> On 12 Jun 2021, at 10:00, Condor <condor@xxxxxxxxxx> wrote: > > select qw.*, case whem length(qw.mm) > 0 THEN COALESCE(SUBSTRING(qw.mm, 1, 1), '') ELSE qw.mm END AS qw.mm A little off-topic, but isn’t that a roundabout way of writing just this?: select qw.*, coalesce(substring(qw.mm, 1, 1), '') as mm Or even: select qw.*, coalesce(left(qw.mm, 1), '') as mm Regards, Alban Hertroys -- There is always an exception to always.