TabError: inconsistent use of tabs and spaces in indentation

Traceback (most recent call last):
  File "runweb.py", line 5, in <module>
    import db,util
  File "/home/roncoo-cmdb/devops/db.py", line 109
    sql = "SELECT %s FROM %s WHERE %s=%s" % (','.join(fields),table_name,k,v)	
                                                                             ^
TabError: inconsistent use of tabs and spaces in indentation
