I have two tables - training categories and training records. I LEFT JOIN the two tables using the category name of the training which exists in both tables. The training records are for all employees. I want a two queries - one for all employee and one for individual employees - that will give me a set of records for all training categories and NULLs for the training record columns if they do not exist. A normal LEFT JOIN. I want to know all the trainings taken as well as those not taken.
However, I cannot get this to work, I believe because across all employees, all training categories have been accounted for. I do not get records with NULL columns for the training record. How can I correct this? Do I have to group?