Question

如何在没有分组的情况下获得结果？

我的表

id  user_id amount  currency_id type    status
5   2   2.00    1   0   0
6   3   3.00    1   0   0
4   1   1.00    1   0   0
7   4   4.00    1   0   0
8   5   3.00    1   1   0

我执行以下选择

SELECT id, user_id, amount, currency_id, SUM( amount ) 
FROM market
WHERE amount <=3
AND type = 0
AND status = 0

结果：

id  user_id amount  currency_id SUM( amount )
5   2   2.00    1   6.00

如何得到这个结果：

id  user_id amount  currency_id SUM( amount )
5   2   2.00    1   0   6.00
6   3   3.00    1   0   6.00
4   1   1.00    1   0   6.00

Answer 1

你可以加入

SELECT  id, 
        user_id, 
        amount, 
        currency_id, 
        a.totalAmount
FROM    market
        CROSS JOIN
        (
            SELECT SUM(amount) totalAmount
            FROM    market
            WHERE   amount <=3
                    AND type = 0 
                    AND status = 0
        ) a
WHERE   amount <=3
        AND type = 0 
        AND status = 0

或使用内联子查询，

SELECT  id, 
        user_id, 
        amount, 
        currency_id, 
        (
            SELECT SUM(amount) totalAmount
            FROM    market
            WHERE   amount <=3
                    AND type = 0 
                    AND status = 0
        ) totalAmount
FROM    market
WHERE   amount <=3
        AND type = 0 
        AND status = 0

Answer 2

如果您的目的是返回符合此条件的单个记录并总结它们，并且您实际上并不需要将SUM值作为每行的字段（不确定为什么会这样），那么我建议您在GROUP BY ... WITH ROLLUP修饰符处。它的工作原理如下：

SELECT id, user_id, SUM(amount) AS `amounts`, currency_id
FROM market
WHERE amount <=3
AND type = 0
AND status = 0
GROUP BY id WITH ROLLUP

这里我按id进行分组，因为这会使各个记录保持不变，因为此值是唯一的

您的输出将如下所示：

id    user_id amounts  currency_id
5     2       2.00    1
6     3       3.00    1
4     1       1.00    1
NULL  3       6.00    1

请注意，最后一条记录提供了SUM()功能的汇总。另请注意，汇总行中user_id和currency_id的值是不确定的，因为它们不是GROUP BY或聚合的一部分。因此，它们毫无意义。

Answer 3

你走了：

SELECT id, user_id, amount, currency_id, t2.total
FROM market, (
    SELECT SUM(amount) AS total
    FROM market
    WHERE amount <=3
    AND type = 0
    AND status = 0
) AS t2
WHERE amount <=3
AND type = 0
AND status = 0

没有分组的SELECT

3 个答案: