title: Possible to add multiple columns together and Alias in PL/SQL?
body: <p>I'm pretty green with SQL writing in general. What I am attempting to do is return a singular value from a SELECT query with multiple JOINS and WHERE Criteria.</p>
  
  <p>EX: The following returns the 3 values in question I am after:</p>
  
  <pre><code>SELECT TBL5.FIELD1, TBL5.FIELD2, TBL5.FIELD3 
  FROM TBL1 PA
  JOIN TBL2 PH ON PH.PAID = PA.PAID
  JOIN TBL3 CM ON CM.CMID = PA.ECMID
  JOIN TBL4 HD ON CM.SURID = HD.PHID
  JOIN TBL5 PD ON PD.PHID = HD.PHID
  WHERE PH.PSID = 1234
  AND PA.PAID = 10039528
  AND NVL(PA.ECMID,0) &gt; 0
  AND CM.CMTV = 'EECR'
  AND PD.MAID = 939252
  </code></pre>
  
  <p>What I want to do is return the value of all three columns TBL5.FIELD1, TBL5.FIELD2, TBL5.FIELD3 as (1) aliased field. With the record I am currently working at retrieving, the last 2 fields are null and the first field returns -32.47. But when I do the below, all I get returned is [null] instead of the expected (-32.47 + null + null) = (-32.47)?</p>
  
  <pre><code>SELECT (TBL5.FIELD1 + TBL5.FIELD2 + TBL5.FIELD3) AS TOTAL_REFUND
  FROM TBL1 PA
  JOIN TBL2 PH ON PH.PAID = PA.PAID
  JOIN TBL3 CM ON CM.CMID = PA.ECMID
  JOIN TBL4 HD ON CM.SURID = HD.PHID
  JOIN TBL5 PD ON PD.PHID = HD.PHID
  WHERE PH.PSID = 1234
  AND PA.PAID = 10039528
  AND NVL(PA.ECMID,0) &gt; 0
  AND CM.CMTV = 'EECR'
  AND PD.MAID = 939252
  </code></pre>