Question

所以我必须根据某种类型查询数据库表，并且只想在1个查询中执行。以下是我想要合并的查询：

SELECT usr_id，SUM（币）AS coinppv FROM coin_tbl WHERE coin_type = 1 GROUP BY usr_id
SELECT usr_id，SUM（币）AS来自coin_tbl WHERE coin_type = 3 GROUP BY usr_id

然后我还希望获得coinppv和coinmly的总和，最后是GROUP BY usr_id。

我尝试过像ff这样的事情。但我没有得到我想要的结果：（注意：这个例子不包括总结coinppv和coinmly）

SELECT usr_id,
(SELECT SUM(coins) FROM `coin_tbl` WHERE coin_type = 1) AS coinppv,
(SELECT SUM(coins) FROM `coin_tbl` WHERE coin_type = 3) AS coinmly
FROM `coin_tbl` GROUP BY usr_id

我也参与了JOINing，但我也没有得到我想要的结果。

Answer 1

使用In

SELECT usr_id, SUM(coins) 
AS coinppv 
FROM coin_tbl
WHERE coin_type 
IN( 1,3) 
GROUP BY usr_id

Answer 2

SELECT usr_id, coin_type, SUM(coins)
FROM coin_tbl 
WHERE coin_type = 1 OR coin_type = 3 
GROUP BY usr_id, coin_type

在 SqlFiddle

上查看此操作

Swapnesh回答（一旦他将编辑它）更好，因为它使用IN子句更易读，如果你必须控制coin_type对“很多”不同类型（比如说五个）或六），但如果只涉及两个coin_type，则没有太大区别

Answer 3

SELECT usr_id,
       SUM(IF(coin_type = 1,coins,0)) AS coinppv,
       SUM(IF(coin_type = 3,coins,0)) AS coinmly, 
       SUM(coins) AS total
FROM `coin_tbl` 
WHERE coin_type IN (1,3)
GROUP BY usr_id

总数是类型1和3的总和，如果您需要全部

，请删除

Answer 4

如果你希望每个用户ID在一行中，那么这两个值都应该这样做

SELECT usr_id, SUM(if(coin_type = 1, coins, 0)) AS coinppv, SUM(if(coin_type = 3, coins, 0)) AS coinmly
FROM coin_tbl 
GROUP BY usr_id

如果您想将其作为JOIN进行，并假设您有一个用户表，则可以使用以下内容

SELECT usr_id, IFNULL(Sub1.coinppv, 0), IFNULL(Sub2.coinmly, 0)
FROM user_table 
LEFT OUTER JOIN (SELECT usr_id, SUM(coins) AS coinppv FROM `coin_tbl` WHERE coin_type = 1 GROUP BY usr_id) Sub1 ON coin_tbl.usr_id = Sub1.usr_id
LEFT OUTER JOIN (SELECT usr_id, SUM(coins) AS coinmly FROM `coin_tbl` WHERE coin_type = 3 GROUP BY usr_id) Sub2 ON coin_tbl.usr_id = Sub2.usr_id

MySQL 2查询组合成1个查询

4 个答案: