使用子查询选择多行

Question

The question asks "Display the names of all employees whose job title is the same as anyone in the sales dept" but

SELECT name, job 
FROM Employer WHERE job=(SELECT job FROM employer WHERE dept = sales);

does not work because the sub-query returns more than one value. How do I work around this?

Answer 1

Try to use in

SELECT name, job 
    FROM Employer 
    WHERE job in (SELECT job FROM employer WHERE dept = sales);

Answer 2

@Parado has the simplest solution. Keep in mind, however, that the in keyword is really just a join . For example, your query is the same as:

SELECT e1.name, e1.job
FROM Employer e1
    JOIN Employer e2 on e1.job = e2.job
WHERE e2.dept = 'sales'