module Sequel::Postgres::DatasetMethods

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

Constants

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
1839 def analyze
1840   explain(:analyze=>true)
1841 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
1846 def complex_expression_sql_append(sql, op, args)
1847   case op
1848   when :^
1849     j = ' # '
1850     c = false
1851     args.each do |a|
1852       sql << j if c
1853       literal_append(sql, a)
1854       c ||= true
1855     end
1856   when :ILIKE, :'NOT ILIKE'
1857     sql << '('
1858     literal_append(sql, args[0])
1859     sql << ' ' << op.to_s << ' '
1860     literal_append(sql, args[1])
1861     sql << ')'
1862   else
1863     super
1864   end
1865 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
1881 def disable_insert_returning
1882   clone(:disable_insert_returning=>true)
1883 end
empty?()

Always return false when using VALUES

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
1886 def empty?
1887   return false if @opts[:values]
1888   super
1889 end
explain(opts=OPTS)

Return the results of an EXPLAIN query as a string

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
1892 def explain(opts=OPTS)
1893   with_sql((opts[:analyze] ? 'EXPLAIN ANALYZE ' : 'EXPLAIN ') + select_sql).map(:'QUERY PLAN').join("\r\n")
1894 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
1897 def for_share
1898   lock_style(:share)
1899 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
1920 def full_text_search(cols, terms, opts = OPTS)
1921   lang = Sequel.cast(opts[:language] || 'simple', :regconfig)
1922 
1923   unless opts[:tsvector]
1924     phrase_cols = full_text_string_join(cols)
1925     cols = Sequel.function(:to_tsvector, lang, phrase_cols)
1926   end
1927 
1928   unless opts[:tsquery]
1929     phrase_terms = terms.is_a?(Array) ? terms.join(' | ') : terms
1930 
1931     query_func = case to_tsquery = opts[:to_tsquery]
1932     when :phrase, :plain
1933       :"#{to_tsquery}to_tsquery"
1934     when :websearch
1935       :"websearch_to_tsquery"
1936     else
1937       (opts[:phrase] || opts[:plain]) ? :plainto_tsquery : :to_tsquery
1938     end
1939 
1940     terms = Sequel.function(query_func, lang, phrase_terms)
1941   end
1942 
1943   ds = where(Sequel.lit(["", " @@ ", ""], cols, terms))
1944 
1945   if opts[:phrase]
1946     raise Error, "can't use :phrase with either :tsvector or :tsquery arguments to full_text_search together" if opts[:tsvector] || opts[:tsquery]
1947     ds = ds.grep(phrase_cols, "%#{escape_like(phrase_terms)}%", :case_insensitive=>true)
1948   end
1949 
1950   if opts[:rank]
1951     ds = ds.reverse{ts_rank_cd(cols, terms)}
1952   end
1953 
1954   if opts[:headline]
1955     ds = ds.select_append{ts_headline(lang, phrase_cols, terms).as(:headline)}
1956   end
1957 
1958   ds
1959 end
insert(*values)

Insert given values into the database.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
1962 def insert(*values)
1963   if @opts[:returning]
1964     # Already know which columns to return, let the standard code handle it
1965     super
1966   elsif @opts[:sql] || @opts[:disable_insert_returning]
1967     # Raw SQL used or RETURNING disabled, just use the default behavior
1968     # and return nil since sequence is not known.
1969     super
1970     nil
1971   else
1972     # Force the use of RETURNING with the primary key value,
1973     # unless it has been disabled.
1974     returning(insert_pk).insert(*values){|r| return r.values.first}
1975   end
1976 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
2013 def insert_conflict(opts=OPTS)
2014   clone(:insert_conflict => opts)
2015 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
2023 def insert_ignore
2024   insert_conflict
2025 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
2030 def insert_select(*values)
2031   return unless supports_insert_select?
2032   # Handle case where query does not return a row
2033   server?(:default).with_sql_first(insert_select_sql(*values)) || false
2034 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
2038 def insert_select_sql(*values)
2039   ds = opts[:returning] ? self : returning
2040   ds.insert_sql(*values)
2041 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
2045 def join_table(type, table, expr=nil, options=OPTS, &block)
2046   if expr.is_a?(SQL::AliasedExpression) && expr.expression.is_a?(Array) && !expr.expression.empty? && expr.expression.all?
2047     options = options.merge(:join_using=>true)
2048   end
2049   super
2050 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
2057 def lock(mode, opts=OPTS)
2058   if defined?(yield) # perform locking inside a transaction and yield to block
2059     @db.transaction(opts){lock(mode, opts); yield}
2060   else
2061     sql = 'LOCK TABLE '.dup
2062     source_list_append(sql, @opts[:from])
2063     mode = mode.to_s.upcase.strip
2064     unless LOCK_MODES.include?(mode)
2065       raise Error, "Unsupported lock mode: #{mode}"
2066     end
2067     sql << " IN #{mode} MODE"
2068     @db.execute(sql, opts)
2069   end
2070   nil
2071 end
merge(&block)

Support MERGE RETURNING on PostgreSQL 17+.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2074 def merge(&block)
2075   sql = merge_sql
2076   if uses_returning?(:merge)
2077     returning_fetch_rows(sql, &block)
2078   else
2079     execute_ddl(sql)
2080   end
2081 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
2092 def merge_delete_when_not_matched_by_source(&block)
2093   _merge_when(:type=>:delete_not_matched_by_source, &block)
2094 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
2105 def merge_do_nothing_when_matched(&block)
2106   _merge_when(:type=>:matched, &block)
2107 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
2118 def merge_do_nothing_when_not_matched(&block)
2119   _merge_when(:type=>:not_matched, &block)
2120 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
2131 def merge_do_nothing_when_not_matched_by_source(&block)
2132   _merge_when(:type=>:not_matched_by_source, &block)
2133 end
merge_insert(*values, &block)

Support OVERRIDING USER|SYSTEM VALUE for MERGE INSERT.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2136 def merge_insert(*values, &block)
2137   h = {:type=>:insert, :values=>values}
2138   if @opts[:override]
2139     h[:override] = insert_override_sql(String.new)
2140   end
2141   _merge_when(h, &block)
2142 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
2153 def merge_update_when_not_matched_by_source(values, &block)
2154   _merge_when(:type=>:update_not_matched_by_source, :values=>values, &block)
2155 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
2160 def overriding_system_value
2161   clone(:override=>:system)
2162 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
2166 def overriding_user_value
2167   clone(:override=>:user)
2168 end
supports_cte?(type=:select)
[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2170 def supports_cte?(type=:select)
2171   if type == :select
2172     server_version >= 80400
2173   else
2174     server_version >= 90100
2175   end
2176 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
2180 def supports_cte_in_subqueries?
2181   supports_cte?
2182 end
supports_distinct_on?()

DISTINCT ON is a PostgreSQL extension

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2185 def supports_distinct_on?
2186   true
2187 end
supports_group_cube?()

PostgreSQL 9.5+ supports GROUP CUBE

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2190 def supports_group_cube?
2191   server_version >= 90500
2192 end
supports_group_rollup?()

PostgreSQL 9.5+ supports GROUP ROLLUP

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2195 def supports_group_rollup?
2196   server_version >= 90500
2197 end
supports_grouping_sets?()

PostgreSQL 9.5+ supports GROUPING SETS

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2200 def supports_grouping_sets?
2201   server_version >= 90500
2202 end
supports_insert_conflict?()

PostgreSQL 9.5+ supports the ON CONFLICT clause to INSERT.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2210 def supports_insert_conflict?
2211   server_version >= 90500
2212 end
supports_insert_select?()

True unless insert returning has been disabled for this dataset.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2205 def supports_insert_select?
2206   !@opts[:disable_insert_returning]
2207 end
supports_lateral_subqueries?()

PostgreSQL 9.3+ supports lateral subqueries

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2215 def supports_lateral_subqueries?
2216   server_version >= 90300
2217 end
supports_merge?()

PostgreSQL 15+ supports MERGE.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2225 def supports_merge?
2226   server_version >= 150000
2227 end
supports_modifying_joins?()

PostgreSQL supports modifying joined datasets

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2220 def supports_modifying_joins?
2221   true
2222 end
supports_nowait?()

PostgreSQL supports NOWAIT.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2230 def supports_nowait?
2231   true
2232 end
supports_regexp?()

PostgreSQL supports pattern matching via regular expressions

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2245 def supports_regexp?
2246   true
2247 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
2236 def supports_returning?(type)
2237   if type == :merge
2238     server_version >= 170000
2239   else
2240     true
2241   end
2242 end
supports_skip_locked?()

PostgreSQL 9.5+ supports SKIP LOCKED.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2250 def supports_skip_locked?
2251   server_version >= 90500
2252 end
supports_timestamp_timezones?()

PostgreSQL supports timezones in literal timestamps

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2257 def supports_timestamp_timezones?
2258   # SEQUEL6: Remove
2259   true
2260 end
supports_window_clause?()

PostgreSQL 8.4+ supports WINDOW clause.

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2264 def supports_window_clause?
2265   server_version >= 80400
2266 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
2275 def supports_window_function_frame_option?(option)
2276   case option
2277   when :rows, :range
2278     true
2279   when :offset
2280     server_version >= 90000
2281   when :groups, :exclude
2282     server_version >= 110000
2283   else
2284     false
2285   end
2286 end
supports_window_functions?()

PostgreSQL 8.4+ supports window functions

[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2269 def supports_window_functions?
2270   server_version >= 80400
2271 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
2304 def truncate(opts = OPTS)
2305   if opts.empty?
2306     super()
2307   else
2308     clone(:truncate_opts=>opts).truncate
2309   end
2310 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
2315 def with_ties
2316   clone(:limit_with_ties=>true)
2317 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
2325 def _import(columns, values, opts=OPTS)
2326   if @opts[:returning]
2327     # no transaction: our multi_insert_sql_strategy should guarantee
2328     # that there's only ever a single statement.
2329     sql = multi_insert_sql(columns, values)[0]
2330     returning_fetch_rows(sql).map{|v| v.length == 1 ? v.values.first : v}
2331   elsif opts[:return] == :primary_key
2332     returning(insert_pk)._import(columns, values, opts)
2333   else
2334     super
2335   end
2336 end
to_prepared_statement(type, *a)
[show source] 
     # File lib/sequel/adapters/shared/postgres.rb
2338 def to_prepared_statement(type, *a)
2339   if type == :insert && !@opts.has_key?(:returning)
2340     returning(insert_pk).send(:to_prepared_statement, :insert_pk, *a)
2341   else
2342     super
2343   end
2344 end