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
2034 def analyze
2035   explain(:analyze=>true)
2036 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
2041 def complex_expression_sql_append(sql, op, args)
2042   case op
2043   when :^
2044     j = ' # '
2045     c = false
2046     args.each do |a|
2047       sql << j if c
2048       literal_append(sql, a)
2049       c ||= true
2050     end
2051   when :ILIKE, :'NOT ILIKE'
2052     sql << '('
2053     literal_append(sql, args[0])
2054     sql << ' ' << op.to_s << ' '
2055     literal_append(sql, args[1])
2056     sql << ')'
2057   else
2058     super
2059   end
2060 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
2076 def disable_insert_returning
2077   clone(:disable_insert_returning=>true)
2078 end
empty?()

Always return false when using VALUES

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2081 def empty?
2082   return false if @opts[:values]
2083   super
2084 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
2114 def explain(opts=OPTS)
2115   rows = clone(:append_sql=>explain_sql_string_origin(opts)).map(:'QUERY PLAN')
2116 
2117   if rows.length == 1
2118     rows[0]
2119   elsif rows.all?{|row| String === row}
2120     rows.join("\r\n") 
2121   # :nocov:
2122   else
2123     # This branch is unreachable in tests, but it seems better to just return
2124     # all rows than throw in error if this case actually happens.
2125     rows
2126   # :nocov:
2127   end
2128 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
2132 def for_key_share
2133   cached_lock_style_dataset(:_for_key_share_ds, :key_share)
2134 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
2139 def for_no_key_update
2140   cached_lock_style_dataset(:_for_no_key_update_ds, :no_key_update)
2141 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
2144 def for_share
2145   cached_lock_style_dataset(:_for_share_ds, :share)
2146 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
2167 def full_text_search(cols, terms, opts = OPTS)
2168   lang = Sequel.cast(opts[:language] || 'simple', :regconfig)
2169 
2170   unless opts[:tsvector]
2171     phrase_cols = full_text_string_join(cols)
2172     cols = Sequel.function(:to_tsvector, lang, phrase_cols)
2173   end
2174 
2175   unless opts[:tsquery]
2176     phrase_terms = terms.is_a?(Array) || terms.is_a?(Set) ? Sequel.array_or_set_join(terms, ' | ') : terms
2177 
2178     query_func = case to_tsquery = opts[:to_tsquery]
2179     when :phrase, :plain
2180       :"#{to_tsquery}to_tsquery"
2181     when :websearch
2182       :"websearch_to_tsquery"
2183     else
2184       (opts[:phrase] || opts[:plain]) ? :plainto_tsquery : :to_tsquery
2185     end
2186 
2187     terms = Sequel.function(query_func, lang, phrase_terms)
2188   end
2189 
2190   ds = where(Sequel.lit(["", " @@ ", ""], cols, terms))
2191 
2192   if opts[:phrase]
2193     raise Error, "can't use :phrase with either :tsvector or :tsquery arguments to full_text_search together" if opts[:tsvector] || opts[:tsquery]
2194     ds = ds.grep(phrase_cols, "%#{escape_like(phrase_terms)}%", :case_insensitive=>true)
2195   end
2196 
2197   if opts[:rank]
2198     ds = ds.reverse{ts_rank_cd(cols, terms)}
2199   end
2200 
2201   if opts[:headline]
2202     ds = ds.select_append{ts_headline(lang, phrase_cols, terms).as(:headline)}
2203   end
2204 
2205   ds
2206 end
insert(*values)

Insert given values into the database.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2209 def insert(*values)
2210   if @opts[:returning]
2211     # Already know which columns to return, let the standard code handle it
2212     super
2213   elsif @opts[:sql] || @opts[:disable_insert_returning]
2214     # Raw SQL used or RETURNING disabled, just use the default behavior
2215     # and return nil since sequence is not known.
2216     super
2217     nil
2218   else
2219     # Force the use of RETURNING with the primary key value,
2220     # unless it has been disabled.
2221     returning(insert_pk).insert(*values){|r| return r.values.first}
2222   end
2223 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
2260 def insert_conflict(opts=OPTS)
2261   clone(:insert_conflict => opts)
2262 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
2270 def insert_ignore
2271   insert_conflict
2272 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
2277 def insert_select(*values)
2278   return unless supports_insert_select?
2279   # Handle case where query does not return a row
2280   server?(:default).with_sql_first(insert_select_sql(*values)) || false
2281 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
2285 def insert_select_sql(*values)
2286   ds = opts[:returning] ? self : returning
2287   ds.insert_sql(*values)
2288 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
2292 def join_table(type, table, expr=nil, options=OPTS, &block)
2293   if expr.is_a?(SQL::AliasedExpression) && expr.expression.is_a?(Array) && !expr.expression.empty? && expr.expression.all?
2294     options = options.merge(:join_using=>true)
2295   end
2296   super
2297 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
2304 def lock(mode, opts=OPTS)
2305   if defined?(yield) # perform locking inside a transaction and yield to block
2306     @db.transaction(opts){lock(mode, opts); yield}
2307   else
2308     sql = 'LOCK TABLE '.dup
2309     source_list_append(sql, @opts[:from])
2310     mode = mode.to_s.upcase.strip
2311     unless LOCK_MODES.include?(mode)
2312       raise Error, "Unsupported lock mode: #{mode}"
2313     end
2314     sql << " IN #{mode} MODE"
2315     @db.execute(sql, opts)
2316   end
2317   nil
2318 end
merge(&block)

Support MERGE RETURNING on PostgreSQL 17+.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2321 def merge(&block)
2322   sql = merge_sql
2323   if uses_returning?(:merge)
2324     returning_fetch_rows(sql, &block)
2325   else
2326     execute_ddl(sql)
2327   end
2328 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
2339 def merge_delete_when_not_matched_by_source(&block)
2340   _merge_when(:type=>:delete_not_matched_by_source, &block)
2341 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
2352 def merge_do_nothing_when_matched(&block)
2353   _merge_when(:type=>:matched, &block)
2354 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
2365 def merge_do_nothing_when_not_matched(&block)
2366   _merge_when(:type=>:not_matched, &block)
2367 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
2378 def merge_do_nothing_when_not_matched_by_source(&block)
2379   _merge_when(:type=>:not_matched_by_source, &block)
2380 end
merge_insert(*values, &block)

Support OVERRIDING USER|SYSTEM VALUE for MERGE INSERT.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2383 def merge_insert(*values, &block)
2384   h = {:type=>:insert, :values=>values}
2385   if @opts[:override]
2386     h[:override] = insert_override_sql(String.new)
2387   end
2388   _merge_when(h, &block)
2389 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
2400 def merge_update_when_not_matched_by_source(values, &block)
2401   _merge_when(:type=>:update_not_matched_by_source, :values=>values, &block)
2402 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
2407 def overriding_system_value
2408   clone(:override=>:system)
2409 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
2413 def overriding_user_value
2414   clone(:override=>:user)
2415 end
supports_cte?(type=:select)
[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2417 def supports_cte?(type=:select)
2418   if type == :select
2419     server_version >= 80400
2420   else
2421     server_version >= 90100
2422   end
2423 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
2427 def supports_cte_in_subqueries?
2428   supports_cte?
2429 end
supports_distinct_on?()

DISTINCT ON is a PostgreSQL extension

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2432 def supports_distinct_on?
2433   true
2434 end
supports_group_cube?()

PostgreSQL 9.5+ supports GROUP CUBE

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2437 def supports_group_cube?
2438   server_version >= 90500
2439 end
supports_group_rollup?()

PostgreSQL 9.5+ supports GROUP ROLLUP

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2442 def supports_group_rollup?
2443   server_version >= 90500
2444 end
supports_grouping_sets?()

PostgreSQL 9.5+ supports GROUPING SETS

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2447 def supports_grouping_sets?
2448   server_version >= 90500
2449 end
supports_insert_conflict?()

PostgreSQL 9.5+ supports the ON CONFLICT clause to INSERT.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2457 def supports_insert_conflict?
2458   server_version >= 90500
2459 end
supports_insert_select?()

True unless insert returning has been disabled for this dataset.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2452 def supports_insert_select?
2453   !@opts[:disable_insert_returning]
2454 end
supports_lateral_subqueries?()

PostgreSQL 9.3+ supports lateral subqueries

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2462 def supports_lateral_subqueries?
2463   server_version >= 90300
2464 end
supports_merge?()

PostgreSQL 15+ supports MERGE.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2472 def supports_merge?
2473   server_version >= 150000
2474 end
supports_modifying_joins?()

PostgreSQL supports modifying joined datasets

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2467 def supports_modifying_joins?
2468   true
2469 end
supports_nowait?()

PostgreSQL supports NOWAIT.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2477 def supports_nowait?
2478   true
2479 end
supports_regexp?()

PostgreSQL supports pattern matching via regular expressions

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2492 def supports_regexp?
2493   true
2494 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
2483 def supports_returning?(type)
2484   if type == :merge
2485     server_version >= 170000
2486   else
2487     true
2488   end
2489 end
supports_skip_locked?()

PostgreSQL 9.5+ supports SKIP LOCKED.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2497 def supports_skip_locked?
2498   server_version >= 90500
2499 end
supports_timestamp_timezones?()

PostgreSQL supports timezones in literal timestamps

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2504 def supports_timestamp_timezones?
2505   # SEQUEL6: Remove
2506   true
2507 end
supports_window_clause?()

PostgreSQL 8.4+ supports WINDOW clause.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2511 def supports_window_clause?
2512   server_version >= 80400
2513 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
2522 def supports_window_function_frame_option?(option)
2523   case option
2524   when :rows, :range
2525     true
2526   when :offset
2527     server_version >= 90000
2528   when :groups, :exclude
2529     server_version >= 110000
2530   else
2531     false
2532   end
2533 end
supports_window_functions?()

PostgreSQL 8.4+ supports window functions

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2516 def supports_window_functions?
2517   server_version >= 80400
2518 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
2551 def truncate(opts = OPTS)
2552   if opts.empty?
2553     super()
2554   else
2555     clone(:truncate_opts=>opts).truncate
2556   end
2557 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
2562 def with_ties
2563   clone(:limit_with_ties=>true)
2564 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
2572 def _import(columns, values, opts=OPTS)
2573   if @opts[:returning]
2574     # no transaction: our multi_insert_sql_strategy should guarantee
2575     # that there's only ever a single statement.
2576     sql = multi_insert_sql(columns, values)[0]
2577     returning_fetch_rows(sql).map{|v| v.length == 1 ? v.values.first : v}
2578   elsif opts[:return] == :primary_key
2579     returning(insert_pk)._import(columns, values, opts)
2580   else
2581     super
2582   end
2583 end
to_prepared_statement(type, *a)
[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2585 def to_prepared_statement(type, *a)
2586   if type == :insert && !@opts.has_key?(:returning)
2587     returning(insert_pk).send(:to_prepared_statement, :insert_pk, *a)
2588   else
2589     super
2590   end
2591 end