mysql 将表名当做参数传给存储过程

参考： http://blog.csdn.net/chszs/article/details/5818363

drop procedure if exists `simpleproc`;

delimiter //
CREATE PROCEDURE `simpleproc`(in tname varchar(128), in days int, out tt datetime)
begin
    set @sqlcmd = concat('select max(start_date_time) into @tmp from ', tname);
    prepare stmt from @sqlcmd;
    execute stmt;
    deallocate prepare stmt;
    set @tmp=date(@tmp);
    set @tmp=date_sub(@tmp, interval days day);
    set tt=timestamp(@tmp);
end//

delimiter ;
call simpleproc('gb_kpi_service', 7, @tt);