SQL different query

[lenny6582]

I need to perform a mySQL query that returns data from one table that is not present in another. Basically I would normally use a nested query as below:

SELECT courseName
FROM tblCourses
WHERE courseID <> (SELECT courseID
FROM tblLnkCourses
WHERE studentID = xx)

This will basically tell me which courses a given student is NOT listed on. How would I convert this into a PHP MySQL query as I can't use nested queries?

Thanks for your help
Richard

[inerte]

SELECT tblCourses.courseName
FROM tblCourses
LEFT JOIN tblLnkCourses ON tblCourses.courseID = tblLnkCourses.courseID
WHERE tblLnkCourses.studentID = XX
AND tblLnkCourses.courseID IS NULL

I think... 🙂

[cornercuttinjoe]

why cant you use nested queries?

$query = "SELECT courseName FROM tblCourses WHERE courseID != some (SELECT courseID FROM tblLnkCourses WHERE studendID = '$student_id')";
$result = @($query);

this should do it, i think. try it and post what you get.