展平包含引用SQL Server 2005中其他行的行的表格

Question

我面臨的問題是，在處理未完全標準化的表格時偶爾會出現問題。這是問題。想象一下有4列的表格，我們稱這個表爲dbo.Hierarchical。下面是表的定義：

if OBJECT_ID('dbo.Hierarchical') is not null 
drop table dbo.Hierarchical 

create table dbo.Hierarchical 
(
    colID int not null identity(1,1) primary key 
,GroupName varchar(5) not null 
,IsAtomic bit not null 
,Constituent varchar(5) null 
) 

此表可以具有組名是原子的，這意味着它不沒有部件，或者不能夠原子。在這種情況下，GroupName可以包含其他GroupNames。

爲了清楚起見，讓我們填寫一些數據。

set nocount on 
insert into dbo.Hierarchical values ('A',0,'B') 
insert into dbo.Hierarchical values ('A',0,'C') 
insert into dbo.Hierarchical values ('B',1,'B') 
insert into dbo.Hierarchical values ('C',0,'K') 
insert into dbo.Hierarchical values ('C',0,'L') 
insert into dbo.Hierarchical values ('D',0,'E') 
insert into dbo.Hierarchical values ('D',0,'F') 
insert into dbo.Hierarchical values ('D',0,'G') 
insert into dbo.Hierarchical values ('E',1,'E') 
insert into dbo.Hierarchical values ('F',1,'F') 
insert into dbo.Hierarchical values ('G',0,'H') 
insert into dbo.Hierarchical values ('G',0,'I') 
insert into dbo.Hierarchical values ('H',1,'H') 
insert into dbo.Hierarchical values ('I',1,'I') 
insert into dbo.Hierarchical values ('J',1,'J') 
insert into dbo.Hierarchical values ('K',1,'K') 
insert into dbo.Hierarchical values ('L',1,'L') 
insert into dbo.Hierarchical values ('M',1,'M') 
insert into dbo.Hierarchical values ('N',1,'N') 
set nocount off 

現在，如果我們來看一個簡單的SELECT * FROM dbo.Hierarchical我們得到如下：

GroupName colID  IsAtomic Constituent 
A   1   0   B 
A   2   0   C 
B   3   1   B 
C   4   0   K 
C   5   0   L 
D   6   0   E 
D   7   0   F 
D   8   0   G 
E   9   1   E 
F   10   1   F 
G   11   0   H 
G   12   0   I 
H   13   1   H 
I   14   1   I 
J   15   1   J 
K   16   1   K 
L   17   1   L 
M   18   1   M 
N   19   1   N 

吆，這是長篇大論。現在請注意，前兩行有GroupName A和Constiuents B和C.B是Atomic，所以它沒有更多的便利。但是，C具有便祕K，L（K和L是原子）。我怎樣才能創建一個視圖，將這張表壓平，這樣我只能看到GroupName和Atomic constiuents。在組名A的情況下，我看到768,16 3行

A B 
A K 
A L 

Answer 1

試試這個：

--just a repeat of OP's original table and data 
DECLARE @Hierarchical table 
(colID int not null identity(1,1) primary key 
,GroupName varchar(5) not null 
,IsAtomic bit not null 
,Constituent varchar(5) null) 
set nocount on 
insert into @Hierarchical values ('A',0,'B');insert into @Hierarchical values ('A',0,'C'); 
insert into @Hierarchical values ('B',1,'B');insert into @Hierarchical values ('C',0,'K'); 
insert into @Hierarchical values ('C',0,'L');insert into @Hierarchical values ('D',0,'E'); 
insert into @Hierarchical values ('D',0,'F');insert into @Hierarchical values ('D',0,'G'); 
insert into @Hierarchical values ('E',1,'E');insert into @Hierarchical values ('F',1,'F'); 
insert into @Hierarchical values ('G',0,'H');insert into @Hierarchical values ('G',0,'I'); 
insert into @Hierarchical values ('H',1,'H');insert into @Hierarchical values ('I',1,'I'); 
insert into @Hierarchical values ('J',1,'J');insert into @Hierarchical values ('K',1,'K'); 
insert into @Hierarchical values ('L',1,'L');insert into @Hierarchical values ('M',1,'M'); 
insert into @Hierarchical values ('N',1,'N');set nocount off 

--declare and set starting position 
DECLARE @Start varchar(5) 
SET @Start='A' 

--get the data 
;WITH HierarchicalTree AS 
(
    SELECT 
     GroupName, Constituent, 1 AS LevelOf 
     FROM @Hierarchical 
     WHERE GroupName=@Start 
    UNION ALL 
     SELECT 
      t.GroupName, h.Constituent, t.LevelOf+1 
     FROM HierarchicalTree   t 
      INNER JOIN @Hierarchical h ON t.Constituent=h.GroupName 
     WHERE h.Constituent!=h.GroupName AND h.IsAtomic=0 
) 
SELECT 
    t.GroupName,t.Constituent 
    FROM HierarchicalTree  t 
     INNER JOIN @Hierarchical h ON t.Constituent=h.GroupName 
    WHERE h.IsAtomic=1 

OUTPUT：

GroupName Constituent 
--------- ----------- 
A   B 
A   K 
A   L 

(3 row(s) affected) 

Answer 2

嗯，這的確你問什麼，但如果它嵌套一旦它只會工作。如果你需要遞歸，那麼你將不得不使用CTE。

select a.GroupName, 
     b.Constituent 

From dbo.Hierarchical a 

Left Join dbo.Hierarchical b on a.Constituent = b.GroupName 

這是你所需要的還是我完全錯過了這一點？

Answer 3

爲了完整起見，我隨信附上了設置了問題，並給出瞭解決方案整個SQL腳本文件。再次，Hattip KM。

use tempdb 
go 

if OBJECT_ID('dbo.Hierarchical') is not null 
    drop table dbo.Hierarchical 

create table dbo.Hierarchical 
(
    colID   int   not null identity(1,1) primary key 
    ,GroupName  varchar(5) not null 
    ,IsAtomic  bit   not null 
    ,Constituent varchar(5) null 
) 

set nocount on 
insert into dbo.Hierarchical values ('A',0,'B') 
insert into dbo.Hierarchical values ('A',0,'C') 
insert into dbo.Hierarchical values ('B',1,'B') 
insert into dbo.Hierarchical values ('C',0,'K') 
insert into dbo.Hierarchical values ('C',0,'L') 
insert into dbo.Hierarchical values ('D',0,'E') 
insert into dbo.Hierarchical values ('D',0,'F') 
insert into dbo.Hierarchical values ('D',0,'G') 
insert into dbo.Hierarchical values ('E',1,'E') 
insert into dbo.Hierarchical values ('F',1,'F') 
insert into dbo.Hierarchical values ('G',0,'H') 
insert into dbo.Hierarchical values ('G',0,'I') 
insert into dbo.Hierarchical values ('H',1,'H') 
insert into dbo.Hierarchical values ('I',1,'I') 
insert into dbo.Hierarchical values ('J',1,'J') 
insert into dbo.Hierarchical values ('K',1,'K') 
insert into dbo.Hierarchical values ('L',1,'L') 
insert into dbo.Hierarchical values ('M',1,'M') 
insert into dbo.Hierarchical values ('N',1,'N') 
set nocount off 

-- see what the over nomalized table looks like 
-- before you call the CTE. Notice how A has 
-- Constiuents B, and C. And further down 
-- C is made up of K, and L. 

-- select * from dbo.Hierarchical 

go 


-- Use the CTE to 
;WITH HierarchicalTree AS 
( 
    SELECT 
     GroupName, Constituent, 1 AS LevelOf 
     FROM dbo.Hierarchical 
     --WHERE GroupName=@Start 
    UNION ALL 
     SELECT 
      t.GroupName, h.Constituent, t.LevelOf+1 
     FROM HierarchicalTree   t 
      INNER JOIN dbo.Hierarchical h ON t.Constituent=h.GroupName 
     WHERE h.Constituent!=h.GroupName AND h.IsAtomic=0 
) 


-- Now, notice this query will give us A with the it's 
-- Constiuent elements B, K, and L 
SELECT 
    t.GroupName,t.Constituent, h.IsAtomic, t.LevelOf 
    FROM HierarchicalTree  t 
     INNER JOIN dbo.Hierarchical h ON t.Constituent=h.GroupName 
    --WHERE h.IsAtomic=1 
    Where h.Constituent = h.GroupName 
order by 
    t.GroupName 

if OBJECT_ID('tempdb..Hierarchical') is not null 
    drop table dbo.Hierarchical