title: duplicate entry error '0' when no zeros are there
body: <p>I have written the syntax: </p>
  
  <pre><code>CREATE TABLE ARTICLES(
      PMID INT NOT NULL, 
      PUBLICATION_TITLE CHAR(35), 
      ARTICLE_TITLE VARCHAR(60), 
      TYPE CHAR(15), 
      ABSTRACT TEXT,  
      ISSUE INT, 
      DAY INT, 
      MONTH CHAR(14), 
      YEAR INT, 
      START_PAGE INT, 
      END_PAGE INT, 
      PRIMARY KEY (PMID)
  );  
  </code></pre>
  
  <p>No errors occur here.</p>
  
  <p>Then I tried to import an excel file using: </p>
  
  <pre><code>LOAD DATA INFILE 'DATABASE_PROJECT/PUBMED_DATA.XLS' INTO TABLE ARTICLES;  
  </code></pre>
  
  <p>but it keeps giving me an error that says duplicate entry '0' for key primary.  None of the entries are a single digit, let alone '0'.  I don't know why this is happening.  Please help! </p>