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[rails.git] / config / initializers / postgresql_adapter.rb

diff --git a/config/initializers/postgresql_adapter.rb b/config/initializers/postgresql_adapter.rb
index 0420a7495896ba1eff779f36d8438bcbc94f4316..75971e4bf115980f294c7e591b299a8434c7591b 100644 (file)
--- a/config/initializers/postgresql_adapter.rb
+++ b/config/initializers/postgresql_adapter.rb
@@ -1,32 +1,62 @@
-module ActiveRecord
-  module ConnectionAdapters
-    class PostgreSQLAdapter
-      alias_method :old_pk_and_sequence_for, :pk_and_sequence_for
-
-      def pk_and_sequence_for(table)
-        result = query(<<-end_sql, 'PK and serial sequence')[0]
-          SELECT attr.attname, seq.relname
-          FROM pg_class      seq,
-               pg_attribute  attr,
-               pg_depend     dep,
-               pg_namespace  name,
-               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.classid       = '"pg_class"'::regclass
-            AND dep.refclassid    = '"pg_class"'::regclass
-            AND dep.refobjid      = '#{quote_table_name(table)}'::regclass
-        end_sql
+if defined?(ActiveRecord::ConnectionAdapters::PostgreSQLAdapter)
+  module ActiveRecord
+    module ConnectionAdapters
+      class PostgreSQLAdapter
+        def supports_disable_referential_integrity?() #:nodoc:
+          version = query("SHOW server_version")[0][0].split('.')
+          (version[0].to_i >= 9 || (version[0].to_i == 8 && version[1].to_i >= 1)) ? true : false
+        rescue
+          return false
+        end
 
-        if result.nil? or result.empty?
-          old_pk_and_sequence_for(table)
-        else
+        def pk_and_sequence_for(table)
+          # First try looking for a sequence with a dependency on the
+          # given table's primary key.
+          result = query(<<-end_sql, 'PK and serial sequence')[0]
+            SELECT attr.attname, seq.relname
+            FROM pg_class      seq,
+                 pg_attribute  attr,
+                 pg_depend     dep,
+                 pg_namespace  name,
+                 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.classid       = '"pg_class"'::regclass
+              AND dep.refclassid    = '"pg_class"'::regclass
+              AND dep.refobjid      = '#{quote_table_name(table)}'::regclass
+          end_sql
+  
+          if result.nil? or result.empty?
+            # If that fails, try parsing the primary key's default value.
+            # Support the 7.x and 8.0 nextval('foo'::text) as well as
+            # the 8.1+ nextval('foo'::regclass).
+            result = query(<<-end_sql, 'PK and custom sequence')[0]
+              SELECT attr.attname,
+                CASE
+                  WHEN split_part(def.adsrc, '''', 2) ~ '.' THEN
+                    substr(split_part(def.adsrc, '''', 2),
+                           strpos(split_part(def.adsrc, '''', 2), '.')+1)
+                  ELSE split_part(def.adsrc, '''', 2)
+                END
+              FROM pg_class       t
+              JOIN pg_attribute   attr ON (t.oid = attrelid)
+              JOIN pg_attrdef     def  ON (adrelid = attrelid AND adnum = attnum)
+              JOIN pg_constraint  cons ON (conrelid = adrelid AND adnum = conkey[1])
+              WHERE t.oid = '#{quote_table_name(table)}'::regclass
+                AND cons.contype = 'p'
+                AND def.adsrc ~* 'nextval'
+            end_sql
+          end
+  
+          # [primary_key, sequence]
           [result.first, result.last]
+        rescue
+          nil
         end
       end
     end