php - duplicate database name won't echo else condition -

this code create database in sql using input forms.

<?php   //connect sql $conn = new mysqli('127.0.0.1','root',''); if( $conn -> connect_error ){     echo $conn -> connect_error;     die('connection unsuccessful'); } echo 'connection sucessful';  ?>  <!-- ==================================================================== -->  <form action="" method="post">     <input type="text" name="db_name">     <input type="submit" value="create database"> </form>  <?php //create database if( isset( $_post["db_name"] ) && $dbname = $_post["db_name"] )     if( $conn -> query("create database if not exists " . $dbname ) === true )         echo 'database created sucessfully';     else          echo 'database ' . $dbname . ' exists. please try name'; //this line won't execute ?> 

in case of entering duplicate database name, want echo last line. don't know why not executing. help?

note: entering duplicate name won't create anything, page says "database created succesfully"

<?php //create database if( isset( $_post["db_name"] ) && $dbname = $_post["db_name"] )     if( $conn -> query("create database " . $dbname ) === true )          echo 'database created sucessfully';     else         echo 'database ' . $dbname . ' exists. please try name'; //this line won't execute ?> 

this should it, if you're using "if not exists" query successfully, if you're trying creat database name existing query fail, , not return true.