mysql存储过程写法—动态参数运用

        CREATE  PROCEDURE `up_common_select`
        (
         in t_name varchar(50)
        )
        begin
         declare v_sql varchar(500);
         set v_sql= concat('select * from ',t_name);
         select v_sql;

        --注意:prepare(预处理)execute stmt using @var,只能跟@var变量,declare和传入的变量不行!!!
         set @v_sql=v_sql;
         prepare stmt from @v_sql;
         EXECUTE stmt ;
         deallocate prepare stmt;
        end;