Not enough info.  Please post your entire expression.  That error indicates you are likely missing a quote, parenthesis, or something similar.

Private Sub Form_BeforeUpdate(Cancel As Integer)

    DoCmd.RunSQL "INSERT INTO DataBaseChangeLogT SELECT * FROM DataBaseT " & _
         "WHERE MemberID=" & MemberID


End Sub

Good day

I followed the 2 line code in the above video and made changes according to my Tables/needs. I however get the following Error Message: Run-time error "3075": Syntax error(Missing Operator)in query expression 'MemberID='.(In my Tables, I don't work with Customers, but with Members. Thus my ID field is "MemberID".)

Kind regards

Lance

*EXPRESSION:
Private Sub Form_BeforeUpdate(Cancel As Integer)

    DoCmd.RunSQL "INSERT INTO DataBaseChangeLogT SELECT * FROM DataBaseT " & _
         "WHERE MemberID=" & MemberID


End Sub

Is MemberID coming from a form field? Sounds like a Null is being sent rather than an actual value.

The MemberID, is the Primary Key Field in my "DataBaseT" Table.

Oops! The MemberID, is also my Primary Key Field in my "DataBaseChangeLogT" Table.(The MemberID is thus the Primary Key Field in BOTH the DataBaseT and DataBaseChangeLogT Tables.)