Question

这是我的表：
帐户

ac             name
120            Tom
130            Jony
140            Jone

bread_sale

ac             pcs        amount       date
120            12           60         2018-01-03
120            10           50         2018-01-04
140            8            40         2018-01-04
130            5            25         2018-01-05

water_sale

ac             pcs        amount       date
130            2            30         2018-01-03
130            5            75         2018-01-04
140            3            45         2018-01-04
130            4            60         2018-01-05
120            5            75         2018-01-07

以下是我尝试的查询：

select account.ac, 
       account.name, 
       bread_sale.amount as BSAmount,  
       bread_sale.date as BSDate, 
       water_sale.amount as WSAmount, 
       water_sale.date as WSDate
from account left outer join bread_sale on account.ac = bread_sale.ac 
             left outer join water_sale on water_sale.ac = account.ac 
order by account.ac

结果如下：

ac             name       BSAmount   BSdate       WSAmount   WSdate
120            Tom        30         2018-01-03   75         2018-01-07
120            Tom        75         2018-01-04   75         2018-01-07
130            Jony       45         2018-01-05   30         2018-01-03
130            Jony       60         2018-01-05   75         2018-01-04
130            Jony       75         2018-01-05   60         2018-01-05
140            Jone       75         2018-01-04   45         2018-01-04

但我想获得这样的东西：

ac             name       BSAmount   BSdate       WSAmount   WSdate
120            Tom        60         2018-01-03   75         2018-01-07
120            Tom        50         2018-01-04   0          2018-01-07
130            Jony       25         2018-01-05   30         2018-01-03
130            Jony       0          2018-01-05   75         2018-01-04
130            Jony       0          2018-01-05   60         2018-01-05
140            Jone       40         2018-01-04   45         2018-01-04

在2018-01-07，汤姆没有出售水，但我得到75金额。有人帮帮我，

Answer 1

select account.ac, 
   account.name, 
   bread_sale.amount as BSAmount,  
   bread_sale.date as BSDate, 
   water_sale.amount as WSAmount, 
   water_sale.date as WSDate
from account left outer join bread_sale on account.ac = bread_sale.ac 
             left outer join water_sale on water_sale.ac = bread_sale.ac 
order by account.ac

此查询将生成此结果。您的零将被正确的值替换。我希望你可能需要这个重新开始。

ac             name       BSAmount   BSdate       WSAmount   WSdate
120            Tom        60         2018-01-03   75         2018-01-07
120            Tom        50         2018-01-04   75         2018-01-07
130            Jony       25         2018-01-05   30         2018-01-03
130            Jony       25         2018-01-05   75         2018-01-04
130            Jony       25         2018-01-05   60         2018-01-05
140            Jone       40         2018-01-04   45         2018-01-04

Answer 2

这是可以实现的但是很麻烦，可能效率不高。面包水与交易账户之间存在关系。可以建立跨越面包和水的最大行数，然后重新加入行号。换句话说，面包和水在位置基础上连接（即订单行显示在表格中）结果查询非常糟糕，并且比我个人感觉更频繁地解析数据。

所以

select * from
(
select c.ac cac,t.name tname,d.amount bsamount,  d.dt ddt,
         e.amount wsamount ,e.dt edt
         ,
         case when d.dt is not null and d.dt < e.dt then d.dt
               when d.dt is not null and e.dt is null then d.dt
         else e.dt
         end as sortorder
 from
(
select *
from
(
select bs.ac,
         if(bs.ac <> @p,@rn:=1,@rn:=@rn+1) rn,
         @p:=bs.ac p
from bs
cross join (select @rn:=0,@p:=0) r
order by bs.ac,bs.dt
) a  
union 
(
select ac2,rn1,p1
from
(
select ws.ac ac2,
         if(ws.ac <> @p1,@rn1:=1,@rn1:=@rn1+1) rn1,
         @p1:=ws.ac p1
from ws
cross join (select @rn1:=0,@p1:=0) r
order by ws.ac,ws.dt
) b
) 
) c
left join 
(
select bs.ac,pcs,amount,dt,
         if(bs.ac <> @p3,@rn3:=1,@rn3:=@rn3+1) rn3,
         @p3:=bs.ac p
from bs
cross join (select @rn3:=0,@p3:=0) r
order by bs.ac,bs.dt
) d
on d.ac = c.ac and  d.rn3 = c.rn
left join
(
select ws.ac,pcs,amount,dt,
         if(ws.ac <> @p4,@rn4:=1,@rn4:=@rn4+1) rn4,
         @p4:=ws.ac p
from ws
cross join (select @rn4:=0,@p4:=0) r
order by ws.ac,ws.dt
) e
on e.ac = c.ac and  e.rn4 = c.rn
join t on t.ac = c.ac
) f
order by cac , sortorder;

+------+-------+----------+------------+----------+------------+------------+
| cac  | tname | bsamount | ddt        | wsamount | edt        | sortorder  |
+------+-------+----------+------------+----------+------------+------------+
|  120 | Tom   |       60 | 2018-01-03 |       75 | 2018-01-07 | 2018-01-03 |
|  120 | Tom   |       50 | 2018-01-04 |     NULL | NULL       | 2018-01-04 |
|  130 | Jony  |       25 | 2018-01-05 |       30 | 2018-01-03 | 2018-01-03 |
|  130 | Jony  |     NULL | NULL       |       75 | 2018-01-04 | 2018-01-04 |
|  130 | Jony  |     NULL | NULL       |       60 | 2018-01-05 | 2018-01-05 |
|  140 | Jone  |       40 | 2018-01-04 |       45 | 2018-01-04 | 2018-01-04 |
+------+-------+----------+------------+----------+------------+------------+
6 rows in set (0.00 sec)

3 mysql表连接但没有得到我想要的预期结果

2 个答案: