From 486a890505e268ddbc37edf7f1b32fbebd337fc1 Mon Sep 17 00:00:00 2001 From: Akira Matsuda Date: Wed, 18 May 2011 18:31:34 +0900 Subject: why not use JOIN statement for joining tables? (vol. 2) --- .../connection_adapters/postgresql_adapter.rb | 33 ++++++++-------------- 1 file changed, 12 insertions(+), 21 deletions(-) diff --git a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb index 196e5630ae..4c3fcfc70e 100644 --- a/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb +++ b/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb @@ -820,18 +820,13 @@ module ActiveRecord # given table's primary key. result = exec_query(<<-end_sql, 'SCHEMA').rows.first SELECT attr.attname, seq.relname - FROM pg_class seq, - pg_attribute attr, - pg_depend dep, - pg_constraint cons - WHERE seq.oid = dep.objid - AND seq.relkind = 'S' - AND attr.attrelid = dep.refobjid - AND attr.attnum = dep.refobjsubid - AND attr.attrelid = cons.conrelid - AND attr.attnum = cons.conkey[1] - AND cons.contype = 'p' - AND dep.refobjid = '#{quote_table_name(table)}'::regclass + FROM pg_class seq + INNER JOIN pg_depend dep on seq.oid = dep.objid + INNER JOIN pg_attribute attr ON attr.attrelid = dep.refobjid AND attr.attnum = dep.refobjsubid + INNER JOIN pg_constraint cons ON attr.attrelid = cons.conrelid AND attr.attnum = cons.conkey[1] + WHERE seq.relkind = 'S' + AND cons.contype = 'p' + AND dep.refobjid = '#{quote_table_name(table)}'::regclass end_sql # [primary_key, sequence] @@ -844,15 +839,11 @@ module ActiveRecord def primary_key(table) row = exec_query(<<-end_sql, 'SCHEMA', [[nil, table]]).rows.first SELECT DISTINCT(attr.attname) - FROM pg_attribute attr, - pg_depend dep, - pg_constraint cons - WHERE attr.attrelid = dep.refobjid - AND attr.attnum = dep.refobjsubid - AND attr.attrelid = cons.conrelid - AND attr.attnum = cons.conkey[1] - AND cons.contype = 'p' - AND dep.refobjid = $1::regclass + FROM pg_attribute attr + INNER JOIN pg_depend dep ON attr.attrelid = dep.refobjid AND attr.attnum = dep.refobjsubid + INNER JOIN pg_constraint cons ON attr.attrelid = cons.conrelid AND attr.attnum = cons.conkey[1] + WHERE cons.contype = 'p' + AND dep.refobjid = $1::regclass end_sql row && row.first -- cgit v1.2.3