触发器、数据库连接的问题

[bee6803]

1、有两个表A、B表结构相同。问：如何用触发器实现当向表A插入记录时自动向表B插入记录？
2、使用连接时，是一直保持数据库连接好呢？还是要使用数据库时重新连数据库好呢？哪一种连接方式占用资源少些？哪种方式可以使软件运行得更快一些？

[bee6803]

谢谢lxzm1001(*蓝星之梦*) 。不知第二个问题要如何解释呢？

[bee6803]

'这是用VB写的一个连接与关闭连接的语句
Public Sub OpenOrCloseDataBaseConnection()
If Con.State = 1 Then
Con.Close
Else
Con.CursorLocation = adUseClient
Con.Open strConnectionString
End If
End Sub

我在要连数据库时调用OpenOrCloseDatabaseConnection打开连接
使用完毕时调用OpenOrCloseDatabaseConnection关闭连接。
不知这样能否达到如题的目的????

[bee6803]

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

CREATE TABLE [dbo].[T_STONEKC] (
[id] [char] (10) COLLATE Chinese_PRC_CI_AS NOT NULL primary key,
[ck] [char] (10) COLLATE Chinese_PRC_CI_AS NOT NULL primary key,
[kcsl] [int] NULL default 0,
[jg] [float] NULL default 0
) ON [PRIMARY]
GO

我的本意是想用id\ck两个作为主键，但不知在语句中要如何写啊。这样写会出错。

[lxzm1001]

create trigger triggername on tablename1
for
delete
as
delete tablename2 from deleted where deleted.id=tablename2.id

[lxzm1001]

看错。。是插入

[lxzm1001]

create table a(id int,col varchar(10))
insert a select 1,'111'
union all select 2,'222'
union all select 3,'333'
create table b(id int,col varchar(10))
insert b select 1,'1111'
union all select 2,'2222'
union all select 3,'3333'
go
create trigger test on a
for insert
as
insert b select * from inserted
go
select * from a
select * from b
go
insert a select 4,'444'
go
select * from a
select * from b

[itblog]

create trigger trigger_AtoB on A
for insert
as
begin
insert B select * from inserted
end


使用数据库时重新连数据库好,资源占用小~