Hi, Exists function accepts only one field on the source table and not composite keys.
If you want to check existence on more than 1 field, you will need to make a key field from a concatenation of these fields. For example in your case:
[student_data]: LOAD stud_id & '-' & stud_name as stud_key, *; select <some records> from student a inner join school b on a.stud_id = b.stud.id and a.stud_name = b.stud_name where b.date_time > 'lastexectime';
Load * from Test.qvd where not exists(stud_key);
Of course the qvd file should contain the same stud_key field.
Hope this helps!
Vu Nguyen If a post helps resolve your issue, please mark the answer as correct.