Question

Here is the schema of the database I’m working with – [redacted]

I’m trying to come up with 2 different queries for 2 different result sets –

1. Sales representatives with the highest sales
2. Sales representatives with the highest sales grouped by managerId

I’ve had some luck with the 1st query; this is what I came up with:

SELECT
    SUM(`products`.`cost`) AS `Sale`
    , `employees`.`firstName`
FROM
    `d2dpro`.`sales_reps`
    , `d2dpro`.`products`
    INNER JOIN `d2dpro`.`employees` 
        ON (`sales_reps`.`employeeId` = `employees`.`employeeId`)
    INNER JOIN `d2dpro`.`sold_products` 
        ON (`products`.`productId` = `sold_products`.`productId`)
    INNER JOIN `d2dpro`.`sales` 
        ON (`sold_products`.`saleId` = `sales`.`saleId`) AND (`sales`.`salesCampId` = `sales_reps`.`saleCampId`)
GROUP BY `employees`.`firstName`;

With this query, I’m stuck with this error:
Error Code: 1054
Unknown column 'sales_reps.saleCampId' in 'on clause'

Any help with this query? And also for the 2nd one?

Answer 1

You are using one table (sales_reps) that is CROSS JOIN-ed with the INNER JOIN of the tables employees, sold_products and sales. To be able to reference sales_reps in that JOIN you should include it as inner join: (the FROM clause should look like this)

FROM `d2dpro`.`products`
    INNER JOIN `d2dpro`.`employees` 
        ON (`sales_reps`.`employeeId` = `employees`.`employeeId`)
    INNER JOIN `d2dpro`.`sold_products` 
        ON (`products`.`productId` = `sold_products`.`productId`)
    INNER JOIN `d2dpro`.`sales` 
        ON (`sold_products`.`saleId` = `sales`.`saleId`)
    INNER JOIN `d2dpro`.`sales_reps` 
        ON (`sales`.`salesCampId` = `sales_reps`.`saleCampId`)