Anyway I am trying to compare two tables of data against one another and display the differences to the user, which I was somewhat successful using a LEFT JOIN query.

However I need it to be user specific so that it only compares the data from the table that is from one specific user (as multiple users use the same database to store their information). I have looked through some other close example but have found nothing that works, a sample of the code is here:

"SELECT DISTINCT table1.*
FROM `table1` table1
LEFT JOIN `table2` table2 ON table1.PIC = table2.PIC
WHERE table2.PIC IS NULL";

Any help would be greatly appreciated :)