title: Sqlite3, OperationalError: unable to open database file
body: <p>Question: Why can't I open the database?</p>
  
  <hr>
  
  <p>Info: I'm working on a project using <code>sqlite3</code> database. I wrote a test program that runs and passes it the database:</p>
  
  <p><code>/tmp/cer/could.db</code></p>
  
  <p>The unit test program can make the <code>db</code> without any problem. But, when I actually use the program passing the same location to it, i got below error: </p>
  
  <blockquote>
    <p>OperationalError: unable to open database file</p>
  </blockquote>
  
  <p>I've tried doing it with:</p>
  
  <pre><code>1) an empty database.
  2) the database and the unit test left behind.
  3) no database at all.
  </code></pre>
  
  <p>In three cases, I got the above error. The most frustrating part has to be the fact that the <code>unittest</code> can do it just fine, but the actual program can't. </p>
  
  <p>Any clues as to what on earth is going on?</p>