Question

I need to get empolyees info from employees table, and their total wages from two different tables.

The SQL is approximately like this, but I don’t really know how to use joins to do this:

• CONCAT(first_name, ' ', last_name) from employees as e
• Sum(hours*pay) where date is "THIS MONTH" and employee_id = e.id from taxed_work
• Sum(hours*pay) where date is "THIS MONTH" and employee_id = e.id from nontaxed_work

I am not sure how to join these together properly. I don’t want to see any of the employees that have not done either kind of work for the month, only those who have. I’m using mysql and will put the data in a table with php

If anyone could tell me how to do the “THIS MONTH” part that would be cool too. Just being lazy on that part, but figured while I was here…

Thanks for the help!

Answer 1

You could use correlated subqueries:

select  concat(first_name, ' ', last_name)
,       (
        select  sum(hours*pay)
        from    taxed_work tw
        where   tw.employee_id = e.id
                and year(tw.date) = year(now())
                and month(tw.date) = month(now())
        )
,       (
        select  sum(hours*pay)
        from    nontaxed_work ntw
        where   ntw.employee_id = e.id
                and year(ntw.date) = year(now())
                and month(ntw.date) = month(now())
        )
from    employees e