title: SQL 00918. 00000 - "column ambiguously defined"
body: <p>So I have the "column ambiguously defined" error in my sql oracle code and I can't figure out why I have the error. I know it means the code can't figure out which of two columns with the same name to use, so I need to use prefixes. But I have prefixes that are all correct. I looked at the other questions on this error message on the site, but can't figure it out.</p>
  
  <p>ORA-00918: kolumn inte entydigt definierad
  00918. 00000 -  "column ambiguously defined"
  *Cause:<br>
  *Action:
  Error at Line: 4 Column: 5</p>
  
  <pre><code>SELECT KUND.KNR, KUND.FNAMN, KUND.ENAMN
  FROM KUND, ORDERRAD, KUNDORDER, KUNDORDER, ARTIKEL, VARUGRUPP
  WHERE KUND.KNR = KUNDORDER.KNR
  AND KUNDORDER.ORDNR = ORDERRAD.ORDNR
  AND ORDERRAD.ARTNR = ARTIKEL.ARTNR
  AND ARTIKEL.VGNR = VARUGRUPP.VGNR
  AND VARUGRUPP.VGNAMN = 'skäggvård' OR VARUGRUPP.VGNAMN = 'bondgård';
  </code></pre>