根据子节点获取根节点

CREATE PROCEDURE [dbo].[GetRootID]
(
 @nodeID varchar(36)
)
AS
BEGIN
 SET NOCOUNT ON;
    DECLARE @rootID varchar(36), @currentID varchar(36)

    SELECT @rootID = ParentOrgID, @currentID = @nodeID FROM Organization WHERE OrgID = @nodeID;
    WHILE @rootID !='0'
    BEGIN
     SELECT @rootID = ParentOrgID, @currentID = OrgID FROM Organization WHERE OrgID = @rootID;
    END

    RETURN @currentID;
END
GO

因为我的节点与跟节点是用的唯一标识，是varchar 类型，如果是INT 类型的话，将varchar 改为int  并将@rootID !='0' 改为@rootID>0;即可。

查询语句

DECLARE @return_value varchar(36)
EXEC @return_value = [dbo].[GetRootID]
  @nodeID = '03941ca4-2ee9-4c9c-84f9-df35cd407809'  
select @return_value