AllowZeroLength Property
You can use the AllowZeroLength property to specify whether a zero-length string (" ") is a valid entry in a table field.
Note The AllowZeroLength property applies only to Text, Memo, and Hyperlink table fields.
Setting
The AllowZeroLength property uses the following settings.
| Setting | Visual Basic | Description |
|---|---|---|
| Yes | True | A zero-length string is a valid entry. |
| No | False | (Default) A zero-length string is an invalid entry. |
You can set this property by using the table's property sheet or Visual Basic.
Note To access a field's AllowZeroLength property by using Visual Basic, use the DAO AllowZeroLength property or the ADO Column.Properties("Set OLEDB:Allow Zero Length") property.
Remarks
If you want Microsoft Access to store a zero-length string instead of a Null value when you leave a field blank, set both the AllowZeroLength and Required properties to Yes.
The following table shows the results of combining the settings of the AllowZeroLength and Required properties.
| AllowZeroLength | Required | User's action | Value stored |
|---|---|---|---|
| No | No | Presses ENTER Presses SPACEBAR Enters a zero-length string |
Null Null (not allowed) |
| Yes | No | Presses ENTER Presses SPACEBAR Enters a zero-length string |
Null Null Zero-length string |
| No | Yes | Presses ENTER Presses SPACEBAR Enters a zero-length string |
(not allowed) (not allowed) (not allowed) |
| Yes | Yes | Presses ENTER Presses SPACEBAR Enters a zero-length string |
(not allowed) Zero-length string Zero-length string |
Tip You can use the Format property to distinguish between the display of a Null value and a zero-length string. For example, the string "None" can be displayed when a zero-length string is entered.
The AllowZeroLength property works independently of the Required property. The Required property determines only whether a Null value is valid for the field. If the AllowZeroLength property is set to Yes, a zero-length string will be a valid value for the field regardless of the setting of the Required property.