Help tuning a very poor SQL query

[eluser]jedd[/eluser]
Okay .. rough draft absent further understanding is this:

Code:

SELECT *
    FROM kg_compounds
    LEFT JOIN kg_progress ON kg_progress.compound=kg_compounds.id
    WHERE grade='$level'
    AND kg_progress.compound_progress=1

UNTESTED, mind. Perhaps something for you to start playing with, at least.

Can I suggest that for foreign keys - for example your kg_progress.compound - that you call them the other table name with a _id suffix.

So rather than kg_progress.compound you'd call it kg_progress.compound_id

I'd also suggest that you try to avoid having column names that are the same as table names - it's just plain confusing, and hints at a badly considered / designed schema. Often renaming the column as 'name' or 'description' is sufficiently descriptive.