SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''=' ) LIMIT 1' at line 1
－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－－
这是什么原因啊