better get_table_columns

oml/db.py

@@ -95,7 +95,8 @@ def get_create_table(table):
 
 def get_table_columns(table):
     create_table = get_create_table(table)
-    columns = [r.strip().split()[0] for r in re.compile('(.*?),').findall(create_table)][:-1]
+    columns = create_table.split('(', 1)[1].rsplit(')', 1)[0]
+    columns = [r.strip().split()[0] for r in re.compile('(.*?),').findall(columns)]
     columns = [col for col in columns if col.islower()]
     return columns