How to Prevent Duplicate mobile from being entered into table ...

[uronmapu]

I have a tblContacts table including the fields: ID, Full Name, Mobile (format text)

And a NewContact form including the textboxs: ID, Full Name, Mobile

How to Prevent Duplicate mobile from being entered into NewContacts form ...

I'm using the code below:

DLookUp("[Mobile]","tblContacts","[Mobile] = '" &  [Forms]![NewContact]![Mobile] & "' and [CustID] <>" &  [Forms]![NewContact]![ID]) Is Null

but have error message:






Or: (but error the sames)

1. In the Navigation Pane, right-click the table that contains the field, and then click Design View.
2. Select the field that you want to make sure has unique values.
3. In the Field Properties pane, on the General tab, set the Indexed property to Yes (No duplicates).

Many thanks,

[orange]

I have a tblContacts table including the fields: ID, Full Name, Mobile (format text)

And a NewContact form including the textboxs: ID, Full Name, Mobile

How to Prevent Duplicate mobile from being entered into NewContacts form ...

I'm using the code below:

DLookUp("[Mobile]","tblContacts","[Mobile] = '" &  [Forms]![NewContact]![Mobile] & "' and [CustID] <>" &  [Forms]![NewContact]![ID]) Is Null

but have error message:



Remove the " from the validation rule
Or: (but error the sames)

1. In the Navigation Pane, right-click the table that contains the field, and then click Design View.
2. Select the field that you want to make sure has unique values.
3. In the Field Properties pane, on the General tab, set the Indexed property to Yes (No duplicates).

Many thanks,

Show us the details for the field MOBILE - that's what has to have no duplicates.

[uronmapu]

Done

Code:

DLookUp("[Mobile]","tblNames","[Mobile] = '" & [Forms]![frmNewContact]![text4] & "'") Is Null