Question

我需要一个查询，该查询根据一列返回四个不同的总和，但不知道如何在没有子查询的情况下进行操作。

基本上我需要做的是：我有两个表，“ caixa”和“ movimentacao”。表“ movimentacao”具有一个字段“ type”（范围从0到3）和一个字段“ value”，并且需要一个查询，该查询返回属于“ caixa”的每种“ movimentacao”类型的值之和，但只能排成一行，因此按类型分组是行不通的。

到目前为止，我的解决方案是：

SELECT
    (SELECT SUM(value) FROM movimentacao where id_caixa = x.id_caixa and type = 0)
    (SELECT SUM(value) FROM movimentacao where id_caixa = x.id_caixa and type = 1)
    (SELECT SUM(value) FROM movimentacao where id_caixa = x.id_caixa and type = 2)
    (SELECT SUM(value) FROM movimentacao where id_caixa = x.id_caixa and type = 3)
FROM caixa x

是否有一种方法可以在没有这四个子查询的情况下使用联接代替呢？

Answer 1

您可以使用聚合来实现：

SELECT SUM( CASE WHEN m.type = 0 THEN x.value END ) as type_0,
       SUM( CASE WHEN m.type = 1 THEN x.value  END ) as type_1,
       SUM( CASE WHEN m.type = 2 THEN x.value  END ) as type_2,
       SUM( CASE WHEN m.type = 3 THEN x.value  END ) as type_3
FROM caixa x JOIN
     movimentacao m
     ON x.id_caixa = m.id_caixa;

Answer 2

您可以执行多个OR

SELECT SUM(value) FROM movimentacao where id_caixa = x.id_caixa and type = 0 or type = 1 or type = 3

或使用BETWEEN

SELECT SUM(value) FROM movimentacao where id_caixa = x.id_caixa and type BETWEEN 0 AND 3

如何在没有子查询的情况下在一行中进行多个总和的查询？

2 个答案: