Access数据库一种树形结构的实现和子节点查询

BOOL CManageDataBase::GetDepTreeAllSons( int rootItem )

{

CADORecordset Rst(&m_DataBase);

BOOL bResult = FALSE;

CString strSQL;

int curItem = rootItem;

int level = 0;

try

{

strSQL.Format(_T("delete from Temp_DepSons"));

if(!m_DataBase.Execute((LPCTSTR)strSQL))

throw IDS_PROC_ERROR;

strSQL.Format(_T("delete from DepSons"));

if(!m_DataBase.Execute((LPCTSTR)strSQL))

throw IDS_PROC_ERROR;

level = 1;

strSQL.Format(_T("insert into Temp_DepSons values(%d,%d)"), curItem, level);

if(!m_DataBase.Execute((LPCTSTR)strSQL))

throw IDS_PROC_ERROR;

while (level > 0)

{

strSQL.Format(_T("select 1 from Temp_DepSons where levelson = %d"), level);

if (!Rst.Open((LPCTSTR)strSQL))

throw 0;

if (Rst.IsEOF())

{

--level;

continue;

}

strSQL.Format(_T("select top 1 item from Temp_DepSons where levelson = %d"), level);

if (!Rst.Open((LPCTSTR)strSQL))

throw 0;

if (!Rst.IsEOF())

{

Rst.GetFieldValue(0, curItem);

}

strSQL.Format(_T("delete from Temp_DepSons where item = %d"), curItem);

if(!m_DataBase.Execute((LPCTSTR)strSQL))

throw IDS_PROC_ERROR;

strSQL.Format(_T("insert into DepSons(id,parentid) select curno, parentno from Deptree where curno = %d"), curItem);

if(!m_DataBase.Execute((LPCTSTR)strSQL))

throw IDS_PROC_ERROR;

strSQL.Format(_T("insert into Temp_DepSons(item,levelson) select curno, %d from Deptree where parentno = %d"), level+1, curItem);

if(!m_DataBase.Execute((LPCTSTR)strSQL))

throw IDS_PROC_ERROR;

if (m_DataBase.GetRecordsAffected() > 0)

{

++level;

}

}

bResult = TRUE;

}

catch (int nID)

{

m_err.SetLastErrorDescription(nID);

}

return bResult;

}

//树型结构

CREATE TABLE `Deptree` (

`CURNO` INTEGER,

`PARENTNO` INTEGER,

`LAYER` BYTE

)

GO

//结果表

CREATE TABLE `DepSons` (

`id` INTEGER,

`parentid` INTEGER

)

GO

CREATE INDEX id ON DepSons(id)

GO

CREATE INDEX parentid ON DepSons(parentid)

GO

//中间表

CREATE TABLE `Temp_DepSons` (

`item` INTEGER,

`levelson` INTEGER

)

GO

CREATE INDEX id ON Temp_DepSons(item)

GO

CREATE INDEX levels ON Temp_DepSons(levelson)

GO

添加数据后的结构如下：

数据库数据如下：

如果是SQL Server 可以写个函数，这样：

CREATE FUNCTION [dbo].[GetDepTreeAllSons](@RootItem as int)

RETURNS @result TABLE ( id int, parentid int)

AS

BEGIN

declare @level int

declare @curItem int

declare @stack table( item int, level int )

set @curItem = @RootItem --根结点编号

set @level = 1

insert into @stack values( @curItem, @level )

while @level > 0

begin

if not exists( select 1 from @stack where level=@level )

begin

set @level = @level - 1

continue ;

end

select top 1 @curItem = item from @stack where level = @level

delete from @stack where item = @curItem

insert into @result select CURNO,PARENTNO from Deptree where CURNO = @curItem

insert into @stack select CURNO,@level+1 from Deptree where PARENTNO=@curItem

if @@rowcount > 0

set @level = @level + 1

end

--输入出结果

return

END