Only display upcoming events in Wordpress Widget - wordpress

Question

Through a shortcode I placed the following code which is intented to display a random upcoming event in the sidebar. At the moment it displays a random of ALL events. How would I change the code to only display events that are younger than the current date?
<?php
// Build a custom query to get posts from future dates.
$querystr = `
SELECT wposts.*
FROM $wpdb->posts wposts, $wpdb->postmeta wpostmeta
WHERE wposts.ID = wpostmeta.post_id
AND wpostmeta.meta_key = 'f21_event_startdate'
AND STR_TO_DATE(wpostmeta.meta_value,'j. M Y') >= CURDATE()
AND wposts.post_status = 'publish'
AND wposts.post_type = 'events'
ORDER BY STR_TO_DATE(wpostmeta.meta_value,'j. M Y') RAND
LIMIT 1
`;
$events = $wpdb->get_results($querystr, OBJECT);
if ($events):
global $post;
foreach ($events as $post):
setup_postdata($post); ?>
<?php the_field('f21_event_startdate'); ?>
<h2><a style="color:#1e73be;" href="<?php the_permalink() ?>"><?php the_title(); ?></h2>
<div style="margin-top:10px; margin-bottom: 10px;"><?php the_post_thumbnail('full'); ?></div></a>
<b><?php the_field('f21_event_sub_header'); ?></b>
<?php endforeach;
else : ?>
<li>Sorry, no events coming up.</li>
<?php endif; ?>

Answer 1

you can WP_Query(). check the code below.
$args = array(
'post_type' => 'events',
'posts_per_page' => -1,
'meta_key' => 'f21_event_startdate',
'meta_value' => date('Ymd'),
'meta_compare' => '>=',
'orderby' => 'rand',
'order' => 'ASC'
);
$upcoming_events = new WP_Query( $args );

Answer 2

Avoid the SQL query in WordPress for getting post-type data.
we have a function for that please use
$args = array(
'post_type' => 'tribe_events',
'post_status' => 'publish',
'posts_per_page' => 10,
'order' => 'ASC',
'orderby' => 'meta_value',
'meta_key' => '_EventStartDate',
'meta_type' => 'DATETIME',
'paged'=>$page,
'meta_query'=>array(
array(
'key' => '_EventStartDate',
'value' => date( 'Y-m-d H:i:s', current_time( 'timestamp' ) ),
'compare' => '>'
),),
'tax_query'=>array(array(
'taxonomy' => 'tribe_events_cat',
'field' => 'id',
'terms' =>$tribe_events_cat,
))
);
$events = new WP_Query($args);
Summary: if you are using custom fields in WordPress make sure your custom fields are stored as a post meta then you can easily filter that,
In the above code, we have a meta query where we can use key, value, and compare. thanks.