PRB: Error Setting Field Format Property of Access Tables (190522)


The information in this article applies to:

  • Microsoft Visual Basic Standard Edition, 32-bit, for Windows 4.0
  • Microsoft Visual Basic Professional Edition, 32-bit, for Windows 4.0
  • Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows 4.0
  • Microsoft Visual Basic Learning Edition for Windows 5.0
  • Microsoft Visual Basic Learning Edition for Windows 6.0
  • Microsoft Visual Basic Professional Edition for Windows 5.0
  • Microsoft Visual Basic Professional Edition for Windows 6.0
  • Microsoft Visual Basic Enterprise Edition for Windows 5.0
  • Microsoft Visual Basic Enterprise Edition for Windows 6.0
This article was previously published under Q190522

SYMPTOMS

From Visual Basic, when trying to specify a field Format property of an Access table (for example, field type DateTime) from blank to "Long Date" format, the following error occurs:
Run-time error '3421':

Data type conversion error.

CAUSE

The property data type constant should always be "dbText." If other data type constants, such as dbDate or dbNumeric are specified, you will encounter the error described above.

STATUS

This behavior is by design.

MORE INFORMATION

The following Visual Basic 5.0 example creates a new field object MyNewDate with data type dbDate, and appends it to the Fields collection. It then specifies the Format property with the value "Long Date." Note that the Format property is specified as "dbDate," which is incorrect. To correct the problem, you should change: 
   Set prp = fld.CreateProperty("Format", dbDate)
to: 
    Set prp = fld.CreateProperty("Format", dbText)

Steps to Reproduce Behavior

  1. Start a "Standard EXE" project in Visual Basic. Form1 is created by default.
  2. From the Project menu, select References, and then place a check next to Microsoft DAO 3.5 Object Library.

    In Visual Basic 4.0, you can reference Microsoft DAO Object Library from Tools menu, then select References.
  3. Add a CommandButton control, Command1, to Form1.
  4. Paste the following code in the Command1_Click() code snippet: 
          Dim db As Database
      Dim tdf As TableDef
      Dim fld As Field
      Dim prp As Property
      
      Set db = OpenDatabase("Nwind.mdb")
      Set tdf = db.TableDefs("Employees")
      tdf.Fields.Append tdf.CreateField("MyNewDate", dbDate) 'Error line
      Set fld = tdf.Fields("MyNewDate")
      Set prp = fld.CreateProperty("Format", dbDate)
      prp.Value = "Long Date"
      fld.Properties.Append prp

REFERENCES

For more information please reference the following articles:

170549 HOWTO: Read or Modify User-Defined DAO Properties

178745 ACC: Using DAO to Set and Retrieve Custom Data Properties

Modification Type:MinorLast Reviewed:7/15/2004
Keywords:kbprb KB190522
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