zoukankan      html  css  js  c++  java
  • sql server 2000/2005递归

    /*

    递归查询 塗聚文
    ---SQL Server 2005环境下的实现:

    */
    --生成测试数据
    create table Dept(ID int,ParentID int,msg varchar(20))
    insert into Dept select 1,0,'d'
    insert into Dept select 2,1,'s'
    insert into Dept select 3,1,'nl'
    insert into Dept select 4,2,'d'
    insert into Dept select 5,3,'s'
    insert into Dept select 6,5,'f'
    insert into Dept select 7,6,'d'
    go

    select * from Dept
    Declare @Id Int
    Set @Id = 1; ---在此修改父节点

    With RootNodeCTE(Id,ParentID,msg)
    As
    (
    Select ID,ParentID,msg From Dept
    Where ParentID In (@Id)
    Union All
    Select Dept.ID,Dept.ParentID,Dept.msg From RootNodeCTE
    Inner Join Dept
    On RootNodeCTE.Id = Dept.ParentID
    )
    Select * From RootNodeCTE

    ---SQL Server 2000环境下的实现:
    --生成测试数据 塗聚文 Geovin Du
    create table Dept(ID int,ParentID int,msg varchar(20))
    insert into Dept select 1,0,'d'
    insert into Dept select 2,1,'s'
    insert into Dept select 3,1,'nl'
    insert into Dept select 4,2,'d'
    insert into Dept select 5,3,'s'
    insert into Dept select 6,5,'f'
    insert into Dept select 7,6,'d'
    go

    select * from Dept


    --创建用户定义函数
    Create function [dbo].[GetChild](@ID varchar(10))
    returns @t table(ID varchar(10),ParentID varchar(10),msg varchar(20),Level int)
    as
    begin
    declare @i int
    set @i = 1
    insert into @t select @ID,@ID,null,0 --当前级,本级,如果不要的话可以注释掉或再加个参数来选择操作
    insert into @t select ID,ParentID,msg,@i from Dept where ParentID = @ID

    while @@rowcount<>0
    begin
    set @i = @i + 1
    insert into @t
    select
    a.ID,a.ParentID,a.msg,@i
    from
    Dept a,@t b
    where
    a.ParentID=b.ID and b.Level = @i-1
    end
    return
    end


    --执行查询
    select ID from dbo.GetChild(2)
    go

    --删除测试数据
    drop function GetChild
    drop table Dept

  • 相关阅读:
    排序算法之冒泡排序
    hadoop程序启动
    开播小记
    3.3面向对象封装案例1摆家具
    3.2面向对象基础语法
    3.1类和对象
    2.12函数进阶
    2.11变量的引用_可变不可变类型_局部变量和全局变量
    2.10第二章综合应用_名片管理系统
    2.8函数基础
  • 原文地址:https://www.cnblogs.com/zcm123/p/4323182.html
Copyright © 2011-2022 走看看