column_definition.rb in upsert-0.1.0

- old
+ new
@@ -1,20 +1,46 @@
 class Upsert
   class Buffer
     class PG_Connection < Buffer
+      # @private
+      # activerecord-3.2.5/lib/active_record/connection_adapters/postgresql_adapter.rb#column_definitions
       class ColumnDefinition
         class << self
+          def auto_increment_primary_key(connection, table_name)
+            res = connection.exec <<-EOS
+              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.refobjid      = '#{connection.quote_ident(table_name.to_s)}'::regclass
+EOS
+            if hit = res.first
+              hit['attname']
+            end
+          end
+
           def all(connection, table_name)
-            # activerecord-3.2.5/lib/active_record/connection_adapters/postgresql_adapter.rb#column_definitions
+            auto_increment_primary_key = auto_increment_primary_key(connection, table_name)
             res = connection.exec <<-EOS
 SELECT a.attname AS name, format_type(a.atttypid, a.atttypmod) AS sql_type, d.adsrc AS default
   FROM pg_attribute a LEFT JOIN pg_attrdef d
     ON a.attrelid = d.adrelid AND a.attnum = d.adnum
  WHERE a.attrelid = '#{connection.quote_ident(table_name.to_s)}'::regclass
    AND a.attnum > 0 AND NOT a.attisdropped
  ORDER BY a.attnum
  EOS
-            res.map do |row|
+            res.reject do |row|
+              row['name'] == auto_increment_primary_key
+            end.map do |row|
               new row['name'], row['sql_type'], row['default']
             end
           end
         end
 