Need help for creating custom table on wordpress

Question

I'm trying to learn how to create and use custom tables on wpdb for a plugin that I'm going to build. So far I've seen a bunch of tutorials and know how to create a table but I'm facing problems storing data and debugging my table.

so for my plugin I've created a main class where these functions are called

public function pre_install(){
    global $wpdb;
    global $pre_db_version;
    $pre_db_version='1.1';

    $table_name = $wpdb->prefix . 'prelauncher';

    $charset_collate = $wpdb->get_charset_collate();

    $sql = "CREATE TABLE $table_name (
    id mediumint(9) NOT NULL AUTO_INCREMENT,
    username tinytext NOT NULL,
    email varchar(255) NOT NULL,
    UNIQUE KEY id (id)
    ) $charset_collate;";

require_once( ABSPATH . 'wp-admin/includes/upgrade.php' );
        dbDelta( $sql );

add_option( 'pre_db_version', $pre_db_version );

}  

and then outside the class I called

register_activation_hook( __FILE__, array('main_class','pre_install'));

This should create a database table called wp_prelauncher with two columns, username and email which it does but it also creates two extra columns called my_title and show_title . Where are these two columns coming from I have no idea. I have searched my entire code but found nothing.

Also if anyone could point me in the direction where I could learn how to save user input in this table it will be a big help.

Answer 1

I guess, you can use the following function

public function pre_install()   {
global $wpdb;
require_once(ABSPATH . 'wp-admin/includes/upgrade.php');
$sql="
   CREATE TABLE IF NOT EXISTS `".$wpdb->prefix."prelauncher`
   (
      id mediumint(9) NOT NULL auto_increment,
      username tinytext NOT NULL,
      email varchar(255) NOT NULL,
      PRIMARY KEY  (`main_id`)
 );";
dbDelta($sql);
}

and than your activation hook.

register_activation_hook( __FILE__, array('main_class','pre_install'));

I dont think the $pre_db_versions - required for the this table creation.

I hope this will solve your problem.