如何将这两个查询结合起来，使结果在一个表中？

Question

First query:

SELECT integration_department_map.foreign_department_key AS 'Department Code', department.department_name AS 'Department Name'
FROM integration_department_map
JOIN department ON department.department_id = integration_department_map.department_id
WHERE integration_department_map.client_id = '10134';

Second query:

SELECT integration_department_map.foreign_department_key AS 'Department Code', location.location_name AS 'Location Name'
FROM integration_department_map
JOIN location ON location.location_id = integration_department_map.location_id
WHERE integration_department_map.client_id = '10134';

They both return the results needed separately, but I want to know if there is a way they could be written as one query?

Answer 1

As suggested by honeybadger in the comments . Just add a join to location table like:

SELECT 
    i.foreign_department_key AS `Department Code`, 
    d.department_name AS `Department Name`, 
    l.location_name AS `Location Name`
FROM integration_department_map i
JOIN department d
ON d.department_id = i.department_id
JOIN location l
ON l.location_id = i.location_id
WHERE i.client_id = 10134

And remove quotes around id if it's an int as it should be.

Answer 2

Perhaps what you are looking for is a LEFT JOIN and not a JOIN (inner join). How many lines in the original integration_department_map satisfy the WHERE clause, and are they the same lines?

maybe this will do the trick -

SELECT 
    i.id,
    i.foreign_department_key AS `Department Code`, 
    d.department_name AS `Department Name`, 
    l.location_name AS `Location Name`
FROM integration_department_map i
LEFT JOIN department d ON d.department_id = i.department_id
LEFT JOIN location l   ON l.location_id = i.location_id
WHERE i.client_id = 10134