>select t1.* from table1 t1 where t1.key not in (select t2.key from table2 t2)>If your definition of existing is based on multiple fields, you can concatenate them in your subquery.
>select * from table1 t1 where t1.field1+t1.field2+t1.field3 not in ; > (select t2.field1+t2.field2+t2.field3 from table2 t2)>If the fields are not the same datatype, you can use transform() to convert them to character.