setting table1.column = table2.column possible restriction on new column

Question

I have a datatable being populated bt one table, but also use a 2nd table to run a conditional Sum(case when...)

The initial query which works fine is:

$sql = "SELECT `add_job`.*,
                                SUM(addincome) AS income,
                                SUM(addpayment) AS cost,
                                SUM(`add_job`.`addincome` - `add_job`.`addpayment`) / SUM(`add_job`.`addpayment`)*100 AS markup,
                                SUM((add_job.addincome * 1.2) - add_job.addincome) AS vat_in
                                FROM`add_job`";
    $query = mysqli_query($conn, $sql);

I have another query which works fine on its own but when I try to join it into the above, it breaks the table and shows no data

"SELECT `driver`.*, 
    SUM(CASE WHEN `driver`.vatregistered= 'Y' then `add_job`.addpayment Else 0 end) * 0.2 as vat_pay 
    FROM `driver` 
    LEFT JOIN `add_job` ON `add_job`.adddriver = `driver`.drivercompany";

I run these queries through PHP and populate the datatables with the outcomes.

I would very much appreciate of someone could help me join the two queries

Answer 1

Incase anyone comes up against this sort of thing going forward... I grouped together as so:

$sql = "SELECT *, FROM (SELECT `add_job`.*,
        SUM(addincome) AS income,
        SUM(addpayment) AS cost,
        SUM(`add_job`.`addincome` - `add_job`.`addpayment`) / SUM(`add_job`.`addpayment`)*100 AS markup,
        SUM((add_job.addincome * 1.2) - add_job.addincome) AS vat_in
        FROM `add_job`) q1 
            join 
                (SELECT `driver`.*, 
                SUM(CASE WHEN `driver`.vatregistered= 'Y' then `add_job`.addpayment Else 0 end) * 0.2 as vat_pay 
                FROM `driver` 
                LEFT JOIN `add_job` ON `add_job`.adddriver = `driver`.drivercompany) q2 on 0=0";
$query = mysqli_query($conn, $sql);

Where q1 in the answer refers to Query 1 in question and q2 to Query 2.