This is my current query:
query_posts(array_merge(array('tag' => $pagetag,'meta_key'=>priority,'orderby' =>meta_value, 'order' =>'ASC','paged' => get_query_var('paged'))));
My problem is that the query shows me only the post that has values for my 'meta_key' meaning that 'priority' is not NULL. How can I improve this query so that it will still orderby my meta_key but will show all the posts that aren't NULL as well?
Thanks in advance!
The problem is that WordPress adds an INNER JOIN to the wp_postmeta table as soon as you mention meta_key in your conditions. One way around the problem is to add a filter on the order by clause, something like this:
function so_orderby_priority($original_orderby_statement) {
global $wpdb;
return "(SELECT $wpdb->postmeta.meta_value
FROM $wpdb->postmeta
WHERE $wpdb->posts.ID = $wpdb->postmeta.post_id
AND $wpdb->postmeta.meta_key = 'priority') ASC";
}
add_filter('posts_orderby', 'so_orderby_priority');
query_posts(
array(
'tag' => $pagetag,
'paged' => get_query_var('paged')
)
);
remove_filter('posts_orderby', 'so_orderby_priority');
Note MySQL sorts NULLs first - if you want them sorted last, try something like this (assuming all your priorities come before ZZZZZ alphabetically):
function so_orderby_priority($original_orderby_statement) {
global $wpdb;
return "IFNULL(
(SELECT $wpdb->postmeta.meta_value
FROM $wpdb->postmeta
WHERE $wpdb->posts.ID = $wpdb->postmeta.post_id
AND $wpdb->postmeta.meta_key = 'priority'),
'ZZZZZ') ASC";
}
Edit
Here's a bit more explanation, which assumes you understand SQL at least a bit.
Your original query_posts resulted in the following query running against the database:
SELECT wp_posts.*
FROM wp_posts
INNER JOIN wp_term_relationships ON ( wp_posts.id = wp_term_relationships.object_id )
INNER JOIN wp_postmeta ON ( wp_posts.id = wp_postmeta.post_id )
WHERE 1 = 1
AND ( wp_term_relationships.term_taxonomy_id IN ( 3 ) )
AND wp_posts.post_type = 'post'
AND ( wp_posts.post_status = 'publish'
OR wp_posts.post_status = 'private' )
AND ( wp_postmeta.meta_key = 'priority' )
GROUP BY wp_posts.id
ORDER BY wp_postmeta.meta_value ASC
LIMIT 0, 10;
That INNER JOIN wp_postmeta is what removed any posts without a priority from your results.
Removing the meta_* related conditions from your query_posts:
query_posts(
array(
'tag' => $pagetag,
'paged' => get_query_var('paged')
)
);
solved that problem, but the sort order is still wrong. The new SQL is
SELECT wp_posts.*
FROM wp_posts
INNER JOIN wp_term_relationships ON ( wp_posts.id = wp_term_relationships.object_id )
WHERE 1 = 1
AND ( wp_term_relationships.term_taxonomy_id IN ( 3 ) )
AND wp_posts.post_type = 'post'
AND ( wp_posts.post_status = 'publish'
OR wp_posts.post_status = 'private' )
GROUP BY wp_posts.id
ORDER BY wp_posts.post_date DESC
LIMIT 0, 10;
The posts_orderby filter allows us to change the ORDER BY clause: wp_posts.post_date DESC gets replaced by what the filter returns. The final SQL becomes:
SELECT wp_posts.*
FROM wp_posts
INNER JOIN wp_term_relationships ON ( wp_posts.id = wp_term_relationships.object_id )
WHERE 1 = 1
AND ( wp_term_relationships.term_taxonomy_id IN ( 3 ) )
AND wp_posts.post_type = 'post'
AND ( wp_posts.post_status = 'publish'
OR wp_posts.post_status = 'private' )
GROUP BY wp_posts.id
ORDER BY (SELECT wp_postmeta.meta_value
FROM wp_postmeta
WHERE wp_posts.id = wp_postmeta.post_id
AND wp_postmeta.meta_key = 'priority') ASC
LIMIT 0, 10
which does what you're after.
I needed to perform a similar task on the users.php page for a custom column I added and used the following code that I modified from Hobo
add_action('pre_user_query', 'qd_users_column_orderby');
function qd_users_column_orderby($userquery){
if('my_last_login'==$userquery->query_vars['orderby']) { //check if my cusomt meta_key is the column being sorted
global $wpdb;
$userquery->query_orderby = " ORDER BY(SELECT $wpdb->usermeta.meta_value
FROM $wpdb->usermeta
WHERE $wpdb->users.ID = $wpdb->usermeta.user_id
AND $wpdb->usermeta.meta_key = 'my_last_login') ".($userquery->query_vars["order"] == "ASC" ? "asc " : "desc ")." , wp_users.user_login ".($userquery->query_vars["order"] == "ASC" ? "asc " : "desc ");
}
}
Hopefully this helps somebody in need of this information.
In an effort of being throughout, the remainder of the necessary code to complete my individual task is below.
add_filter('manage_users_columns', 'qd_add_user_login_column');
function qd_add_user_login_column($columns) {
$columns['my_last_login'] = 'Last Logged In';
return $columns;
}
add_action('manage_users_custom_column', 'qd_show_user_login_column_content', 10, 3);
function qd_show_user_login_column_content($value, $column_name, $user_id) {
$user = get_userdata( $user_id );
if ( 'my_last_login' == $column_name ){
$lastLogin = get_the_author_meta('my_last_login', $user_id);
if(!$lastLogin){
return "Never";
}else{
date_default_timezone_set(get_option('timezone_string'));
return date('m/d/y g:ia', $lastLogin);
}
}
return $value;
}
add_filter( 'manage_users_sortable_columns', 'qd_users_table_sorting' );
function qd_users_table_sorting( $columns ) {
$columns['my_last_login'] = 'my_last_login';
return $columns;
}
The Issue: Sorting by a custom field without excluding posts that don't have a value set for that custom field.
Hobo's answer explains this well. Here I'm just going to offer a simpler alternative that ended up being easier in my case (Please note this won't work correctly if pagination is needed).
I decided to do the sorting in PHP after the query is made. The nice part is that I have better control over where the posts with null values end up (I wanted them to show up last).
$query = new WP_Query($args);
//sort by rank
function customSort($a, $b)
{
$a = get_field("sort_ranking", $a);
$b = get_field("sort_ranking", $b);
//handle nulls
$a = is_numeric($a) ? $a : 9999;
$b = is_numeric($b) ? $b : 9999;
if ($a == $b) return 0;
return ($a < $b) ? -1 : 1;
}
usort($query->posts, "customSort");
Here I have a numeric custom field called sort_ranking and I'm using it to sort ASC. Posts with a null value for this field are assigned 9999 so that they end up at the end. (Note: I'm using ACF, hence the get_field function)
Hope this helps someone!
The easiest way to do this is to insert the custom field using save_post action, so every post published will have its own meta_key with a default value.
Use a MySQL query for add post_meta to all posts has not the meta. Thats it.
If you/anyone need code help on this, just reply :)
UPDATE
As Timusan asked, add this code in your functions.php file after changing the meta-key name :
add_action('save_post', 'sidati_post_views_metakey');
function sidati_post_views_metakey ($post_id){
/*
* $post_id = is the post ID
* 'sidati_post_views' => is your metakey name (sidati is prefix always nice to add your prefix)
* 0 => the inital value
* true => (bool) add true if you want this metakkey become unique
*/
add_post_meta($post_id, 'sidati_post_views', 0, true);
}
// THIS ACTION MUST RUN ONLY ONE TIME
add_action('init', 'sidati_allposts_must_have_this');
function sidati_allposts_must_have_this(){
/* Call the WordPress DataBase class */
global $wpdb;
/* This Query will get us all the posts and pages without "sidati_post_views" metakey. */
$ids = $wpdb->get_row("SELECT ID FROM wpdb->posts WHERE post_type IN ('post', 'page') AND post_status = 'publish' AND ID NOT IN (SELECT post_id FROM $wpdb->postmeta WHERE meta_key = 'sidati_post_views')");
/* After get all posts/pages, now you need to add the meta keys (this may take a few munites if you have many posts/pages)*/
foreach ($ids as $post_id) {
add_post_meta($post_id, 'sidati_post_views', 0, true);
}
}
