我在这里发现了类似的问题,但要么我得不到答案,要么他们不适用......这就是我需要的,并认为这很简单: 我有一组项目,每个项目都有一组子项目。每个项目的子项目数量会发生变化。 E.G:
Item 1
SubItem 1-1
SubItem 1-2
SubItem 1-3
Item 2
SubItem 2-1
Item 3
SubItem 3-1
SubItem 3-2
对于一个非常具体的用途,想要的是为每个项目的子项目的每个可能组合添加注释,加上每个子项目的布尔属性,所以它最终如下:
Item 1 Subitem 1-1 = True, Subitem 1-2 = True, Subitem 1-3 = True
Item 1 Subitem 1-1 = True, Subitem 1-2 = True, Subitem 1-3 = False
Item 1 Subitem 1-1 = True, Subitem 1-2 = False, Subitem 1-3 = True
Item 1 Subitem 1-1 = True, Subitem 1-2 = False, Subitem 1-3 = False
Item 1 Subitem 1-1 = False, Subitem 1-2 = True, Subitem 1-3 = True
... (the rest of Item 1 possible combinations)
Item 2 Subitem 2-1 = True
Item 2 Subitem 2-1 = False
Item 3 Subitem 3-1 = True, Subitem 3-2 = True
Item 3 Subitem 3-1 = True, Subitem 3-2 = False
Item 3 Subitem 3-1 = False, Subitem 3-2 = True
Item 3 Subitem 3-1 = False, Subitem 3-2 = False
我尝试了内部连接和交叉连接的各种各样但无法使其工作。我认为布尔部分可以使用交叉连接添加到具有值为True和False的两行的表中,并且我还认为我需要执行“FOR XML”子查询以将子项目放在一行中,但是我没有得到子项目组合
这是我到目前为止所做的:
-- Schema creation and data filling
DECLARE @Item TABLE (ItemId int, Name varchar(50))
DECLARE @Item_SubItem TABLE (ItemId int, SubitemId int)
DECLARE @SubItem TABLE (SubitemId int, Name varchar(50))
INSERT INTO @Item values (1, 'Item 1')
INSERT INTO @Item values (2, 'Item 2')
INSERT INTO @Item values (3, 'Item 3')
INSERT INTO @SubItem values (1, 'SubItem 1-1')
INSERT INTO @SubItem values (2, 'SubItem 1-2')
INSERT INTO @SubItem values (3, 'SubItem 1-3')
INSERT INTO @SubItem values (4, 'SubItem 2-1')
INSERT INTO @SubItem values (5, 'SubItem 3-1')
INSERT INTO @SubItem values (6, 'SubItem 3-2')
INSERT INTO @Item_SubItem values (1, 1)
INSERT INTO @Item_SubItem values (1, 2)
INSERT INTO @Item_SubItem values (1, 3)
INSERT INTO @Item_SubItem values (2, 4)
INSERT INTO @Item_SubItem values (3, 5)
INSERT INTO @Item_SubItem values (3, 6)
select I.Name, SI.Name
from @Item I
inner join @Item_SubItem ISI on ISI.ItemId = I.ItemId
INNER JOIN @SubItem SI on SI.SubitemId = ISI.SubitemId
order by I.Name, SI.Name
-- Actual query
SELECT ItemName = M.name, (SELECT iC.name + '=' + CASE AuxCode WHEN 1 THEN 'True' WHEN 0 THEN 'False' END + ' '
FROM Item_subitem AS iCGM
INNER JOIN Subitem AS iC ON iC.SubitemId = iCGM.SubitemId
CROSS JOIN (SELECT AuxCode = 1 UNION SELECT AuxCode = 0) Aux
WHERE iCGM.ItemId = M.ItemId
ORDER BY iC.name
FOR XML PATH(''))
FROM Item M
所以,这是子查询对我来说失败了。任何帮助将不胜感激!
答案 0 :(得分:3)
以下是如何最多达到4个级别(您的样本数据只需要3个,但我希望确保此功能超出此范围)。你应该能够按照这个模式来达到7,10,你有什么。哦,不要指望这很快。
;WITH z AS
(
SELECT i,inm,si,snm,truth,c FROM
(
SELECT i = i.ItemId, inm = i.Name, si = isi.SubItemId, snm = s.Name,
c = COUNT(isi.SubItemId) OVER (PARTITION BY i.ItemId)
FROM @Item_SubItem AS isi
INNER JOIN @Item AS i ON isi.ItemId = i.ItemId
INNER JOIN @SubItem AS s ON isi.SubItemId = s.SubItemId
) AS y
CROSS JOIN (VALUES('true'),('false')) AS t(truth)
)
SELECT Item = z1.inm,
SubItems = COALESCE( z1.snm + ' = ' + z1.truth,'')
+ COALESCE(', ' + z2.snm + ' = ' + z2.truth,'')
+ COALESCE(', ' + z3.snm + ' = ' + z3.truth,'')
+ COALESCE(', ' + z4.snm + ' = ' + z4.truth,'')
FROM z AS z1
LEFT OUTER JOIN z AS z2
ON z1.i = z2.i AND z1.si < z2.si
LEFT OUTER JOIN z AS z3
ON z2.i = z3.i AND z2.si < z3.si
LEFT OUTER JOIN z AS z4
ON z3.i = z4.i AND z3.si < z4.si
WHERE (z1.c = 1)
OR (z1.c = 2 AND z2.i IS NOT NULL)
OR (z1.c = 3 AND z3.i IS NOT NULL)
OR (z1.c = 4 AND z4.i IS NOT NULL);
给出样本数据的结果:
Item SubItems
------ ---------------------------------------------------------------
Item 1 SubItem 1-1 = true, SubItem 1-2 = true, SubItem 1-3 = true
Item 1 SubItem 1-1 = true, SubItem 1-2 = true, SubItem 1-3 = false
Item 1 SubItem 1-1 = true, SubItem 1-2 = false, SubItem 1-3 = true
Item 1 SubItem 1-1 = true, SubItem 1-2 = false, SubItem 1-3 = false
Item 1 SubItem 1-1 = false, SubItem 1-2 = true, SubItem 1-3 = true
Item 1 SubItem 1-1 = false, SubItem 1-2 = true, SubItem 1-3 = false
Item 1 SubItem 1-1 = false, SubItem 1-2 = false, SubItem 1-3 = true
Item 1 SubItem 1-1 = false, SubItem 1-2 = false, SubItem 1-3 = false
Item 2 SubItem 2-1 = true
Item 2 SubItem 2-1 = false
Item 3 SubItem 3-1 = true, SubItem 3-2 = true
Item 3 SubItem 3-1 = true, SubItem 3-2 = false
Item 3 SubItem 3-1 = false, SubItem 3-2 = true
Item 3 SubItem 3-1 = false, SubItem 3-2 = false
在考虑了这一点之后 编辑,我测试了这个比较首先将一堆信息转储到#temp表,这似乎更好地优化,尽管订单不同(仍按ItemId
排序,但错误值排序更高):
SELECT c.i, c.inm, c.si, c.snm, c.c, t.truth
INTO #x
FROM
(
SELECT
i = i.ItemId, inm = i.Name, si = isi.SubItemId, snm = s.Name,
c = COUNT(isi.SubItemId) OVER (PARTITION BY i.ItemId)
FROM @Item_SubItem AS isi
INNER JOIN @Item AS i ON isi.ItemId = i.ItemId
INNER JOIN @SubItem AS s ON isi.SubItemId = s.SubItemId
) AS c
CROSS JOIN (VALUES('true'),('false')) AS t(truth);
CREATE UNIQUE CLUSTERED INDEX x ON #x(i,si,truth);
SELECT
Item = z1.inm,
SubItems = COALESCE( z1.snm + ' = ' + z1.truth,'')
+ COALESCE(', ' + z2.snm + ' = ' + z2.truth,'')
+ COALESCE(', ' + z3.snm + ' = ' + z3.truth,'')
+ COALESCE(', ' + z4.snm + ' = ' + z4.truth,'')
FROM #x AS z1
LEFT OUTER JOIN #x AS z2 ON z1.i = z2.i AND z1.si < z2.si
LEFT OUTER JOIN #x AS z3 ON z2.i = z3.i AND z2.si < z3.si
LEFT OUTER JOIN #x AS z4 ON z3.i = z4.i AND z3.si < z4.si
WHERE (z1.c = 1)
OR (z1.c = 2 AND z2.i IS NOT NULL)
OR (z1.c = 3 AND z3.i IS NOT NULL)
OR (z1.c = 4 AND z4.i IS NOT NULL);
DROP TABLE #x;
如果基础表被索引,原始版本会更有利,例如
DECLARE @Item TABLE (ItemId int PRIMARY KEY, Name varchar(50));
DECLARE @Item_SubItem TABLE (ItemId int, SubitemId int,
PRIMARY KEY (ItemId,SubItemId));
DECLARE @SubItem TABLE (SubitemId int PRIMARY KEY, Name varchar(50));
您应该根据实际数据/架构测试这两种变体。