Question

I have two MySQL queries.

The first shows what training has been done by a person. The second shows what training is required for a job.

First query

select training from coursescompleted where person='$person'

Second query

select j.job, r.training from riskstraining r join jobsrisks j on j.risk=r.Risk

As an example, the output of the first query (training completed) is:

first aid course
Firesystems course

And the output of the second query (training needed) is:

Security Guard   -   Firesystems Course
Crane Operator   -   Driving LicenseCourse
Crane Operator   -   first aid course

How do I combine these queries to show what courses are required in order to do a job? As per the example below, if I chose the job ‘crane operator’, the result should be ‘Driving License Course’ as the person has already completed the ‘first aid course’. A join will show the results where they match, not where they don’t match.

Desired output – where ‘crane operator’ is chosen

crane operator   -   driving license course

Any advice or guidance on what the query should be?

Answer 1

select j.job, r.training from riskstraining r join jobsrisks j on j.risk=r.Risk
where r.training not in 
(select training from coursescompleted where person='$person')

something like that I guess.