数据库 SQL 遍历父子关系表（二叉树）获得所有子节点 所有父节点

数据库  SQL 遍历父子关系表（二叉树）获得所有子节点 所有父节点

创建表
Create Table A
(IDInt,
 fatherIDInt,
 NameVarchar(10)
)
Insert A Select 1,        NULL,       'tt'
Union All Select 2,        1,          'aa'
Union All Select 3,        1,          'bb'
Union All Select 4,        2,          'cc'
Union All Select 5,        2,          'gg'
Union All Select 6,        4,          'yy'
Union All Select 7,        4,          'jj'
Union All Select 8,        7,           'll'
Union All Select 9,        NULL,  'uu'
Union All Select 10,       9,         'oo'
GO
创建函数

//取字子节点
Create Function GetChildren(@ID Int)
Returns @Tree Table (ID Int, fatherID Int, Name Varchar(10))
As
Begin
Insert @Tree Select ID, fatherID, Name From A Where fatherID = @ID
While @@Rowcount > 0
Insert @Tree Select A.ID, A.fatherID, A.Name From A A Inner Join @Tree B On A.fatherID = B.ID And A.ID Not In (Select ID From @Tree)
Return
End
GO

//取父节点

set ANSI_NULLS ON
set QUOTED_IDENTIFIER ON
GO
ALTER Function [dbo].[GetParent](@ID Int)
Returns @Tree Table (ID Int, fatherID Int, NameVar Varchar(10))
As
Begin
Insert @Tree Select ID, fatherID, NameVar From A Where ID = @ID
While @@Rowcount > 0
Insert @Tree Select A.ID, A.fatherID, A.NameVar From A A Inner Join @Tree B On A.ID = B.fatherID And A.ID Not In (Select ID From @Tree)
Return
End

--測試
Select * From dbo.GetChildren(1)

Select * From dbo.GetParent(9)
GO