Fixed #350 -- 'offset' DB API parameter now works in MySQL 3. Tests from [540] pass. Thanks, ronan@cremin.com

git-svn-id: http://code.djangoproject.com/svn/django/trunk@541 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/core/db/__init__.py

@@ -37,6 +37,7 @@ dictfetchall = dbmod.dictfetchall
 get_last_insert_id = dbmod.get_last_insert_id
 get_date_extract_sql = dbmod.get_date_extract_sql
 get_date_trunc_sql = dbmod.get_date_trunc_sql
+get_limit_offset_sql = dbmod.get_limit_offset_sql
 get_table_list = dbmod.get_table_list
 get_relations = dbmod.get_relations
 OPERATOR_MAPPING = dbmod.OPERATOR_MAPPING

django/core/db/backends/mysql.py

@@ -71,6 +71,12 @@ def get_date_trunc_sql(lookup_type, field_name):
         subtractions.append(" - interval (DATE_FORMAT(%s, '%%%%m')-1) month" % field_name)
     return "(%s - %s)" % (field_name, ''.join(subtractions))
 
+def get_limit_offset_sql(limit, offset=None):
+    sql = "LIMIT "
+    if offset and offset != 0:
+        sql += "%s," % offset
+    return sql + str(limit)
+
 def get_table_list(cursor):
     "Returns a list of table names in the current database."
     cursor.execute("SHOW TABLES")

django/core/db/backends/postgresql.py

@@ -71,6 +71,12 @@ def get_date_trunc_sql(lookup_type, field_name):
     # http://www.postgresql.org/docs/8.0/static/functions-datetime.html#FUNCTIONS-DATETIME-TRUNC
     return "DATE_TRUNC('%s', %s)" % (lookup_type, field_name)
 
+def get_limit_offset_sql(limit, offset=None):
+    sql = "LIMIT %s" % limit
+    if offset and offset != 0:
+        sql += " OFFSET %s" % offset
+    return sql
+
 def get_table_list(cursor):
     "Returns a list of table names in the current database."
     cursor.execute("""

django/core/db/backends/sqlite3.py

@@ -97,6 +97,12 @@ def get_date_trunc_sql(lookup_type, field_name):
     # sqlite doesn't support DATE_TRUNC, so we fake it as above.
     return 'django_date_trunc("%s", %s)' % (lookup_type.lower(), field_name)
 
+def get_limit_offset_sql(limit, offset=None):
+    sql = "LIMIT %s" % limit
+    if offset and offset != 0:
+        sql += " OFFSET %s" % offset
+    return sql
+
 def _sqlite_date_trunc(lookup_type, dt):
     try:
         dt = typecasts.typecast_timestamp(dt)

django/core/meta/__init__.py

@@ -1277,10 +1277,9 @@ def function_get_sql_clause(opts, **kwargs):
 
     # LIMIT and OFFSET clauses
     if kwargs.get('limit') is not None:
-        limit_sql = " LIMIT %s " % kwargs['limit']
+        limit_sql = " %s " % db.get_limit_offset_sql(kwargs['limit'], kwargs.get('offset'))
-        if kwargs.get('offset') is not None and kwargs['offset'] != 0:
-            limit_sql += "OFFSET %s " % kwargs['offset']
     else:
+        assert kwargs.get('offset') is None, "'offset' is not allowed without 'limit'"
         limit_sql = ""
 
     return select, " FROM " + ",".join(tables) + (where and " WHERE " + " AND ".join(where) or "") + (order_by and " ORDER BY " + order_by or "") + limit_sql, params