• declare @myTab table( ExtRef varchar(9), IntRef decimal(38,19))

    insert into @myTab(ExtRef,IntRef) values ('1',0)

    insert into @myTab(ExtRef,IntRef) values ('2.1',0)

    insert into @myTab(ExtRef,IntRef) values ('A',0)

    update @myTab

    set IntRef = case when isnumeric(ExtRef) = 1 then ExtRef else -1

    --(A)

    end

    update @myTab

    set IntRef = case when isnumeric(ExtRef) = 1 then ExtRef else -1

    --(A)

    end

    Confused here --(A) is a comment, yes?

    The cast to decimal would be required otherwise a failure converting varchar to decimal.

    Jamie