树形数据查询示例

--树形数据查询示例
--作者: 邹建

if exists (select * from dbo.sysobjects where id = object_id(N'[tb]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
drop table [tb]
GO

--示例数据
create table [tb]([id] int identity(1,1),[pid] int,name varchar(20))
insert [tb] select 0,'中国'
union all select 0,'美国'
union all select 0,'加拿大'
union all select 1,'北京'
union all select 1,'上海'
union all select 1,'江苏'
union all select 6,'苏州'
union all select 7,'常熟'
union all select 6,'南京'
union all select 6,'无锡'
union all select 2,'纽约'
union all select 2,'旧金山'
go

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[f_cid]') and xtype in (N'FN', N'IF', N'TF'))
drop function [dbo].[f_cid]
GO

/*--树形数据处理

查询指定id的所有子

--邹建 2003-12(引用请保留此信息)--*/

/*--调用示例

--调用(查询所有的子)
select a.*,层次=b.[level] from [tb] a,f_cid(2)b where a.[id]=b.[id]
--*/
create function f_cid(
@id int
)returns @re table([id] int,[level] int)
as
begin
declare @l int
set @l=0
insert @re select @id,@l
while @@rowcount>0
begin
set @l=@l+1
insert @re select a.[id],@l
from [tb] a,@re b
where a.[pid]=b.[id] and b.[level]=@l-1
end
/*--如果只显示最明细的子(下面没有子),则加上这个删除
delete a from @re a
where exists(
select 1 from [tb] where [pid]=a.[id])
--*/
return
end
go

--调用(查询所有的子)
select a.*,层次=b.[level] from [tb] a,f_cid(2)b where a.[id]=b.[id]
go

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[f_pid]') and xtype in (N'FN', N'IF', N'TF'))
drop function [dbo].[f_pid]
GO

/*--树形数据处理

查询指定id的所有父

--邹建 2003-12(引用请保留此信息)--*/

/*--调用示例

--调用(查询所有的父)
select a.* from [tb] a,f_pid(7)b where a.[id]=b.[id]
--*/
create function f_pid(
@id int
)returns @re table([id] int,[level] int)
as
begin
declare @l int
set @l=0
insert @re select [pid],@l from [tb] where [id]=@id and [pid]<>0
while @@rowcount>0
begin
set @l=@l+1
insert @re select a.[pid],@l
from [tb] a,@re b
where a.[id]=b.[id] and b.[level]=@l-1 and a.[pid]<>0
end
return
end
go

--调用(查询所有的父)
select a.* from [tb] a,f_pid(7)b where a.[id]=b.[id]
go

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[f_id]') and xtype in (N'FN', N'IF', N'TF'))
drop function [dbo].[f_id]
GO

/*--树形数据处理

级别及排序字段

--邹建 2003-12(引用请保留此信息)--*/

/*--调用示例

--调用函数实现分级显示
select replicate('-',b.[level]*4)+a.name
from [tb] a,f_id()b
where a.[id]=b.[id]
order by b.sid
--*/
create function f_id()
returns @re table([id] int,[level] int,sid varchar(8000))
as
begin
declare @l int
set @l=0
insert @re select [id],@l,right(10000+[id],4)
from [tb] where [pid]=0
while @@rowcount>0
begin
set @l=@l+1
insert @re select a.[id],@l,b.sid+right(10000+a.[id],4)
from [tb] a,@re b
where a.[pid]=b.[id] and b.[level]=@l-1
end
return
end
go

--调用函数实现分级显示
select replicate('-',b.[level]*4)+a.name
from [tb] a,f_id()b
where a.[id]=b.[id]
order by b.sid
go

if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[p_copyid]') and OBJECTPROPERTY(id, N'IsProcedure') = 1)
drop procedure [dbo].[p_copyid]
GO

/*--树形数据处理

将一个结点下的所有子复制到另一个结点下
目标结点下不能有子结点

--邹建 2005-01(引用请保留此信息)--*/

/*--调用示例

--调用存储过程实现复制
exec p_copyid 2,10
select * from [tb]
--*/
create proc p_copyid
@s_id int,--要复制的源结点
@d_id int--目标结点
as
if not exists(select * from [tb] where [id]=@d_id)
begin
raiserror(N'目标结点 "%d" 不存在!',1,16,@d_id)
return
end

declare @s nvarchar(4000)
select @s=N'create table #t([nid] int identity('
+rtrim(max([id])+1)--复制后的结点为表中最大的结点+1
+',1),[id] int,[pid] int,level int,[name] nvarchar(50))
declare @l int
set @l=0
insert #t([id],[pid],level,[name]) select [id],@d_id,@l,[name]
from [tb] where [pid]=@s_id
while @@rowcount>0
begin
set @l=@l+1
insert #t([id],[pid],level,[name])
select a.[id],b.nid,@l,a.[name]
from [tb] a,#t b
where a.[pid]=b.[id]
and b.level=@l-1
end
set identity_insert [tb] on
insert [tb]([id],[pid],[name])
select nid,[pid],[name] from #t
set identity_insert [tb] off'
from [tb]
exec sp_executesql @s
,N'@s_id int,@d_id int'
,@s_id,@d_id
go