How to create a widget with a populated dropdown?

Question

(added the code; I thought I had it in here) I am trying to build a widget that has a dropdown.

   public function form($instance) {
       global $wpdb;
       global $event;
       global $events;
       $events = $wpdb->get_results ( "SELECT id, event FROM $wpdb->mo_Event" );         

       name;?>
    <label for="<?php echo $this->get_field_id('event'); ?>">'Select an Event'</label>
      <select class="dropdown" id="mydropdown" name="mydropdown" title="My Dropdown">
      <?php
        foreach ($events as $value) {
            echo '<option value="' . unserialize($value) . '">' . unserialize($value) . '</option>';
      } // for each
    ?>          
  </select>
<?php    
} //  function form   

I have no idea what is going in here. My query is : SELECT id, event FROM $wpdb->mo_Event, but he debug log shows : The debug.log shows: SELECT event FROM [30-Apr-2020 15:35:04 UTC] WordPress database error You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 1 for query SELECT event FROM made by wp_list_widgets, wp_widget_control, call_user_func_array, WP_Widget->form_callback, gdd_Events_widget->form

The plugin Activates and widget has a small, empty dropdown.

Can someone help me get this right so that I can make a proper widget?

Thanks...Dan'l

Answer 1

I finally got the widget built. I hope this will help another newbie.

<?php

/*
 *  Plugin Name: Events Widget
  Description: This widget allows the user to select an Event name.
  Version: 0.5
  Author: Dan Statham
 */


function gdd_Events_load_widgets() {
    write_log('gdd _Events_load_widgets');
}// gdd_Events_load_widgets

// Register the widget
function my_register_events_widget() {
    register_widget( 'gdd_Events_load_widgets' );
} //  echo('registerd');

function submit(){
   if(isset($_POST['submit'])){
      $selected_val = $_POST['Color'];  // Storing Selected Value In Variable
     echo "You have selected :" .$selected_val;  // Displaying Selected Value
}

}
add_action( 'widgets_init', 'my_register_events_widget' );  


// The widget class
class gdd_Events_load_widgets extends WP_Widget {
    function gdd_Events_Widget() {
        /* Widget settings. */
        $widget_ops = array( 'classname' => 'event', 
                    'description' => __('Allow the user to select an Event name.', 'event') );

        /* Widget control settings. */
        $control_ops = array( 'width' => 200, 'height' => 150, 'id_base' => 'gdd_Events_Widget' );

        /* Create the widget. */
        $this->WP_Widget( 'Event', __('Event Name', 'event'), $widget_ops, $control_ops );
    } // function gdd_Events_Widget
    // Main constructor
    function __construct() {
        parent::__construct(                
                // base ID of the widget
                'gdd_Events_Widget',
                // name of the widget
                __('Event Names', 'events'),
                // widget options
                array(
                    'description' => __('Select the Event name.',
                            'events')
               )
        ); //parent __construct()
    }//function __construct()

    public function update($new_instance, $old_instance) {
        $instance = $old_instance;
        $instance['eventsdropdown'] = strip_tags($new_instance['eventsdropdown']);
        return $instance;
    }
// function update

    public function widget($args, $instance) {
        // kick things off
        extract($args);
    }//function widget
    // run a query if on a page
    public function gdd_Events_Register_Widget() {
        register_widget('gdd_Events_Widget');
    }


public function form( $instance ) {

    if ( isset( $instance[ 'eventsdropdown' ] ) )
    $selectedvalue = $instance[ 'eventsdropdown' ];
    else
    $selectedvalue = __( '', 'text-domain' );

    global $event;
    global $events;       
    global $wpdb;  
    global $depth;

     $events = $wpdb->get_results("SELECT id, event, description FROM mo_events order by event",ARRAY_A);
     ?>

     <label for="<?php echo $this->get_field_id('event'); ?>">Select an Event</label> <br>
     <select class="dropdown" id="eventsdropdown" name="eventsdropdown" title="Events Dropdown">

    <?php  
     foreach ($events as $event) {?>
             <option value=" <?php echo $event['id'] ?>"><?php echo $event['event']; ?></option> 
    <?php
    }   ?>
    </select> 
    <br><br> 

    <label for="newevent">Enter a new event name:</label><br>
    <input type="text"id="newevent" newevent="newevent" width="100"</input><br>
    <label for="newevent">Enter a short description:</label><br>
    <input type="textarea" id="neweventdescr" newevent="neweventdescr" width ="400" height="200"</input><br><br> <?
  } // function form  
} //class