PRB: Run-time Error '40002' When Querying on s_GUID field in RDO

• Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0

SYMPTOMS

When using the database replication feature of Microsoft Access, a ReplicationID AutoNumber field is added to the database. The ReplicationID AutoNumber field (s_GUID) is a 16-byte GUID (Globally Unique Identifier) that uniquely identifies each record in the database.

If you are using RDO 2.0 to access the replicated database and you try to search on the s_GUID field using the following syntax:

   Set rdoRes = rdoConn.OpenResultset("select * from Nwind where
   s_guid={guid{9B83B027-E038-11D1-847E-00C04FB1784E}}", _
   rdOpenKeyset, rdConcurLock, rdAsyncEnable) 

   Run-Time error '40002':

   37000: [Microsoft][ODBC Microsoft Access 97 Driver] Syntax error
   (missing operator) in query expression 's_guid = guid
   9B83B027-E038-11D1-847E-00C04FB1784E}'. 

CAUSE

Because ODBC defines the curly brace as an escape code for vendor specific escape clauses, you must turn off escape clause scanning when you use literal globally unique identifiers (GUIDs) in SQL statements with the Microsoft Access ODBC Driver. This is accomplished by using the SQLSetConnectionOption API to turn off driver scanning for escape clauses.

STATUS

This behavior is by design.

MORE INFORMATION

Here is an example:

1. Create a new form in Visual Basic. Form1 is created by default.



2. From the Project menu, point to References then select Microsoft Remote Data Object 2.0 in the References dialog box.



3. Add a Command Button to the form.



4. Add the following to the General Declaration section of the form:

   
         Private Sub Command1_Click()
         Dim rdoConn As rdoConnection
         Dim rdoRes As rdoResultset
         Dim strguid As String
   
         'Make sure that you are pointing to a valid DSN and a replicated
         'database.
         Set rdoConn = rdoEnvironments(0).OpenConnection("", _
                 rdDriverNoPrompt, _
                 False, "DRIVER={Microsoft Access Driver (*.mdb)};" & _
                 "dsn=acc2;UID=admin;PWD=;")
   
         'Change this so that it points to a valid GUID in your replicated
         'database.
         strguid = "{guid {9B83B027-E038-11D1-847E-00C04FB1784E}}"
   
         'Comment this line and you will see the previously noted error.
         SQLSetConnectOption rdoConn.hdbc, SQL_NOSCAN, SQL_NOSCAN_ON
   
         Set rdoRes = rdoConn.OpenResultset("select *  from customers " & _
                 "where s_guid = " & strguid, rdOpenKeyset, rdConcurLock)
   
         Debug.Print rdoRes!CompanyName
   
         rdoRes.Close
         rdoConn.Close
         End Sub 




5. Add a new module to the form. Module1 is created by default.



6. Add the following code to the General Declaration section of the Module:

   
         Option Explicit
         Public Const SQL_NOSCAN = 2
         Public Const SQL_NOSCAN_OFF = 0
         Public Const SQL_NOSCAN_ON = 1
   
        Declare Sub SQLSetConnectOption Lib "odbc32.dll" (ByVal hdbc As Long,
        ByVal p1 As Long,   ByVal p2 As Long) 




7. Run the application. The value of the Company Name field should be displayed in the Immediate window.

REFERENCES

For additional information, please see the following article in the Microsoft Knowledge Base:

Q170117 HowTo: Use GUID Fields in Access from Visual C++

Additional query words:

Keywords : kbRDO kbVBp kbVBp500 kbVBp600 kbGrpVBDB
Version : WINDOWS:5.0,6.0
Platform : WINDOWS
Issue type : kbprb