How to see if a post exists based on a meta value - php

Question

Is there any way to see if a post exists by a meta value?
For instance, lets say I want to see if another post has a unique meta value of "pictureID", and if so do something else.
Is there a way I could write that clause in php?
Thank you

Answer 1

if you dont know the post id then
you can use custom wordpress query to check post meta according to key like
global $wpdb;
$wpdb->get_results( "select * from $wpdb->postmeta where meta_key = 'pictureID' " );
And then you can get all results with post id and then get that post data.
Hope this helps ;)

Answer 2

You can use a standard WP_Query to return posts by meta_key using the meta_query argument and EXISTS compare type.
// query for all posts with the pictureID meta key set
$args = array(
'post_type' => 'post', // or your_custom_post_type
'meta_query' => array(
array(
'key' => 'pictureID',
'compare' => 'EXISTS',
),
),
}
// create a custom query
$my_query = new WP_Query( $args );
// loop over your query, creating a custom The Loop
if ( $my_query->have_posts() ): while ( $my_query->have_posts() ): $my_query->the_post();
// $post is now posts that have a pictureId meta value
endwhile; endif;
// reset $post
wp_reset_postdata();
If you want to quickly grab a random post_id that has this meta_key set you can go to the database directly (bypassing caching, etc).
global $wpdb;
// SQL statement to fetch the post_id using a meta_key and a published post
$sql = <<<SQL
SELECT post_id
FROM {$wpdb->postmeta} pm
JOIN {$wpdb->posts} p
ON p.ID = pm.post_id
AND post_status = 'publish'
AND post_type = 'post'
WHERE meta_key = 'pictureID'
AND meta_value != ''
AND post_id != %d
ORDER BY RAND()
LIMIT 1
SQL;
// exclude the current post by replacing %d with the current ID
$sql = $wpdb->prepare( $sql, $post->ID );
// use get_var() to return the post_id
$post_id = $wpdb->get_var( $sql );

Answer 3

first try to get meta value for post get_post_meta()
$postMetaValue=get_post_meta($postId,"meta_key",true);
if($postMetaValue=='pictureID')
{
//do as you want
}