使用组件封装数据库操作(二)

来源：作者：出处：巧巧读书 2006-09-12 进入讨论组

　　前段日子发表的文章，数据库的连接代码可以直接在ASP文件中显示出来。这次又进行了一次封装。
　　打开vb，新建Activex控件，工程名称为WebDb，类模块名称为GetInfomation
　　引用”Microsoft Activex Data Object 2.6 Library ”

Private Conn As ADODB.Connection
Private Rs As ADODB.Recordset

'作用:判断数据库是否正确连结
'自己可以更改连接串
Public Function GetConn()
Conn.Open "Provider=SQLOLEDB.1;Persist Security Info=False;User ID=sa;Initial Catalog=Northwind;Data Source=yang"
If Err.Number <> 0 Then
GetConn = False
Else
GetConn = True
End If
End Function

'根据输入的雇员ID,得到雇员的名称
Public Function GetEmployeeName(strEmployeeID As Integer) As String
Dim strSql As String
Set rs = New ADODB.Recordset
strSql = "select LastName+firstname from employees where EmployeeID=" & strEmployeeID
rs.Open strSql, Conn, adOpenStatic, adLockOptimistic
If rs.EOF Then
GetEmployeeName = ""
Else
GetEmployeeName = rs.Fields(0)
End If
rs.Close
End Function

‘'返回所有的雇员列表
Public Function GetEmployeeList() As ADODB.Recordset
Dim strSql As String
Set rs = New ADODB.Recordset
strSql = "select EmployeeID,LastName,FirstName,Title,TitleOfCourtesy,BirthDate,HireDate,Address,City from employees"
rs.CursorLocation = adUseClient
rs.Open strSql, Conn, adOpenStatic
Set GetEmployeeList = rs
'rs.Close
End Function

　　我们进行测试
　　新建ASP页面，”TestWebDb1.ASP”。主要用来测试GetEmployeeList()方法
<HEAD>
<!- 测试页 ->
<!- 功能：测试组件 ->
<!- 作者：龙卷风.NET ->
<%
Dim strTopic
Dim strTitle
Dim strContents
Dim DataQuery
Dim Rs
Dim Myself
Myself=Request.ServerVariables("script_name")
Set DataQuery=Server.CreateObject("WebDb.GetInfomation")
Set Rs=Server.CreateObject("adodb.recordset")
%>
<TITLE>数据组件测试页</TITLE>
<H1><CENTER>欢迎使用数据组件(www.knowsky.com)</CENTER></H1>
<%
Dim Flag
Flag=DataQuery.GetConn()
If Flag=false then
ResPonse.Write "数据库没有连结,请检查"
ResPonse.End
End if

Set Rs=DataQuery.GetEmployeeList()
if rs.eof then
Response.write "没有数据,请查询"
Response.end
end if

Rs.PageSize =3
Page= CLng(Request.QueryString ("Page"))
If Page < 1 Then Page = 1
If Page > Rs.PageCount Then Page = Rs.PageCount
Response.Write "<CENTER><TABLE BORDER=1 cellspacing=0 cellpadding=2>"
Response.Write "<tr BGCOLOR=silver align=center>"
Response.Write "<td>EmployeeID</TD>"
Response.Write "<td>LastName</td>"
Response.Write "<td>FirstName</td>"
Response.Write "<td>Title</a></td>"
Response.Write "<td>TitleOfCourtesy</a></td>"
Response.Write "<td>BirthDate</td>"
Response.Write "<td>HireDate</td>"
Response.Write "<td>Address</td>"
Response.Write "<td>City</td>"
Response.Write "</tr>"
Rs.AbsolutePage = Page
For iPage = 1 To Rs.PageSize
Response.Write "<TR align=right>"
for i=0 to Rs.fields.count-1
Response.Write "<td>"&Rs.fields.item(i)&"</td>"
next
Response.Write "</TR>"
Rs.MoveNext
If Rs.EOF Then Exit For
next
Response.Write "</TABLE></CENTER>"
%>
<Form name="myform" method="get">
<%If Page <> 1 Then%>
<A HREF=http://www.blue1000.com/article/"<%=Myself%>?Page=1">第一页</A>
<A HREF="<%=Myself%>?Page=<%=(Page-1)%>"></A>
<A HREF=http://www.blue1000.com/article/"<%=Myself%>?Page=<%=Rs.PageCount%>">最后的一页</A>
<%End If%>
页次:<FONT COLOR="Red"><%=Page%>/<%=Rs.PageCount%></FONT>
</Form>
<%Rs.close%>
　　新建ASP页面，”TestWebDb2.ASP”。主要用来测试GetEmployeeName()方法
　　这个页面相对简单一些
<HEAD>
<!- 测试页 ->
<!- 功能：测试组件 ->
<!- 作者：龙卷风.NET ->
<%
Dim DataQuery
Dim strID
Dim strResult
Set DataQuery=Server.CreateObject("WebDb.GetInfomation")
%>
<TITLE>数据组件测试页</TITLE>
<H1><CENTER>欢迎使用数据组件(www.knowsky.com)</CENTER></H1>
<%
If Len(Request.QueryString("ID")) > 0 Then
strID = Request.QueryString("ID")
Dim Flag
Flag=DataQuery.GetConn()
If Flag=false then
ResPonse.Write "数据库没有连结,请检查"
ResPonse.End
End if

strResult=DataQuery.GetEmployeeName(cint(strID))
if strResult="" then
Response.Write "对不起,没有这个编号,请查询"
Response.End
else
ResPonse.Write strResult
end if
End If
%>
<FORM NAME="MyForm">
<INPUT TYPE=TEXTBOX NAME="EmpID" SIZE=40><P>
<INPUT LANGUAGE="VBScript"
TYPE="BUTTON"
VALUE="Search"
ONCLICK="window.location.href = 'TestWebDb2.ASP?ID=' _
+ MyForm.EmpID.Value">
</FORM>
</HEAD>

　　一些想法:数据库连结如果放到组件里，如果要修改数据库连结，则要重新编译组件，可能会由此引发一些问题(但是推荐这种，毕竟数据库名和服务器名不会经常改)
　　如果数据库连结放到ASP页面，可以通过属性传值到组件中，但是安全性会降低。图文结合：http://www.qqread.com/asp/2006/10/u237265.html