Need help finding only Employees and Sales Persons in SQL
<p>I am trying to run an SQL query which would fetch me all people who are
1. Only employees, 
2. Employees and a sales person and 
3. Only sales persons. 
I am working on the Oracle E-Business Suite. So far, my query returns only those people who are employees only and those people who are employees and also a sales person. Here is what I've managed so far:</p>

<pre><code>select distinct PAF.LAST_NAME,
  PAF.START_DATE "HIRE_DATE",
  PAF.EMPLOYEE_NUMBER,
  PPT.SYSTEM_PERSON_TYPE "PERSON_TYPE",
  JRS.SALES_CREDIT_TYPE_ID,
  JRS.SALESREP_NUMBER
from PER_ALL_PEOPLE_F PAF,
  PER_PERSON_TYPES PPT,
  PER_PERSON_TYPE_USAGES_F PPTU,
  JTF_RS_DEFRESOURCES_VL JRDV,
  JTF_RS_SALESREPS JRS
where PAF.PERSON_ID          = PPTU.PERSON_ID                
and PPTU.PERSON_TYPE_ID      = PPT.PERSON_TYPE_ID             
and PPT.SYSTEM_PERSON_TYPE  in ('EMP','OTHER')
and JRDV.category           in ('EMPLOYEE','OTHER')
and (JRS.SALESREP_NUMBER(+) = PAF.EMPLOYEE_NUMBER)
and sysdate between PAF.EFFECTIVE_START_DATE and PAF.EFFECTIVE_END_DATE;
</code></pre>

<p><a href="http://i.stack.imgur.com/2hEJm.jpg" rel="nofollow">This is what I want to achieve</a></p>

<p>I have to include those people who are ONLY salespersons. Basically, there should be some rows which have no Employee_Number but only SALESREP_NUMBER. What am I doing wrong?</p>