mYSQL存储过程的错误: 存储过程如下: create procedure mypo02(in DataName varchar(10)) begin if DataName is null or DataName = "" then select * from ssd; else select * from ssd where ename like concat('%',DataName,'%'); end if; end; 报错:Procedure execution failed 1054 - Unknown column '王小李' in 'field list' 只要传值进去就报字段不在列表中,当我把 DataName 改成int 整型的时候运行可以,当为字符串运行就报错。请教高手要这么处理?