需要在 sql server 中返回一个有 start 和 END 的 ID

Question

我有一个场景，我需要找到其中只有 start 和 END 的 ID。下表供参考。

Declare @T Table ( ID int, Name varchar(100))

Insert into @T values (1,'Start')
Insert into @T values (1,'END')
Insert into @T values (1,'Stuart')
Insert into @T values (1,'robin')
Insert into @T values (2,'Start')
Insert into @T values (2,'END')
Insert into @T values (3,'Start')
Insert into @T values (4,'END')

我希望输出为：

ID 名称
2 开始
2 结束

我想要那些只有开始和结束的ID。

到目前为止我尝试了什么：

SELECT * FROM @T t 
WHERE EXISTS (SELECT * FROM @T WHERE id = t.id AND name = 'start')
AND EXISTS (SELECT * FROM @T WHERE id = t.id AND name = 'END')

但我的查询也给出了 ID 1。

谁能帮我解决这个问题。

Answer 1

您也可以使用 group by 函数来做到这一点，如下所示

WITH cte AS 
(
SELECT 1 AS id , 'Start' AS name 
UNION ALL 
SELECT 1  AS id ,'END'  AS name 
UNION ALL
SELECT 1 AS id ,'Stuart'  AS name
UNION ALL
SELECT 1 AS id ,'robin'  AS name  
UNION ALL
SELECT 2  AS id ,'Start'  AS name 
UNION ALL
SELECT 2 AS id ,'END'  AS name
UNION ALL
SELECT 3 AS id ,'Start'  AS name  
UNION ALL
SELECT 4 AS id ,'END'  AS name 
)
SELECT T.ID,SUM(T.VAL)AS SUM
FROM 
(
SELECT  id,name , CASE WHEN name='Start' THEN 1
                       WHEN name='END' THEN  2
                       ELSE 3
                  END AS VAL 
                    
FROM cte 
)T 
GROUP BY T.ID 
HAVING SUM(T.VAL) =3

Answer 2

您可以通过 CTE 获得分组计数和总计数为 2。

Declare @T Table ( ID int, Name varchar(100))

Insert into @T values (1,'Start')
Insert into @T values (1,'END')
Insert into @T values (1,'Stuart')
Insert into @T values (1,'robin')
Insert into @T values (2,'Start')
Insert into @T values (2,'END')
Insert into @T values (3,'Start')
Insert into @T values (4,'END')

;WITH CTE_Total_StartEnd AS
(
select id, count(*) AS Total_Cnt
, COUNT( case when Name IN ('Start') THEN 1 END) as start_cnt 
, COUNT( case when Name IN ('End') THEN 1 END) as end_cnt 
from @t
group by id
having  COUNT( case when Name IN ('Start') THEN 1 END) =1 and
COUNT( case when Name IN ('End') THEN 1 END) = 1  and
count(*) = 2
)
SELECT t.* from @t t
inner join CTE_Total_StartEnd as c 
ON c.id = t.id

+----+-------+
| ID | Name  |
+----+-------+
|  2 | Start |
|  2 | END   |
+----+-------+

Answer 3

我想你的问题是记录 1 也有一个“斯图尔特”？

因此，您可以在 WHERE 中进行类似的检查，例如，

SELECT * FROM @T t 
WHERE EXISTS (SELECT * FROM @T WHERE id = t.id AND name = 'start')
AND EXISTS (SELECT * FROM @T WHERE id = t.id AND name = 'END')
AND NOT EXISTS (SELECT * FROM @T WHERE id = t.id AND name NOT IN ('start','END'))

请注意，您可能需要考虑

• 如果您有两个“开始”行或两个“结束”行（例如，开始-开始-结束），会发生什么情况？你甚至可以有两个“开始”行（例如，开始-开始）吗？
• 如果您有一个空白/NULL（例如，start-NULL-end）会发生什么？

---

编辑：删除了“如果它们出现故障（例如，结束开始）会发生什么？”作为一个问题，因为数据中根本没有排序（例如，甚至没有隐式排序）。

Answer 4

你能试试这个吗？请注意我在 sql 末尾添加了整理命令。 SQL Server check case-sensitivity?

SELECT * FROM @T t 
WHERE EXISTS (SELECT * FROM @T WHERE id = t.id AND name = 'start' COLLATE SQL_Latin1_General_CP1_CS_AS)
AND EXISTS (SELECT * FROM @T WHERE id = t.id AND name = 'END' COLLATE SQL_Latin1_General_CP1_CS_AS)