如何从一个表中获取所有列，而从另一张表中仅获取具有ID的一列？ -MySQL

Question

I have table employee which contains about 9 columns . ' id,name,etc..'

and I have another table 'onCall' contain 3 columns 'employee_id,department_id and rank '

what I want is to retrieve the employee data who is registered as OnCall employee on this department

I try this to get the employee data :

Select * from employee where id in (SELECT employee_id FROM onCall where department_id = 3)

But like this I can't know what is the rank of the onCall employee , is he registered as primary or backup ,how can I merge rank column from onCall table but only for the selected employee by the id

I tried to join them but I get syntax error

any way to solve this ?

Answer 1

This may help you and use the required columns with table alias name

Select e.*, o.* from employee e 
LEFT JOIN onCall o ON o.employee_id = e.id
    AND o.department_id = 3

Answer 2

This calls for an inner join

select EMP.*, OC.*
from EMPLOYEE EMP
inner join ONCALL OC
on OC.EMPLOYEE_ID = EMP.ID
where OC.DEPARTMENT = 3