how can I select the other departments from this query <p>So I have the following query</p> <pre><code>SELECT deptno, COUNT(deptno) number_of_jobs FROM emp WHERE job = 'SALESMAN' GROUP BY deptno ORDER BY number_of_jobs ASC; </code></pre> <p>What this does is to return me just department 30, while I want departments 10 and 20 aswell.</p> <p>Like this</p> <pre><code>deptno number_of_jobs 10 (here it can be null or 0 doesn't really matter) 20 (same like dept 10) 30 4 </code></pre> <p>I know this is fairly easy and I believe it's done using a join condition, but I just can't get my head around it.</p> <p>Thanks guys!</p>