SQL-Abfrage, um Daten nur zurückzugeben, wenn ALLE erforderlichen Spalten vorhanden und nicht NULL sind

Sie können exists verwenden . Ich denke, Sie beabsichtigen:

select t.*
from t
where exists (select 1
              from t t2
              where t2.id = t.id and t2.type = 'Purchase' and t2.total is not null
             ) and
      exists (select 1
              from t t2
              where t2.id = t.id and t2.type = 'Exchange' and t2.total is not null
             ) and
      exists (select 1
              from t t2
              where t2.id = t.id and t2.type = 'Return' and t2.total is not null
             );

Es gibt Möglichkeiten, dies zu "vereinfachen":

select t.*
from t
where 3 = (select count(distinct t2.type)
           from t t2
           where t2.id = t.id and
                 t2.type in ('Purchase', 'Exchange', 'Return') and
                 t2.total is not null
          );