How do I exclude the current post from the upcoming post query

Question

Summary: I have a page template with 3 queries.

1. Current Exhibition
2. Upcoming Exhibition
3. Past Exhibition

The dates are custom fields. The problem I'm having is, how do I dynamically exclude the current post date from the upcoming exhibition query. After some digging around, I found I could use 'post__not_in'. Some examples below:

Example 1

$args  = array(
    'post_type'      => 'post',
    'posts_per_page' => 1,
    'cat'            => 14,
    'post__not_in'   => array( 71, 1 ),
    'orderby'        => 'date',
    'order'          => 'ASC',
    'post_status'    => 'publish',
);
$the_query = new WP_Query( $args )

;

Example 2

$args = array(
    'numberposts' => 5,
    'offset' => 0,
    'category' => 7,
    'post__not_in' => array( $post->ID )
);
$myposts2 = get_posts($args);

What is the proper usage for post not in to work with custom field dates? My code below -- Query Two "Upcoming Exhibitions"

<?php
/**
 * The template for displaying archive pages.
 * 
 * Template Name: Exhibition 
 *
 * Learn more: http://codex.wordpress.org/Template_Hierarchy
 *
 * @package boxpress
 */

get_header(); ?>

  <?php // require_once('template-parts/banners/banner--artist.php'); ?>

  <!-- // Query One -- pulls in current event   -->

  <?php 
   $exhibition_start_date = get_field('exhibition_start_date');
   $exhibition_end_date = get_field('exhibition_end_date');
   ?>

  <?php
  wp_reset_query();
  $exhibition_current_query = array(
    'post_type' => 'exhibition',
    'meta_key' => 'exhibition_start_date', // name of custom field
    'orderby' => 'meta_value',
    "order" => 'ASC',
    "posts_per_page" => 1,
    'meta_query' => array(
          array(
            'key' => 'exhibition_start_date',
            'value' => date('Y-m-d'),
            'compare' => '>=',
            'type' => 'DATE'
          )
        ),
    );
  $exhibition_current_loop = new WP_Query( $exhibition_current_query );
  ?>


<section class="section">
  <div class="wrap">
    <h2>Current Exhibitions</h2>
    <?php if ( $exhibition_current_loop->have_posts() ) : ?>
    <div class="l-grid l-grid--four-col">
      <?php while ( $exhibition_current_loop->have_posts() ) : $exhibition_current_loop->the_post(); ?>


       <div class="l-grid-item">
        <div style="display: flex;" class="date">
          <span class="start"><?php the_field('exhibition_start_date') ?></span> -
          <span class="end"><?php the_field('exhibition_end_date') ?></span>
        </div>
        <h4><?php the_title() ?></h4>
         <?php // get_template_part( 'template-parts/content/content-staff' ); ?>
       </div>

      <?php endwhile; ?>  
    </div>
    <?php endif; ?>
    <?php wp_reset_query(); ?>
    

    <!-- // Query Two -- pulls in upcoming event  -->

    <?php
    wp_reset_query();
    $exhibition_upcoming_query = array(
      'post_type' => 'exhibition',
      'orderby' => 'meta_value',
      'order' => 'ASC',
      'posts_per_page' => 3,
      'meta_query' => array(
            array(
              'key' => 'exhibition_start_date',
              'value' => date('Y-m-d'),
              'compare' => '>',
              'type' => 'DATE',
            )
          ),
      );
    $myposts2 = get_posts($exhibition_upcoming_query);
    $exhibition_upcoming_loop = new WP_Query( $exhibition_upcoming_query );
    ?>

    <h2>Upcoming Exhibitions</h2>

    <?php if ( $exhibition_upcoming_loop->have_posts() ) : ?>
    <div class="l-grid l-grid--four-col">
      <?php while ( $exhibition_upcoming_loop->have_posts() ) : $exhibition_upcoming_loop->the_post(); ?>


       <div class="l-grid-item">
      <div style="display: flex;" class="date">
        <span class="start"><?php the_field('exhibition_start_date') ?></span> -
        <span class="end"><?php the_field('exhibition_end_date') ?></span>
      </div>
      <h4><?php the_title() ?></h4>
         <?php // get_template_part( 'template-parts/content/content-staff' ); ?>
       </div>

      <?php endwhile; ?>  
    </div>
    <?php endif; ?>

    <!-- // Query Three -- pulls in past event  -->

    <?php
    wp_reset_query();
    $exhibition_past_query = array(
      'post_type' => 'exhibition',
      'orderby' => 'meta_value',
      "order" => 'DESC',
      "posts_per_page" => 8,
      'meta_query' => array(
            array(
              'key' => 'exhibition_start_date',
              'value' => date('Y-m-d'),
              'compare' => '<',
              'type' => 'DATE'
            )
          ),
      );
    $exhibition_past_loop = new WP_Query( $exhibition_past_query );
    ?>

    <h2>Past Exhibitions</h2>

    <?php if ( $exhibition_past_loop->have_posts() ) : ?>
    <div class="l-grid l-grid--four-col">
      <?php while ( $exhibition_past_loop->have_posts() ) : $exhibition_past_loop->the_post(); ?>


       <div class="l-grid-item">
        <div style="display: flex;" class="date">
          <span class="start"><?php the_field('exhibition_start_date') ?></span> -
          <span class="end"><?php the_field('exhibition_end_date') ?></span>
        </div>
        <h4><?php the_title() ?></h4>
         <?php // get_template_part( 'template-parts/content/content-staff' ); ?>
       </div>

      <?php endwhile; ?>  
    </div>
    <?php endif; ?>


  </div>
</section>

<?php get_footer(); ?>

Answer 1

I think you are asking how to exclude the current exhibition from your upcoming exhibitions query.

If that is the case, simply insert the ID of the current exhibition into the query using 'post__not_in':

$exhibition_upcoming_query = array(
  'post_type' => 'exhibition',
  'orderby' => 'meta_value',
  'order' => 'ASC',
  'posts_per_page' => 3,
  'post__not_in' => array( $exhibition_current_loop->posts[0]->ID ),
  'meta_query' => array(
        array(
          'key' => 'exhibition_start_date',
          'value' => date('Y-m-d'),
          'compare' => '>',
          'type' => 'DATE',
        )
      ),
  );

Hit me up if I am misunderstanding what you are after.