General developer forum

Yes, your problem is that it is too simple

What you have got is just a plain PHP array. The array keys are the first column of your results set, which seems to be id, and the values are plain objects with one field for each column.

So you can do

$records = get_records_sql(...);
foeach ($records as $id => $record) {
echo $record->id, record->prereq_course_id, record->prereq_quiz_id, record->prereq_grade;
}

if this is a condition:

 inner join {$CFG->prefix}user p on c.userid = p.id 

then, why return both ("c.userid" and "p.id") in the SELECT clause? I think you can delete "p.id" safely from there, as you have that info also available in the "c.userid" column.

Anyway, as a general solution, you can always use column aliases and name that column as you want. Just replace "p.id" in the SELECT clause by "p.id AS newnameforcolumn" and you'll get results properly in the "newnameforcolumn" field of the result records.

Duplicate columns names won't work in some DBs at all (mainly because Moodle uses "named" references to them both in "get_recordsXXX() and get_recordsetXXX() functions instead of "indexed" references), so avoid them completely (or use the aliases) in the SELECT clause if you want to avoid "misterious" problems like "id suplantation" or other undesired effects.

My 2 cents, ciao