title: Fixed Error ORA-00918
body: <p>I am trying to create TFIDF table. Below is my code:</p>
  
  <pre><code>CREATE TABLE TF_IDF2 (FILEID, WORD, TFIDF)AS
  select TF.FILEID, TF.WORD, (TF.FREQ*B.IDF) AS TFIDF
  from TF JOIN IDF B
  ON TF.WORD=B.WORD;
  </code></pre>
  
  <p>Error message: </p>
  
  <blockquote>
    <p>SQL Error: ORA-00918: column ambiguously defined<br>
    00918. 00000 -  "column ambiguously defined"`. </p>
  </blockquote>
  
  <p>The error points to <code>WORD</code> in the last line of the query. Thanks.</p>