title: Unable to connect to database in Amazon RDS from codeigniter 3
body: <p>I'm using these configs in my database.php file</p>
  
  <pre><code>$db['testing'] = array(
  'dsn'   =&gt; '',
  'hostname' =&gt; '----RDS HOST LINK------',
  'username' =&gt; 'XXXX',
  'password' =&gt; 'XXXX',
  'database' =&gt; 'test_db',
  'dbdriver' =&gt; 'mysqli',
  'dbprefix' =&gt; '',
  'pconnect' =&gt; FALSE,
  'db_debug' =&gt; (ENVIRONMENT !== 'production'),
  'cache_on' =&gt; FALSE,
  'cachedir' =&gt; '',
  'char_set' =&gt; 'utf8',
  'dbcollat' =&gt; 'utf8_general_ci',
  'swap_pre' =&gt; '',
  'encrypt' =&gt; FALSE,
  'compress' =&gt; FALSE,
  'stricton' =&gt; FALSE,
  'failover' =&gt; array(),
  'save_queries' =&gt; TRUE
  );
  </code></pre>
  
  <p>I'm getting a message that I'm not able to connect using the provided settings.</p>
  
  <p>However if i change the dbdriver to mysql, it states "Unable to select the specified db test_db".</p>
  
  <p>I tried setting up a persistant connection as well, using pconnect to true, still no luck.</p>
  
  <p>I'm able to connect to the rds using those credentials from mysql workbench and i created and dump the data into test_db as well. Dont know whats wrong with codeigniter. The MySQL ports are also open in RDS security group(obviously).</p>
  
  <p>Its the first time I'm facing such issue. What could have gone wrong?</p>