如何加入两个sql子查询

Question

I have 2 tables
the 1st one name is (employee) has 3 columns (emp_id, first_name, last_name)
the 2nd table name is (works_with) has also 3 columns (emp_id, client_id, total_sales)
in (works_with) table the same emp_id can be related to different client_id

I need to extract the (first_name) and (last_name) form (employee) table and their (total_sales) of more than 30000 from (work_with) table

I used this code to give me the (emp_id)* with the (total_sales) of more than 30000

SELECT SUM(works_with.total_sales), works_with.emp_id
FROM works_with
WHERE works_with.emp_id IN (SELECT works_with.emp_id
                            FROM works_with 
                            WHERE works_with.total_sales > 30000) 
GROUP BY works_with.emp_id;

and I used this code to give me the (first_name) and (last_name) of those (emp_id)*

SELECT employee.first_name, employee.last_name
FROM employee
WHERE employee.emp_id IN (SELECT works_with.emp_id
                          FROM works_with
                          WHERE works_with.total_sales > 30000);

is there a way to join the 2 codes or any other way to have the result that I want

Thank you

Answer 1

Are you just looking for a JOIN ?

SELECT e.first_name, e.last_name, SUM(ww.total_sales)
FROM works_with ww JOIN
     employee e
     ON ew.emp_id = ww.emp_id
WHERE ww.emp_id IN (SELECT ww2.emp_id
                    FROM works_with  ww2
                    WHERE ww.total_sales > 30000
                   ) 
GROUP BY e.emp_id, e.first_name, e.last_name;

The subquery is not needed. It is implementing this logic:

SELECT e.first_name, e.last_name, SUM(ww.total_sales)
FROM works_with ww JOIN
     employee e
     ON ew.emp_id = ww.emp_id
GROUP BY e.emp_id, e.first_name, e.last_name
HAVING MAX(ww.total_sales) > 30000;

However, I suspect that you want:

SELECT e.first_name, e.last_name, SUM(ww.total_sales)
FROM works_with ww JOIN
     employee e
     ON ew.emp_id = ww.emp_id
GROUP BY e.emp_id, e.first_name, e.last_name
HAVING SUM(ww.total_sales) > 30000;

Answer 2

Contributing here since I noticed an error in the other answer. See here for how different types of JOINs work: (Link) .

SELECT 
    Employee.First_Name, 
    Employee.Last_Name, 
    SUM(WW.Total_Sales)
FROM 
    Works_With AS WW
        INNER JOIN Employee AS Employee
            ON Employee.EMP_ID = WW.EMP_ID
GROUP BY 
    Employee.EMP_ID, 
    Employee.First_Name, 
    Employee.Last_Name
HAVING 
    SUM(WW.Total_Sales) > 30000;