Check if this is duplicate

Question

I want to check if the username already exists and throw an error message if exist, any tips how can I do it? I\'ve already tried to search but only found mys

Answer 1

 query("select * from user where name='$user_name");
     $rowCount=$getUniqueUsername->num_rows;

     if($rowCount) {          
          $insertQuery=$con->query("insert into table_name (field_name) Values('".$values."'));
     }
?>