Microsoft KB Archive/143263

= How To Use an RDO Prepared Statement to Find a Single Record =

Article ID: 143263

Article Last Modified on 7/13/2004

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APPLIES TO


 * Microsoft Visual Basic 6.0 Learning Edition
 * Microsoft Visual Basic 6.0 Professional Edition
 * Microsoft Visual Basic 6.0 Enterprise Edition
 * Microsoft Visual Basic 5.0 Enterprise Edition
 * Microsoft Visual Basic 4.0 32-Bit Enterprise Edition

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This article was previously published under Q143263



SUMMARY
RDO does not have a FindFirst or a Seek method and in many cases as a programmer you need to find out if a particular record exists or not. This sample uses an RDO prepared statement to provide this kind of functionality. The following code allows the user to type in a field they would like to search on (for instance, OrderID, PONum, LastName), click on a command button and then see a message box with the result of the query. This example will only find the first occurrence of what you are searching for. You may also want to use a stored procedure once you know that your query is working the way that you want it to. Keep in mind that RDO is available in Visual Basic 4.0 32-bit and Visual Basic 5.0 Enterprise Editions only.



Step-By-Step Example
 Start a new project in Visual Basic. Form1 is created by default. Add a CommandButton and a text box. Accept the default names for all. Make sure a reference to the Microsoft Remote Data Object library has been established. In Visual Basic 4.0, you can establish the reference by clicking References from the Tools menu. In Visual Basic 5.0, click References from the Project menu.  Add the following code to the General Declarations section of Form1: Option Explicit Dim ps As rdoPreparedStatement ' Dim as rdoQuery   rdoquery replace PreparedStatement ' in VB5 and VB6 Dim conn As rdoConnection Dim rs As rdoResultset

Private Sub Form_Load With rdoEnvironments(0) .CursorDriver = rdUseOdbc Set conn = .OpenConnection("", rdDriverNoPrompt, False, _             "driver={SQL Server};              server=Myserver;uid=MyUID;pwd=Mypwd;database=pubs") End With Set ps = conn.CreatePreparedStatement("", _      '   CreateQuery replaces CreatePreparedStatement in VB5 and VB6       '   Set ps = conn.CreateQuery("", _ "select au_lname from authors where au_lname = ?")     End Sub

Private Sub Command1_Click ps.rdoParameters(0) = Text1.Text If rs Is Nothing Then Set rs = ps.OpenResultset(rdOpenKeyset) Else rs.Requery End If         If Not rs.EOF Then Msgbox rs!au_lname Else Msgbox "No record match." End If     End Sub

Private Sub Form_Unload(Cancel As Integer) rs.Close ps.Close conn.Close End Sub

 Make sure you have an appropriate ODBC data source, user ID, and password, then press F5 to run the program. Type your search criteria in Text1 (for example, "White"), and click the CommandButton. A message box will appear with either the record you are searching for if there is a match, or with a message "No record match" if there is no match.

Keywords: kbhowto kbrdo KB143263

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