title: Codeigniter and oracle undefined constant: OCI_COMMIT_ON_SUCCESS
body: <p>I develloping a web-based application with codeigniter and when I try to connect to my oracle entreprise 9g database the framework send me this error:</p>
  
  <pre><code>    A PHP Error was encountered
  
  Severity: Notice
  
  Message: Use of undefined constant OCI_COMMIT_ON_SUCCESS - assumed 'OCI_COMMIT_ON_SUCCESS'
  
  Filename: database/DB.php
  
  Line Number: 142
  </code></pre>
  
  <p>I tried different method to connect (classic, <a href="http://codeigniter.com/wiki/Oracle%3aKnown_Issues/" rel="noreferrer">oracle specific</a>).
  There is my config/database.php file.</p>
  
  <pre><code>$active_group = 'default';
  $active_record = TRUE;
  
  $db['default']['hostname'] = '(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=*xxx.xxx.xxx.xxx*)(PORT=1521))(CONNECT_DATA=(SID=*DB_NAME*)))';
  $db['default']['username'] = '*username*';
  $db['default']['password'] = '*password*';
  $db['default']['database'] = '';
  $db['default']['dbdriver'] = 'oci8';
  $db['default']['dbprefix'] = '';
  $db['default']['pconnect'] = TRUE;
  $db['default']['db_debug'] = TRUE;
  $db['default']['cache_on'] = FALSE;
  $db['default']['cachedir'] = '';
  $db['default']['char_set'] = 'utf8';
  $db['default']['dbcollat'] = 'utf8_general_ci';
  $db['default']['swap_pre'] = '';
  $db['default']['autoinit'] = TRUE;
  $db['default']['stricton'] = FALSE;
  </code></pre>
  
  <p>I think it's not a connection error, can you help me?</p>