diff options
Diffstat (limited to 'activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb')
-rw-r--r-- | activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb | 24 |
1 files changed, 13 insertions, 11 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb index 69aa02ccf4..04b1cc479f 100644 --- a/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb +++ b/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb @@ -353,17 +353,19 @@ module ActiveRecord nil end - # Returns just a table's primary key - def primary_key(table) - pks = query(<<-end_sql, 'SCHEMA') - SELECT attr.attname - FROM pg_attribute attr - INNER JOIN pg_constraint cons ON attr.attrelid = cons.conrelid AND attr.attnum = any(cons.conkey) - WHERE cons.contype = 'p' - AND cons.conrelid = '#{quote_table_name(table)}'::regclass - end_sql - return nil unless pks.count == 1 - pks[0][0] + def primary_keys(table_name) # :nodoc: + select_values(<<-SQL.strip_heredoc, 'SCHEMA') + WITH pk_constraint AS ( + SELECT conrelid, unnest(conkey) AS connum FROM pg_constraint + WHERE contype = 'p' + AND conrelid = '#{quote_table_name(table_name)}'::regclass + ), cons AS ( + SELECT conrelid, connum, row_number() OVER() AS rownum FROM pk_constraint + ) + SELECT attr.attname FROM pg_attribute attr + INNER JOIN cons ON attr.attrelid = cons.conrelid AND attr.attnum = cons.connum + ORDER BY cons.rownum + SQL end # Renames a table. |