Fixed joins as it was incorrectly duplicating the identity column.

Author: Altonymous

lib/active_record/connection_adapters/sqlserver/schema_statements.rb

@@ -190,10 +190,11 @@ def column_definitions(table_name)
               AND s.schema_id = s.schema_id
             INNER JOIN #{db_name_with_period}.sys.objects AS o
               ON s.schema_id = o.schema_id
-            INNER JOIN #{db_name_with_period}.sys.columns AS c
-              ON o.object_id = c.object_id
               AND o.is_ms_shipped = 0
               AND o.type = 'U'
+              AND o.name = columns.TABLE_NAME
+            INNER JOIN #{db_name_with_period}.sys.columns AS c
+              ON o.object_id = c.object_id
               AND c.name = columns.COLUMN_NAME
             WHERE columns.TABLE_NAME = @0
               AND columns.TABLE_SCHEMA = #{table_schema.blank? ? "schema_name()" : "@1"}