BlogJava-梦在脚下-文章分类-mysql

update delete left join

追梦人 — Fri, 08 Apr 2011 11:42:00 GMT

delete c.* from drolecontest c left join drolebase d on d.rolebaseid=c.rolebaseid where d.rolelevel<16

update drolecontest c left join drolebase d on d.rolebaseid=c.rolebaseid set c.ranking=0,c.affluence=0 where d.rolelevel<=15

追梦人 2011-04-08 19:42 发表评论

procedure

追梦人 — Fri, 31 Dec 2010 04:37:00 GMT

create procedure pro_createcd()
begin
declare p_rolebaseid int;
-- 这个用于处理游标到达最后一行的情况
    declare stop int default 0;
    -- 声明游标
    declare cur cursor for select rolebaseid from drolecoolteam group by rolebaseid;
-- 打开游标
    open cur;

    -- 读取一行数据到变量
    fetch cur into p_rolebaseid;
    -- 这个就是判断是否游标已经到达了最后
    while stop <> 1 do
insert into drolecoolteam(rolebaseid,coolid,cooltype,cooltime) values(p_rolebaseid,0,15,0);
        fetch cur into p_rolebaseid;
    end while; -- 循环结束
    close cur; -- 关闭游标
end

追梦人 2010-12-31 12:37 发表评论

MYSQL 时间差秒数

追梦人 — Wed, 29 Dec 2010 03:11:00 GMT

SELECT ( UNIX_TIMESTAMP(now()) - UNIX_TIMESTAMP(recoverytime) ) from drolestate;

追梦人 2010-12-29 11:11 发表评论

mysql里的判断，截取

追梦人 — Tue, 23 Mar 2010 08:08:00 GMT

select dr.name, round(sum(dr.killed)/((case sum(dr.deaded) when 0 then 1 else sum(dr.deaded) end)), 2) ,round(avg(dr.assists), 2) from dota dr where dr.type=3 group by dr.name

case sum(dr.deaded) when 0 then 1 else sum(dr.deaded) end 当sum(dr.deaded)为0时取1，否则取本身

追梦人 2010-03-23 16:08 发表评论

好用的mysql?

追梦人 — Wed, 10 Feb 2010 02:30:00 GMT

update dotarank as dr left join ((select * from dotarank where `type`=2) as d) on dr.name=d.name set dr.assistschange=dr.assists-d.assists where dr.`type`=3;

mysql关键字用tab上面那个符号排除

追梦人 2010-02-10 10:30 发表评论