[WPDB CREATE TABLE]

wpdb-create-table.php

//
//                                                Write below codes in class file
//                                                _______________________________
<?php
/**
 * Here should be all table and column which will create table
 */
class InstallTable
{
    public static function event()
    {
        global $wpdb;
        $version = '1.0';
        $table_name       = $wpdb->prefix . 'event';
        $charset_collate  = $wpdb->get_charset_collate();

        $sql = "CREATE TABLE $table_name (
			id mediumint(11) NOT NULL AUTO_INCREMENT,
			created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
			modified_at DATETIME on update CURRENT_TIMESTAMP NOT NULL,
			name varchar(200) NOT NULL,
            		event_date DATE NOT NULL,
            		description varchar(200) NOT NULL,
			cell_color varchar(6) NOT NULL,
			PRIMARY KEY(id)
		) $charset_collate;";

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

        add_option('version', $version);
    }   
}
//
//                                        write below code in app.php
//

register_activation_hook(__FILE__, array('InstallTable', 'event'));