Exclude current post from loop - php

Question

I want to add a Wordpress loop for a specific category in a post template that exculdes the current post.
I was suggested to use:
<?php
global $wp_query;
$cat_ID = get_the_category($post->ID);
$cat_ID = $cat_ID[0]->cat_ID;
$this_post = $post->ID;
query_posts(array('cat' => $cat_ID, 'post__not_in' => array($this_post), 'posts_per_page' => 14, 'orderby' => 'rand'));
?>
But I'm having trouble getting it to work.
My loops currently looks like this.
<div class="video">
<?php
$catquery = new WP_Query( 'category_name=video&posts_per_page=4' );
while($catquery->have_posts()) : $catquery->the_post();
?>
<div>
<a href="<?php the_permalink(); ?>">
<?php the_post_thumbnail(); ?>
<h2><?php the_title(); ?></h2>
</a>
</div>
<?php endwhile; ?>
<p class="more">M<br>O<br>R<br>E</p>
</div>

Answer 1

Try this code.
$postid = get_the_ID();
$args=array(
'post__not_in'=> array($postid),
'post_type' => 'post',
'category_name'=>'video',
'post_status' => 'publish',
'posts_per_page' => 4
);
<div class="video">
<?php
$catquery = new WP_Query( $args );
while($catquery->have_posts()) : $catquery->the_post();
?>
<div>
<a href="<?php the_permalink(); ?>">
<?php the_post_thumbnail(); ?>
<h2><?php the_title(); ?></h2>
</a>
</div>
<?php endwhile; ?>
<p class="more">M<br>O<br>R<br>E</p>
</div>

Answer 2

Use
'post__not_in' => array($post->ID)

Answer 3

The two code blocks are using two different techniques for a Wordpress custom loop... the first modifies the global query, and the second creates a new custom query. I've outlined both below with your loop template.
Example with suggested code, global query:
Loop through the global $wp_query object in the loop code:
<div class="video">
<?php
global $wp_query;
$cat_ID = get_the_category($post->ID);
$cat_ID = $cat_ID[0]->cat_ID;
$this_post = $post->ID;
query_posts(array('cat' => $cat_ID, 'post__not_in' => array($this_post), 'posts_per_page' => 14, 'orderby' => 'rand'));
?>
<!-- use the global loop here -->
<?php while ( have_posts() ) : the_post(); ?>
<div>
<a href="<?php the_permalink(); ?>">
<?php the_post_thumbnail(); ?>
<h2><?php the_title(); ?></h2>
</a>
</div>
<?php endwhile; ?>
<p class="more">M<br>O<br>R<br>E</p
</div>
Example with original code, custom query:
Loop through the custom query, adding 'post__not_in':
<div class="video">
<?php
$catquery = new WP_Query( 'category_name=video&posts_per_page=4&post__not_in=' . $post->ID );
while($catquery->have_posts()) : $catquery->the_post();
?>
<div>
<a href="<?php the_permalink(); ?>">
<?php the_post_thumbnail(); ?>
<h2><?php the_title(); ?></h2>
</a>
</div>
<?php endwhile; ?>
<p class="more">M<br>O<br>R<br>E</p>
</div>
Sorry if my original answer was unclear, I initially thought you were combining the two code blocks.