id|score|last_name 1|11|smith 2|22|jones 3|33|smith 4|44|jones
Query we are pretending is valid is: SELECT id, last_name FROM table GROUP BY last_name;
What rows are returned? I expect to see something like:
?|?|smith ?|?|jones
However, what ? is isn't clear. Could we get a row like 1|33|smith ?
In SQL, all selected columns must be part of the group by or inside an aggregate.
id|score|last_name 1|11|smith 2|22|jones 3|33|smith 4|44|jones
Query we are pretending is valid is: SELECT id, last_name FROM table GROUP BY last_name;
What rows are returned? I expect to see something like:
?|?|smith ?|?|jones
However, what ? is isn't clear. Could we get a row like 1|33|smith ?
In SQL, all selected columns must be part of the group by or inside an aggregate.