You are mixing implicit joins and explicit joins. A simple rule: don't use commas in from
clauses.
SELECT h.hoursworked, p.projectname, p.description, p.archive, c.clientname
FROM hours h join
projects p
on h.projectid = p.projectid join
clients c
ON p.clientid = c.clientid
WHERE p.archive = 0;
In addition, the syntax for using aliases is <table alias>
.<column alias>
, not the other way around.