[英]Mysql - calculate difference between two columns in 2 different tables and insert
我有以下语句,该语句需要再添加1个子查询以计算tweeps
表中的关注者数量与ranking
表中当前列的数量之间的差,并在ranking
表中latest
列中插入差异,以确保PK为屏幕名称 ,
像tweeps表中跟随者coulm中的数字是10当前coulmn n排名表,相同的屏幕名称是5,该值将被添加到最新的+5
mysql_query ("
INSERT INTO ranking
SELECT @rank := @rank + 1, tweeps.* FROM tweeps
JOIN( SELECT @rank := 0 ) AS init
ORDER BY followers DESC
ON DUPLICATE KEY UPDATE
ranking.ranking = @rank,
ranking.name = tweeps.name,
ranking.followers = tweeps.followers,
ranking.tweets = tweeps.tweets,
ranking.location = tweeps.location,
ranking.`join date` = tweeps.join_date,
ranking.avatar = tweeps.avatar;");
mysql_close($con);
尝试这个:
INSERT INTO ranking
SELECT @rank := @rank + 1, tweeps.* FROM tweeps
JOIN( SELECT @rank := 0 ) AS init
ORDER BY followers DESC
ON DUPLICATE KEY
UPDATE ranking set
ranking = @rank,
name = tweeps.name,
followers = tweeps.followers - followers,
tweets = tweeps.tweets,
location = tweeps.location,
`join date` = tweeps.join_date,
avatar = tweeps.avatar;
我将语法更改为ON DUPLICATE KEY UPDATE ranking set...
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