Sets or returns the default value of a
Field object. For a
Field object not yet appended to the
Fields collection, this property is read/write (Microsoft Access workspaces only).
Syntax
expression .DefaultValue
expression A variable that represents a Field object.
Remarks
The setting or return value is a String data type that can contain a maximum of 255 characters. It can be either text or an expression. If the property setting is an expression, it can't contain user-defined functions, Microsoft Access database engine SQL aggregate functions, or references to queries, forms, or other Field objects.
Note
You can also set the DefaultValue property of a Field object on a TableDef object to a special value called "GenUniqueID( )". This causes a random number to be assigned to this field whenever a new record is added or created, thereby giving each record a unique identifier. The field's Type property must be Long. |
The availability of the DefaultValue property depends on the object that contains the Fields collection, as shown in the following table.
If the Fields collection belongs to an
| Then DefaultValue is
|
|---|
Index object
| Not supported
|
QueryDef object
| Read-only
|
Recordset object
| Read-only
|
Relation object
| Not supported
|
TableDef object
| Read/write
|
When a new record is created, the
DefaultValue property setting is automatically entered as the value for the field. You can change the field value by setting its
Value property.
The DefaultValue property doesn't apply to AutoNumber and Long Binary fields.
Example
This example uses the DefaultValue property to alert the user of a field's normal value while prompting for input. In addition, it demonstrates how new records will be filled using DefaultValue in the absence of any other input. The DefaultPrompt function is required for this procedure to run.
Sub DefaultValueX()
Dim dbsNorthwind As Database
Dim tdfEmployees As TableDef
Dim strOldDefault As String
Dim rstEmployees As Recordset
Dim strMessage As String
Dim strCode As String
Set dbsNorthwind = OpenDatabase("Northwind.mdb")
Set tdfEmployees = dbsNorthwind.TableDefs!Employees
' Store original DefaultValue information and set the
' property to a new value.
strOldDefault = _
tdfEmployees.Fields!PostalCode.DefaultValue
tdfEmployees.Fields!PostalCode.DefaultValue = "98052"
Set rstEmployees = _
dbsNorthwind.OpenRecordset("Employees", _
dbOpenDynaset)
With rstEmployees
' Add a new record to the Recordset.
.AddNew
!FirstName = "Bruce"
!LastName = "Oberg"
' Get user input. If user enters something, the field
' will be filled with that data; otherwise, it will be
' filled with the DefaultValue information.
strMessage = "Enter postal code for " & vbCr & _
!FirstName & " " & !LastName & ":"
strCode = DefaultPrompt(strMessage, !PostalCode)
If strCode <> "" Then !PostalCode = strCode
.Update
' Go to new record and print information.
.Bookmark = .LastModified
Debug.Print " FirstName = " & !FirstName
Debug.Print " LastName = " & !LastName
Debug.Print " PostalCode = " & !PostalCode
' Delete new record because this is a demonstration.
.Delete
.Close
End With
' Restore original DefaultValue property because this is a
' demonstration.
tdfEmployees.Fields!PostalCode.DefaultValue = _
strOldDefault
dbsNorthwind.Close
End Sub
Function DefaultPrompt(strPrompt As String, _
fldTemp As Field) As String
Dim strFullPrompt As String
' Ask user for new DefaultValue setting for the specified
' Field object.
strFullPrompt = strPrompt & vbCr & _
"[Default = " & fldTemp.DefaultValue & _
", Cancel - use default]"
DefaultPrompt = InputBox(strFullPrompt)
End Function