Move 方法范例
内容
Move 方法范例
该范例使用 Move 方法定位基于用户输入的记录指针。
Public Sub MoveX()
Dim rstAuthors As ADODB.Recordset
Dim strCnn As String
Dim varBookmark As Variant
Dim strCommand As String
Dim lngMove As Long
' 打开 Authors 表的记录集。
strCnn = "Provider=sqloledb;" & _
"Data Source=srv;Initial Catalog=pubs;User Id=sa;Password=; "
Set rstAuthors = New ADODB.Recordset
rstAuthors.CursorType = adOpenStatic
' 使用客户端游标以允许使用 AbsolutePosition 属性。
rstAuthors.CursorLocation = adUseClient
rstAuthors.Open "SELECT au_id, au_fname, au_lname, city, state " & _
"FROM Authors ORDER BY au_lname", strCnn, , , adCmdText
rstAuthors.MoveFirst
Do While True
' 显示有关当前记录的信息并询问要移动的记录数。
strCommand = InputBox( _
"Record " & rstAuthors.AbsolutePosition & _
" of " & rstAuthors.RecordCount & vbCr & _
"Author: " & rstAuthors!au_fname & _
" " & rstAuthors!au_lname & vbCr & _
"Location: " & rstAuthors!City & _
", " & rstAuthors!State & vbCr & vbCr & _
"Enter number of records to Move " & _
"(positive or negative).")
If strCommand = "" Then Exit Do
' 保存书签以防 Move 向前或向后移动太远。
varBookmark = rstAuthors.Bookmark
' Move 方法需要数据类型为长整型的参数。
lngMove = CLng(strCommand)
rstAuthors.Move lngMove
' 捕获 BOF 或 EOF。
If rstAuthors.BOF Then
MsgBox "Too far backward! " & _
"Returning to current record."
rstAuthors.Bookmark = varBookmark
End If
If rstAuthors.EOF Then
MsgBox "Too far forward! " & _
"Returning to current record."
rstAuthors.Bookmark = varBookmark
End If
Loop
rstAuthors.Close
End Sub
VBScript 版本
下面是使用 VBScript 编写、并用于 Active Server Page (ASP) 的相同范例。如需查看该完整功能范例，请使用与 IIS 一同安装并位于 C:\InetPub\ASPSamp\AdvWorks 的数据源 AdvWorks.mdb，来创建名为 AdvWorks 的系统“数据源名称”(DSN)。这是 Microsoft Access 数据库文件。请使用查找命令定位文件 Adovbs.inc，并将其放入计划使用的目录中。请将以下代码剪切并粘贴到记事本或其他文本编辑器中，另存为“Move.asp”。这样，便可在任何客户端浏览器中查看结果。
请输入字母或非整数查看错误处理的运作。
<!-- #Include file="ADOVBS.INC" -->
<% Language = VBScript %>
<HTML><HEAD>
<TITLE>ADO Move Methods</TITLE></HEAD>
<BODY>
<FONT FACE="MS SANS SERIF" SIZE=2>
<Center>
<H3>ADO Move Methods</H3>
<%
' 创建并打开 Connection 对象。
Set OBJdbConnection = Server.CreateObject("ADODB.Connection")
OBJdbConnection.Open "AdvWorks"
' 创建并打开 Recordset 对象。
Set RsCustomerList = Server.CreateObject("ADODB.Recordset")
RsCustomerList.ActiveConnection = OBJdbConnection
RsCustomerList.CursorType = adOpenKeyset
RsCustomerList.LockType = adLockOptimistic
RsCustomerList.Source = "Customers"
RsCustomerList.Open
' 检查该会话中用户移动的数目，以窗体中的数量作为增量。
Session("Clicks") = Session("Clicks") + Request.Form("MoveAmount")
Clicks = Session("Clicks")
' 移动到上次已知的记录集位置加上由 Form Post 方法传递的数量。
RsCustomerList.Move CInt(Clicks)
' 出错处理。
If RsCustomerList.EOF Then
Session("Clicks") = RsCustomerList.RecordCount
Response.Write "This is the Last Record"
RsCustomerList.MoveLast
Else If RsCustomerList.BOF Then
Session("Clicks") = 1
RsCustomerList.MoveFirst
Response.Write "This is the First Record"
End If
End If
%>
<H3>Current Record Number is <BR>
<% If Session("Clicks") = 0 Then
Session("Clicks") = 1
End If
Response.Write(Session("Clicks") )%> of <%=RsCustomerList.RecordCount%></H3>
<HR>
<Center><TABLE COLSPAN=8 CELLPADDING=5 BORDER=0>
<!-- Customer 表的 BEGIN 列标头行 -->
<TR>
<TD ALIGN=CENTER BGCOLOR="#008080">
<FONT STYLE="ARIAL NARROW" COLOR="#ffffff" SIZE=1>Company Name</FONT>
</TD>
<TD ALIGN=CENTER BGCOLOR="#008080">
<FONT STYLE="ARIAL NARROW" COLOR="#ffffff" SIZE=1>Contact Name</FONT>
</TD>
<TD ALIGN=CENTER WIDTH=150 BGCOLOR="#008080">
<FONT STYLE="ARIAL NARROW" COLOR="#ffffff" SIZE=1>Phone Number</FONT>
</TD>
<TD ALIGN=CENTER BGCOLOR="#008080">
<FONT STYLE="ARIAL NARROW" COLOR="#ffffff" SIZE=1>City</FONT>
</TD>
<TD ALIGN=CENTER BGCOLOR="#008080">
<FONT STYLE="ARIAL NARROW" COLOR="#ffffff" SIZE=1>State/Province</FONT>
</TD>
</TR>
<!-- 显示 Customer 表的 ADO 数据 -->
<TR>
<TD BGCOLOR="f7efde" ALIGN=CENTER>
<FONT STYLE="ARIAL NARROW" SIZE=1>
<%= RSCustomerList("CompanyName")%>
</FONT></TD>
<TD BGCOLOR="f7efde" ALIGN=CENTER>
<FONT STYLE="ARIAL NARROW" SIZE=1>
<%= RScustomerList("ContactLastName") & ", " %>
<%= RScustomerList("ContactFirstName") %>
</FONT></TD>
<TD BGCOLOR="f7efde" ALIGN=CENTER>
<FONT STYLE="ARIAL NARROW" SIZE=1>
<%= RScustomerList("PhoneNumber")%>
</FONT></TD>
<TD BGCOLOR="f7efde" ALIGN=CENTER>
<FONT STYLE="ARIAL NARROW" SIZE=1>
<%= RScustomerList("City")%>
</FONT></TD>
<TD BGCOLOR="f7efde" ALIGN=CENTER>
<FONT STYLE="ARIAL NARROW" SIZE=1>
<%= RScustomerList("StateOrProvince")%>
</FONT></TD>
</TR> </Table></FONT>
<HR>
<Input Type = Button Name = cmdDown Value = "< ">
<Input Type = Button Name = cmdUp Value = " >">
<H5>Click Direction Arrows for Previous or Next Record
<BR> Click Move Amount to use Move Method
Enter Number of Records to Move + or - </H5>
<Table>
<Form Method = Post Action="Move.asp" Name=Form>
<TR><TD><Input Type="Button" Name = Move Value="Move Amount "></TD><TD></TD><TD>
<Input Type="Text" Size="4" Name="MoveAmount" Value = 0></TD><TR>
</Form></Table></Center>
</BODY>
<Script Language = "VBScript">
Sub Move_OnClick
' 确认输入的移动值为整型。
If IsNumeric(Document.Form.MoveAmount.Value)Then
Document.Form.MoveAmount.Value = CInt(Document.Form.MoveAmount.Value)
Document.Form.Submit
Else
MsgBox "You Must Enter a Number", ,"ADO-ASP Example"
Document.Form.MoveAmount.Value = 0
End If
End Sub
Sub cmdDown_OnClick
Document.Form.MoveAmount.Value = -1
Document.Form.Submit
End Sub
Sub cmdUp_OnClick
Document.Form.MoveAmount.Value = 1
Document.Form.Submit
End Sub
</Script>
</HTML>