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MS Access Forum / Forms Programming / November 2006Validation Rule
I have setup a validation rule of Not "" but it still allows the form to be saved even though the field has been left empty?? Any Suggestions? Many Thanks S >I have setup a validation rule of Not "" but it still allows the form to be >saved even though the field has been left empty?? [quoted text clipped - 4 lines] > >S Set the field's Required property to true instead. "" is a String value, a zero length string. NULL is a *different* value, or better non-value. A field that is NULL is undefined, empty, unspecified; "" is defined, non-empty, specified - you know exactly what it is, it's a zero length string. Setting a field as Required in a table will prohibit saving a record where that field is NULL. Note that if you also set the Allow Zero Length String property to Yes (it's No by default), you can have "" as a valid, non-NULL value; this combination should be used with great caution and only when needed, since it's very hard to tell a NULL from a zero-length string! John W. Vinson[MVP] If a field is empty, it has a value of Null which is not the same thing as "". > I have setup a validation rule of Not "" but it still allows the form to be > saved even though the field has been left empty?? [quoted text clipped - 4 lines] > > S >I have setup a validation rule of Not "" but it still allows the form to be >saved even though the field has been left empty?? Check the table field's Required property. This prevents Null values from being saved. I think you want this set to Yes. This translates to the validation rule Is Not Null. Check the table field's AllowZeroLength property. This prevents empty string values from being saved. It sounds like you want this property set to No. I think this corresponds to a validation rule similar to <> ""  SignatureMarsh MVP [MS Access] Marshall, I have checked the fields required porperty to yes and allow zero length property to no but the problem I seem to have now is its not very user friendly with regards to the message which is presented to the user when they forget to complete the field eg The field 'tblcustomers.title' cannot contain a null value because the required property for this field is set to true, Enter a value in this field. The system then asks be to close the form anyway and I select no and get an action failed dialogue message. Does anyone have any suggestions? >>I have setup a validation rule of Not "" but it still allows the form to >>be [quoted text clipped - 8 lines] > like you want this property set to No. I think this > corresponds to a validation rule similar to <> "" You can trap those errors using the form's Error event: Private Sub Form_Error(DataErr As Integer, Response As Integer) Select Case DataErr Case 3314 MsgBox "You must specify ..." Response = acDataErrContinue Case 3315 MsgBox "You can not use an empty ..." Response = acDataErrContinue End Select End Sub OTOH, if that's not the approach you want to take, you can allways use the validation rules I posted earlier. I wouldn't bother with the zero length string rule because a user would have to type "" to enter a ZLS. SignatureMarsh MVP [MS Access] >I have checked the fields required porperty to yes and allow zero length >property to no but the problem I seem to have now is its not very user [quoted text clipped - 18 lines] >> like you want this property set to No. I think this >> corresponds to a validation rule similar to <> "" |
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