Question

我有一个关于三个表的连接的查询。第3个表中的一列具有布尔值。。表2和表3与product_id连接，表3上的每个product_id可以作为接收值与真值和假值相关联。我需要一个查询来返回表1中的所有记录，这些记录与表3中的接收值仅具有真值的产品相关联。在下面的示例数据中，我只想返回GHI

Table 1 - Sale
ID  sale#
1   ABC
2   DEF
3   GHI

Table 2 PO      Table 1 join Table 2 on Table1.ID = Table 2.SaleID
ID SaleID
1   1
2   1
3   2
4   3
5   3

Table 3
ID POID  Received Table 2 right join table 3 on Table 2.ID = Table 3.POID 
1   1     True
2   1     False
3   2     True
4   3     False
5   4     True
6   5     True
7   5     True

在下午试验之后，我使用NOT IN使其工作，但是我的数据集（当前只有大约2000条记录）非常慢我认为这可能是因为它必须重新创建连接。似乎应该有一种更优雅的方式来实现这一目标。

SELECT Distinct Table1.id, Table3.received
FROM Table3 INNER JOIN (Table2 INNER JOIN Table1 ON Table2.saleID = Table1.id) 
  ON Table3.POID = Table2.id
WHERE ((Table3.received)=True) and Table1.id NOT IN (
  SELECT Table1.id
  FROM Table3 INNER JOIN (Table2 INNER JOIN Table1 ON Table2.saleID = Table1.id) 
    ON Table3.POID = Table2.id
  WHERE ((Table3.received)=False));

Answer 1

我相信这是您需要的查询

select 
  Table1.* 
from 
  Table1 join Table2 on Table1.id = Table2.saleid
  join table3 on table3.POID = Table2.ID
where
  table3.received = true

Answer 2

首先，只需从表3中选择具有表3中的真值输入的产品，这可以通过POID上的自联接来完成。然后结果可以与table2和table1

结合使用

select 
   Table1.* 
from 
Table1 join Table2 
   on Table1.id = Table2.saleid
join 
   (select t3.poid 
    from 
    Table3 t3 join Table3 t4
       on t.POID = Table4.POID) 
     where t3.received = true and t4.received  = true) all_true
on all_true.POID = Table2.ID

Answer 3

您需要做的就是确保特定count的{{1}}条记录等于值sale# = {的记录的count {1}}又称count-if（在SQL中没有显式存在）。在SQL中完成count-if的方法是执行received。

示例数据设置：

True

<强>答案：

...sum(case ... when ... then 1 else 0 end)...

<强>输出：

create table dbo.Sale
    (
        ID int
        , sale# char(3)
    )

create table dbo.PO
    (
        ID int
        , SaleID int
    )

create table dbo.Received
    (
        ID int
        , POID int
        , Received char(5)
    )

insert into dbo.Sale
values (1, 'ABC'), (2, 'DEF'), (3, 'GHI')

insert into dbo.PO
values (1,1), (2,1), (3,2), (4,3), (5,3)

insert into dbo.Received
values (1, 1, 'True')
    , (2, 1, 'False')
    , (3, 2, 'True')
    , (4, 3, 'False')
    , (5, 4, 'True')
    , (6, 5, 'True')
    , (7, 5, 'True')

Answer 4

谢谢tarheel 你把我放在了赛道上。我做了一个真/假，并添加了Sum（已接收）=计数（已接收）

SELECT DISTINCT Table1.id
FROM Table3 INNER JOIN (Table2 INNER JOIN Table1 ON Table2.saleID = Table1.id) ON Table3.POID = Table2.id
GROUP BY Table1.id
HAVING (-1*(Sum(Table3.received))=Count([Table3].[received]));

SQL连接仅返回所有行匹配的记录

4 个答案: