MySQL存储过程获取记录排名代码,MYSQL代码库,德仔网

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【MYSQL】 MySQL存储过程获取记录排名

作者:xialeistudio / 发布于2014/4/8/ 1379

MySQL存储过程获取记录排名（一般用于投票系统）

//MySQL存储过程获取记录排名（一般用于投票系统）
//原理
//计算当前学校的票数，暂且记作a
//计算票数大于自己的学校数目，暂且记作b，如果b=0，则自己票数排名第一
//计算票数小于自己的学校数目，暂且记作c，如果c=0，则自己票数排名最后
//如果b != 0 && c != 0，那么b+c就是自己的票数排名



CREATE PROCEDURE `get_rank`(IN `school` INT)
BEGIN
SET @votes = (SELECT COUNT(tcl_vote.vote_id) AS counts FROM tcl_works LEFT JOIN tcl_vote ON tcl_vote.works_id = tcl_works.works_id WHERE tcl_works.school_id=school);
SET @gt = (
SELECT
COUNT(*)
FROM
(
SELECT
tcl_works.school_id,
COUNT(tcl_vote.vote_id) AS votes
FROM
tcl_works
LEFT JOIN tcl_vote ON tcl_vote.works_id = tcl_works.works_id
GROUP BY
tcl_works.school_id
HAVING
votes &gt; @votes
ORDER BY
votes DESC
)
AS xxx
);
IF @gt = 0
THEN
SET @rank = 1;
SELECT @rank AS rank;
ELSE
SET @lt = (
SELECT
COUNT(*)
FROM
(
SELECT
tcl_works.school_id,
COUNT(tcl_vote.vote_id) AS votes
FROM
tcl_works
LEFT JOIN tcl_vote ON tcl_vote.works_id = tcl_works.works_id
GROUP BY
tcl_works.school_id
HAVING
votes &lt; @votes
ORDER BY
votes DESC
)
AS xxx
);
IF @lt = 0
THEN
SET @rank =(SELECT COUNT(*) FROM tcl_school LIMIT 1);
SELECT @rank AS rank;
ELSE
SET @rank = (@gt+@lt);
SELECT @rank AS rank;
END IF;
END IF;
END;

call get_rank(1)

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