羊髓,偷拍论坛,黄山热线
<%
dim oconn,ors
set oconn = server.createobject("adodb.connection")
set ors = server.createobject("adodb.recordset")
oconn.open "provider=microsoft.jet.oledb.4.0;data source=" + server.mappath("db1.mdb")
session("conn") = oconn
ors.open "select * from t1",session("conn"),1,1
response.write(ors(0))
ors.close
set ors = nothing
oconn.close
set oconn = nothing
%>
这是网上流传的把connection对象保存在seesion对象中的代码，注意其中的：session("conn") = oconn，对象的复制就是这样子的吗？下边我们来验证一下：
<%
dim oconn,ors
set oconn = server.createobject("adodb.connection")
set ors = server.createobject("adodb.recordset")
oconn.open "provider=microsoft.jet.oledb.4.0;data source=" + server.mappath("db1.mdb")
session("conn") = oconn
ors.open "select * from t1",session("conn"),1,1
response.write(session("conn").connectionstring)
ors.close
set ors = nothing
oconn.close
set oconn = nothing
%>
结果出错，提示"缺少对象: session(...)"！这说明对象并没有复制成功，那session("conn")是什么类型的呢？我们用typename(session("conn"))来测试下，结果为"string"！出于好奇，我们直接输出session("conn")看看：
<%
dim oconn,ors
set oconn = server.createobject("adodb.connection")
set ors = server.createobject("adodb.recordset")
oconn.open "provider=microsoft.jet.oledb.4.0;data source=" + server.mappath("db1.mdb")
session("conn") = oconn
ors.open "select * from t1",session("conn"),1,1
response.write(session("conn"))
ors.close
set ors = nothing
oconn.close
set oconn = nothing
%>
结果为：
provider=microsoft.jet.oledb.4.0;password="";user id=admin;data source=e:wwwdb1.mdb;mode=share deny none;extended properties="";jet oledb:system database="";jet oledb:registry path="";jet oledb:database password="";jet oledb:engine type=5;jet oledb:database locking mode=1;jet oledb:global partial bulk ops=2;jet oledb:global bulk transactions=1;jet oledb:new database password="";jet oledb:create system database=false;jet oledb:encrypt database=false;jet oledb:dont copy locale on compact=false;jet oledb:compact without replica repair=false;jet oledb:sfp=false
这不是connection对象的connectionstring属性值吗？connection对象默认的属性为connectionstring，执行session("conn") = oconn时只是将connection对象默认属性的值赋给session("conn")。那为什么用在ors.open "select * from t1",session("conn"),1,1也能成功呢？查找资料得出recordset对象open方法的第二个参数可以为connection对象，也可以是连接信息的字符串！ok了，那在上边例子中的oconn对象完全是多余的，直接用下边代码即可：
<%
dim ors
set ors = server.createobject("adodb.recordset")
session("conn") = "provider=microsoft.jet.oledb.4.0;data source=" + server.mappath("db1.mdb")
ors.open "select * from t1",session("conn"),1,1
response.write(ors(0))
ors.close
set ors = nothing
%>
结果无错。好了，到现在为止还剩下一个问题没有解决：怎么才是正确的对象复制方法？还是用set语句：
<%
dim oconn,ors
set oconn = server.createobject("adodb.connection")
set ors = server.createobject("adodb.recordset")
oconn.open "provider=microsoft.jet.oledb.4.0;data source=" + server.mappath("db1.mdb")
set session("conn") = oconn
ors.open "select * from t1",session("conn"),1,1
response.write(session("conn").connectionstring)
response.write("<br/>")
response.write(typename(session("conn")))
ors.close
set ors = nothing
oconn.close
set oconn = nothing
%>
这次能显示出connectionstring属性的信息了，结果也显示session("conn")为connection对象！
如对本文有疑问，请在下面进行留言讨论，广大热心网友会与你互动！！
点击进行留言回复
我要评论
网友评论