选择总和并按种类分组

Question

我试图用MySql数据库中的数据填充Morris图表的数据数组。

我有这样的表“ buchungen”：

ID   Value   Kind   Date
1    200     L      2016-01-01
2    250     B      2016-01-01
3    250     L      2016-01-01
4    200     B      2016-02-01
5    250     B      2016-02-01
6    200     L      2016-02-01

我想做一个查询，给我这样的输出：

价值总和，按数据和种类分组。

一月份：450，L和250 B

2月：450 B和200 L

所需的结构：

[{"m":"1","a":"450","b":"250},{"m":"2","a":"200","b":"450}]

用我的查询：

SELECT MONTH( date ) AS m, SUM( value ) AS a
FROM  `buchungen`
WHERE YEAR( date ) = YEAR( CURDATE( ) )
GROUP BY MONTH( date )

我得到以下结构：

[{"m":"4","a":"476852.64"},{"m":"5","a":"851866.74"}]

我有一个我不知道如何考虑“种类”领域的问题。 我怎样才能做到这一点？

谢谢！

Answer 1

尝试这个：

SELECT MONTH( date ) AS m, 
       SUM(CASE WHEN Kind = 'L' THEN value ELSE 0 END) AS a,
       SUM(CASE WHEN Kind = 'B' THEN value ELSE 0 END) AS b
FROM  `buchungen`
WHERE YEAR( date ) = YEAR( CURDATE( ) )
GROUP BY MONTH( date )

Answer 2

如前所述，您想要按日期和种类分组的值总和，请尝试以下操作：

SELECT MONTH( date ) AS m, kind, SUM( value ) AS a FROM  `buchungen` WHERE YEAR( date ) = YEAR( CURDATE( ) ) GROUP BY MONTH( date ), kind;