Sets or returns a value that indicates whether a
Field object requires a non-Null value.
Syntax
expression .Required
expression A variable that represents a Field object.
Remarks
For a Field not yet appended to the Fields collection, this property is read/write.
The availability of the
Required property depends on the object that contains the
Fields collection, as shown in the following table.
If the Fields collection belongs to a
| Then Required is
|
|---|
Index object
| Not supported
|
QueryDef object
| Read-only
|
Recordset object
| Read-only
|
Relation object
| Not supported
|
TableDef object
| Read/write
|
You can use the
Required property along with the
AllowZeroLength,
ValidateOnSet, or
ValidationRule property to determine the validity of the
Value property setting for that
Field object. If the
Required property is set to
False, the field can contain
null values as well as values that meet the conditions specified by the
AllowZeroLength and
ValidationRule property settings.
Note
When you can set this property for either an Index object or a Field object, set it for the Field object. The validity of the property setting for a Field object is checked before that of an Index object.
|
Example
This example uses the Required property to report which fields in three different tables must contain data in order for a new record to be added. The RequiredOutput procedure is required for this procedure to run.