching via regular expressions

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2372 def supports_regexp?
2373   true
2374 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
2363 def supports_returning?(type)
2364   if type == :merge
2365     server_version >= 170000
2366   else
2367     true
2368   end
2369 end
supports_skip_locked?()

PostgreSQL 9.5+ supports SKIP LOCKED.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2377 def supports_skip_locked?
2378   server_version >= 90500
2379 end
supports_timestamp_timezones?()

PostgreSQL supports timezones in literal timestamps

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2384 def supports_timestamp_timezones?
2385   # SEQUEL6: Remove
2386   true
2387 end
supports_window_clause?()

PostgreSQL 8.4+ supports WINDOW clause.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2391 def supports_window_clause?
2392   server_version >= 80400
2393 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
2402 def supports_window_function_frame_option?(option)
2403   case option
2404   when :rows, :range
2405     true
2406   when :offset
2407     server_version >= 90000
2408   when :groups, :exclude
2409     server_version >= 110000
2410   else
2411     false
2412   end
2413 end
supports_window_functions?()

PostgreSQL 8.4+ supports window functions

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2396 def supports_window_functions?
2397   server_version >= 80400
2398 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
2431 def truncate(opts = OPTS)
2432   if opts.empty?
2433     super()
2434   else
2435     clone(:truncate_opts=>opts).truncate
2436   end
2437 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
2442 def with_ties
2443   clone(:limit_with_ties=>true)
2444 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
2452 def _import(columns, values, opts=OPTS)
2453   if @opts[:returning]
2454     # no transaction: our multi_insert_sql_strategy should guarantee
2455     # that there's only ever a single statement.
2456     sql = multi_insert_sql(columns, values)[0]
2457     returning_fetch_rows(sql).map{|v| v.length == 1 ? v.values.first : v}
2458   elsif opts[:return] == :primary_key
2459     returning(insert_pk)._import(columns, values, opts)
2460   else
2461     super
2462   end
2463 end
to_prepared_statement(type, *a)
[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2465 def to_prepared_statement(type, *a)
2466   if type == :insert && !@opts.has_key?(:returning)
2467     returning(insert_pk).send(:to_prepared_statement, :insert_pk, *a)
2468   else
2469     super
2470   end
2471 end