Question

可能是重复的问题，但我的问题不是解决。

我正在尝试使用日期确定项目的内向和外向
表。

在表1中，我们将其简称为A_Dt。我会有三列即A_Na，A_Qty，B_Dt

在表2中，我们将其简称为“B”。我会有三列，即B_N，B_Qty a，C_Dt

在表3中，我们将其简称为“C”。我会有三列，即C_N，C_Qty a，

Table :A

    A_Dt         A_Na  A_Qty
    2016-08-01    XY     50
    2016-08-02    XY     100
    2016-08-05    XY     150

表A和B是向内的，C是向外的。
我使用了修改后的查询，但添加了第三列。

表格示例：

B_Dt       B_Na  B_Qty
2016-08-01  XY  150
2016-08-03  XY  100
2016-08-04  XY  200

表B：

C_Dt       C_Na  C_Qty
2016-08-01  XY  150
2016-08-03  XY  100
2016-08-04  XY  200

表C：

Date           Inward   Outward
2016-08-01      200      150
2016-08-02      100      0
2016-08-03      100      100
2016-08-04      200      200
2016-08-05      150      0

预期产出

select t.Dt as Date, sum(t.Qty) as Inward,sum(t.outward) as outward1 from(
    select A_Dt as Dt, A_Na as Na, A_Qty as Qty from a
    union all
    select B_Dt as Dt, B_Na as Na, B_Qty as Qty from b
    union all
    select C_Dt as Dt, C_Na as Na, C_Qty as outward from c
)t
group by t.Dt, t.Na
order by t.Dt;

嗯，在这种情况下，我应该使用左连接或后续查询必须工作。

查询：

#1054 - Unknown column 't.outward' in 'field list'

以下错误：

{{1}}

任何想法都会很棒。谢谢。

Answer 1

首先使用union all将表数据合并为一个，然后按日期和Na列查找数量组的总和。

<强>查询

select t.Dt, t.Na as Inward, sum(t.Qty) as Outward from(
    select A_Dt as Dt, A_Na as Na, A_Qty as Qty from Table_A
    union all
    select B_Dt as Dt, B_Na as Na, B_Qty as Qty from Table_B
)t
group by t.Dt, t.Na
order by t.Dt;

修改

实际上现在不需要组合TableC的数据，但你必须使用连接。

<强>查询

select t1.Dt, t1.Qty as Inward, coalesce(t2.C_Qty, 0) as Outward from( select t.Dt, t.Na, sum(t.Qty) as Qty from( select A_Dt as Dt, A_Na as Na, A_Qty as Qty from Table_A union all select B_Dt as Dt, B_Na as Na, B_Qty as Qty from Table_B )t group by t.Dt, t.Na )t1 left join Table_C t2 on t1.Dt = t2.C_Dt order by 1;

<强>结果

+============+========+=========+ | Dt | Inward | Outward | +------------+--------+---------+ | 2016-08-01 | 200 | 150 | | 2016-08-02 | 100 | 0 | | 2016-08-03 | 100 | 100 | | 2016-08-04 | 200 | 200 | | 2016-08-05 | 150 | 0 | +============+========+=========+

Answer 2

您的查询只需要很小的修正

select t.Dt as Date, sum(t.Qty) as Inward, sum(t.outward) as outward1 from(
   select A_Dt as Dt, A_Na as Na, A_Qty as Qty, 0 as outward from a
   union all
   select B_Dt as Dt, B_Na as Na, B_Qty as Qty, 0 as outward from b
   union all
   select C_Dt as Dt, C_Na as Na, 0 as Qty, C_Qty as outward from c
)t
-- where Na = 'XY'
group by t.Dt, t.Na
order by t.Dt;

MySql：来自两个不同表的两列的总和

2 个答案: