一条语句中所有名称的查询表

Question

我有一个不能更改的表，并且试图用一种适当的方法来处理我的头，以一种基于给定值的语句在一个语句中查询该表。

该表大致如下所示：

我需要的是一种仅使用SubBody代码查询表的方法，以便获取与其关联的所有名称。

例如，

<query> where SubBody = '1001'

回报

| HName | HSName | BName | BSName   |
+-----------------------------------+
| Toys  | Sport  | Ball  | Baseball |

Answer 1

SELECT Head.Name as HName , 
       SubHead.Name as HSName , 
       Body.Name as BName , 
       SubBody.Name as BSName   
FROM yourTable as SubBody
JOIN yourTable as Body
  ON SubBody.Body = Body.Body
 AND Body.SubBody IS NULL
JOIN yourTable as SubHead
  ON Body.SubHead = SubHead.SubHead
 AND SubHead.Body IS NULL
JOIN yourTable as Head
  ON SubHead.Head = Head.Head
 AND Head.SubHead IS NULL
WHERE  SubBody.SubBody = '1001'

Answer 2

尽管您可以将逻辑表示为联接，但是出于某些原因，首先要想到相关子查询：

select (select th.name from t th where th.head = t.head and th.subhead is null) as hname,
       (select ts.name from t ts where ts.head = t.head and ts.subhead = t.subhead and t.body is null) as sname,
       (select tb.name from t tb where tb.head = t.head and tb.subhead = t.subhead and tb.body = t.body and tb.subbody is null) as bname,      
       t.name as bsname
from t 
where t.subbody = 1001

Answer 3

这个答案接近胡安·卡洛斯（Juan Carlos）发表的内容。 您喜欢哪一种取决于您的风格。

WITH BaseRecord AS(
    SELECT *
    FROM ToyTable
    WHERE SubBody = '1001'
)
SELECT 
    h.Name AS HName,
    hs.Name AS HSName,
    b.Name AS BName,
    bs.Name AS BSName
FROM BaseRecord bs
    INNER JOIN ToyTable b ON bs.Body = b.Body AND ISNULL(b.SubBody,'') = ''
    INNER JOIN ToyTable hs ON bs.SubHead = hs.SubHead AND ISNULL(hs.Body,'') = ''
    INNER JOIN ToyTable h ON bs.Head = h.Head AND ISNULL(h.SubHead,'') = ''

我不确定您的“空”单元格是否包含空值或空字符串。 无论哪种方式，都将两者都考虑在内。