SQL查询以查找具有相似ID的行，“不” /“确实”在辅助列中具有模式

Question

我正在尝试为共享重复ID（彼此相关）但在辅助列中保留特定模式的行编写查询。

想象一下，这是一个网上商店，每个订单都有多个阶段。 每个orderid在表中都有多个条目。

我想根据具有特定模式的某些Orderid进行排除。

例：

Orderid     Stage     OtherInfo
----------------------------------
1           step 1    random info    
1           step 3    random info
1           step 4    random info
3           step 1    random info
3           step 2    random info
5           step 3    random info
4           step 1    random info
4           step 2    random info
4           step 3    random info

现在，我想查询相应的OrderID符合条件的行-例如：

• 已通过“第1步”和“第3步” //，但未通过“第2步”

预期结果为：

Orderid      Stage     OtherInfo
-----------------------------------
1            step 1    random info
1            step 3    random info
1            step 4    random info

Answer 1

您可以使用聚合并having以下命令获取订单ID：

select orderid
from t
group by orderid
having sum(case when stage = 'step 1' then 1 else 0 end) > 0 and
       sum(case when stage = 'step 3' then 1 else 0 end) > 0 and
       sum(case when stage = 'step 2' then 1 else 0 end) = 0;

要获取原始行：

select t.*
from t
where t.orderid in (select orderid
                    from t
                    group by orderid
                    having sum(case when stage = 'step 1' then 1 else 0 end) > 0 and
                           sum(case when stage = 'step 3' then 1 else 0 end) > 0 and
                           sum(case when stage = 'step 2' then 1 else 0 end) = 0
                   );

Answer 2

使用EXISTS检查条件：

SELECT * 
FROM tablename t
WHERE
  EXISTS (SELECT 1 FROM tablename WHERE tablename.Orderid = t.Orderid AND tablename.stage = 'step 1')
  AND
  EXISTS (SELECT 1 FROM tablename WHERE tablename.Orderid = t.Orderid AND tablename.stage = 'step 3')
  AND
  NOT EXISTS (SELECT 1 FROM tablename WHERE tablename.Orderid = t.Orderid AND tablename.stage = 'step 2');

Answer 3

您也可以使用

SELECT *
FROM T TT
WHERE CASE WHEN EXISTS(SELECT 1 FROM T WHERE OrderID = TT.OrderID AND Stage = 'step 1')
           THEN 
      CASE WHEN EXISTS(SELECT 1 FROM T WHERE OrderID = TT.OrderID AND Stage = 'step 3')
           THEN 
      CASE WHEN NOT EXISTS (SELECT 1 FROM T WHERE OrderID = TT.OrderID AND Stage = 'step 2')
           THEN 1
      END
      END
      END = 1;

要么

SELECT *
FROM T TT
WHERE CASE WHEN EXISTS(SELECT 1 FROM T WHERE OrderID = TT.OrderID AND Stage = 'step 1')
                AND
                EXISTS(SELECT 1 FROM T WHERE OrderID = TT.OrderID AND Stage = 'step 3')
                AND
                NOT EXISTS (SELECT 1 FROM T WHERE OrderID = TT.OrderID AND Stage = 'step 2')
           THEN 1
      END = 1;