ACC: Setting DAO Required Property Against SQL Server Fails Silently

ID: Q200407


The information in this article applies to:
  • Microsoft Access versions 2.0, 7.0, 97

Advanced: Requires expert coding, interoperability, and multiuser skills.


SYMPTOMS

When you use Data Access Objects (DAO) to set the Required property of a field in a SQL Server table, the attempt fails silently.


RESOLUTION

Instead of using DAO, execute Data Definition Language (DDL) statements from a SQL pass-through query to create a table with columns that do not allow Null values.

Note the following sample DDL statement, which creates a table named tblTest with one field named F1. The F1 field does not accept Null values:


   CREATE TABLE "tblTest" ("F1" varchar(50) NOT NULL) 


STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article.


MORE INFORMATION

Steps to Reproduce Behavior

  1. Create a new blank database named TestDatabase.


  2. Create a module, and type the following line in the Declarations section if it is not already there:


  3. 
    Option Explicit 
  4. Type the following procedure:
     
    Sub CreateSQLServerTable()
    
        Dim db As Database
        Dim td As TableDef
        Dim f As Field
    
        'Open connection to server, assuming the server
        'is running on the same machine that we run the
        'code on:
    
        Set db = OpenDatabase("", False, False, _
        "ODBC;DSN=LocalServer;UID=sa;PWD=;DATABASE=Pubs;")
    
        'Create a table and its field, setting the properties
        'of the field
    
        Set td = db.CreateTableDef("tblTest")
        Set f = td.CreateField("F1", dbText, 50)
        f.AllowZeroLength = False
        f.Required = True
        td.Fields.Append f
        db.TableDefs.Append td
    
        MsgBox "Table Added. The required property was set to: " & _
        vbCrLf & f.Required & vbCrLf & "Reading Table..."
    
        'Clean up
        Set f = Nothing
        Set td = Nothing
        db.Close
        Set db = Nothing
    
        'Reopen the connection to SQL Server
        Set db = OpenDatabase("", False, False, _
        "ODBC;DSN=LocalServer;UID=sa;PWD=;DATABASE=Pubs;")
    
        'Examine the F1 field
    
        Set td = db.TableDefs("tblTest")
        Set f = td.Fields("F1")
    
        MsgBox "The required property for column F1 is set to: " & _
        f.Required
    
    End Sub 
    NOTE: You may need to change the values for the UID (user name) and PWD (password) parameters in the example above to successfully connect to SQL Server. If necessary, ask your database administrator for a user name and password with permissions to create tables.


  5. In the Debug window, type the following and press ENTER:


  6. 
    Call CreateSQLServerTable 
  7. Note that when you run the procedure, the Required property for the F1 field is initially set to True when the table is created. However, when the procedure re-examines the F1 field, the original setting for the Required property has been lost, and returns False.



REFERENCES

For more information about creating pass-through queries in Microsoft Access 97, type the following line in the Microsoft Office Assistant: "Send commands to an SQL database using a pass-through query."

For more information about creating pass-through queries in Microsoft Access 95, type the following line the Microsoft Access 95 Answer Wizard: "Send commands to an SQL database using a pass-through query."

For more information about creating pass-through queries in Microsoft Access 2.0, Click Help, and then Search. Click the Index tab, and type "pass-through query."

Additional query words: pra

Keywords : kbdta
Version : WINDOWS:2.0,7.0,97
Platform : WINDOWS
Issue type : kbbug


Last Reviewed: September 17, 1999
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