obtenir toutes les valeurs pour une clé de champ personnalisé (cross-post)

Une approchepossible serait d'utiliser l'une desméthodes d'assistance de la classe WPDBpourfaire une requêtebasée sur desmétaplus raffinée. Lamiseen garde à l'utilisation de certaines de cesfonctions,cependant,est que vousne récupérezgénéralementpas un simpletableau de donnéeset que vous devezgénéralementfaire des référencesinutiles auxpropriétés d'objet,même si vousn'appelez qu'une seule colonne ou ligne.

Bien sûr,toutes lesfonctionsne sontpas lesmêmes,et unemention utile va à laméthode WPDB ,get_col qui renvoie un simpletableauplat du donnéesinterrogées,je fais cettemention spécifiquementparce que l'exemple suivantfera appel à cetteméthode.

WordPress - WPDB Sélection d'une colonne de données
$ wpdb->get_col ()

Voici unexemple defonction quiinterroge labase de donnéespourtoutes lespublications d'untype depublication,de l'état de lapublicationet d'uneméta clé spécifique (ou d'un champpersonnalisépour lesmoinstechniquementintéressés).

 function get_meta_values( $key = '', $type = 'post', $status = 'publish' ) {

    global $wpdb;

    if( empty( $key ) )
        return;

    $r = $wpdb->get_col( $wpdb->prepare( "
        SELECT pm.meta_value FROM {$wpdb->postmeta} pm
        LEFT JOIN {$wpdb->posts} p ON p.ID = pm.post_id
        WHERE pm.meta_key = %s 
        AND p.post_status = %s 
        AND p.post_type = %s
    ", $key, $status, $type ) );

    return $r;
}
 

Parexemple,si vous souhaitez savoir quelsmessages ont une cléméta de rating ,pour letype demessage films et que vous aimeriez stocker cesinformations dans une variable,unexemple d'untel appel serait ..

 $movie_ratings = get_meta_values( 'rating', 'movies' );
 

Si vousne vouliez rien d'autre que d'imprimer ces données à l'écran,lafonction d'implosion de PHPpeut rapidement scinder ce simpletableauen lignes de données.

 // Print the meta values seperate by a line break
echo implode( '<br />', get_meta_values( 'YOURKEY' ));
 

Vouspouvez également utiliser les données renvoyéespour déterminer lenombre d'articles contenant cesméta-valeursen effectuant une simpleboucle sur les données renvoyéeset en créant untableau des décomptes,parexemple.

 $movie_ratings = get_meta_values( 'rating', 'movies' );
if( !empty( $movie_ratings ) ) {
    $num_of_ratings = array();
    foreach( $movie_ratings as $meta_value )
        $num_of_ratings[$meta_value] = ( isset( $num_of_ratings[$meta_value] ) ) ? $num_of_ratings[$meta_value] + 1 : 1;
}

/*
Result:
Array(
    [5] => 10
    [9] => 2
)
// ie. there are 10 movie posts with a rating of 5 and 2 movie posts with a rating of 9.
*/
 

Cette logiquepeut être appliquée à différentstypes de donnéeset étenduepourfonctionner de différentesmanières. J'espère donc quemesexemples ont été utileset suffisamment simples à suivre.

One possible approach would be to use one of the helper methods in the WPDB class to do a more refined meta based query. The caveat to using some of these functions however, is that you don't usually get back a simple array of data and usually have to make needless references to object properties, even if you're only calling for one column or row.

Of course, not all functions are the one and the same, and a purposeful mention goes out to the WPDB method, get_col which returns a simple flat array of the data queried for, i make this mention specifically because the example following will call upon this method.

WordPress - WPDB Selecting a column of data
$wpdb->get_col()

Here's an example function which queries the database for all posts of a chosen post type, post status and with a specific meta key(or custom field to the less technically minded).

function get_meta_values( $key = '', $type = 'post', $status = 'publish' ) {

    global $wpdb;

    if( empty( $key ) )
        return;

    $r = $wpdb->get_col( $wpdb->prepare( "
        SELECT pm.meta_value FROM {$wpdb->postmeta} pm
        LEFT JOIN {$wpdb->posts} p ON p.ID = pm.post_id
        WHERE pm.meta_key = %s 
        AND p.post_status = %s 
        AND p.post_type = %s
    ", $key, $status, $type ) );

    return $r;
}

So for example, if you like to find out which posts have a meta key of rating, for the post type movies and you'd like to store that information inside a variable, an example of such a call would be..

$movie_ratings = get_meta_values( 'rating', 'movies' );

If you wanted to do nothing more than print that data to screen, PHP's implode function can quickly splice that simple array into lines of data.

// Print the meta values seperate by a line break
echo implode( '<br />', get_meta_values( 'YOURKEY' ));

You can also use the returned data to work out how many posts have these meta values by doing a simple loop over the returned data and building an array of the counts, for example.

$movie_ratings = get_meta_values( 'rating', 'movies' );
if( !empty( $movie_ratings ) ) {
    $num_of_ratings = array();
    foreach( $movie_ratings as $meta_value )
        $num_of_ratings[$meta_value] = ( isset( $num_of_ratings[$meta_value] ) ) ? $num_of_ratings[$meta_value] + 1 : 1;
}

/*
Result:
Array(
    [5] => 10
    [9] => 2
)
// ie. there are 10 movie posts with a rating of 5 and 2 movie posts with a rating of 9.
*/

This logic could be applied to various kinds of data, and extended to work any number of different ways. So i hope my examples have been helpful and simple enough to follow.

Je voudraisjuste ajouter unepetite chose au code de t31os ci-dessus.J'ai changé "SELECT"en "SELECT DISTINCT"pour éliminer lesentréesen double lorsquej'ai utilisé ce codemoi-même.

I'd just like to add one tiny thing to t31os's code above. I changed "SELECT" into "SELECT DISTINCT" to eliminate duplicate entries when I used this code myself.

Iln'estpasbon ounécessaire d'utiliser leglobal $ wpdb:

 // function to grab all possible meta values of the chosen meta key.
function get_meta_values( $meta_key,  $post_type = 'post' ) {

    $posts = get_posts(
        array(
            'post_type' => $post_type,
            'meta_key' => $meta_key,
            'posts_per_page' => -1,
        )
    );

    $meta_values = array();
    foreach( $posts as $post ) {
        $meta_values[] = get_post_meta( $post->ID, $meta_key, true );
    }

    return $meta_values;

}

$meta_values = get_meta_values( $meta_key, $post_type );
 

It is not good or needed to use the global $wpdb:

// function to grab all possible meta values of the chosen meta key.
function get_meta_values( $meta_key,  $post_type = 'post' ) {

    $posts = get_posts(
        array(
            'post_type' => $post_type,
            'meta_key' => $meta_key,
            'posts_per_page' => -1,
        )
    );

    $meta_values = array();
    foreach( $posts as $post ) {
        $meta_values[] = get_post_meta( $post->ID, $meta_key, true );
    }

    return $meta_values;

}

$meta_values = get_meta_values( $meta_key, $post_type );

lemoyen leplus rapide serait une requête SQLpersonnaliséeet jene suispas sûrmais vouspouvezessayer

 $wpdb->get_results("
  SELECT posts.* , COUNT(*) 'moodcount'
  FROM $wpdb->posts as posts
  JOIN $wpdb->postmeta as postmeta
  ON postmeta.post_id = posts.ID
  AND postmeta.meta_key = 'Mood'
  GROUP BY postmeta.meta_key
");
 

Si quoi que ce soit,c'est un début.

the fastest way would be a custom sql query and i'm not sure but you can try

$wpdb->get_results("
  SELECT posts.* , COUNT(*) 'moodcount'
  FROM $wpdb->posts as posts
  JOIN $wpdb->postmeta as postmeta
  ON postmeta.post_id = posts.ID
  AND postmeta.meta_key = 'Mood'
  GROUP BY postmeta.meta_key
");

If anything then its a start.

Pour obtenirtoutes les valeursmétapar une cléméta

Vérifiez wp-> db wordpress codex

 $values = $wpdb->get_col("SELECT meta_value
    FROM $wpdb->postmeta WHERE meta_key = 'yourmetakey'" );
 

For getting all meta values by a meta key

Check wp->db wordpress codex

$values = $wpdb->get_col("SELECT meta_value
    FROM $wpdb->postmeta WHERE meta_key = 'yourmetakey'" );

Iln'y a aucune raisonpour que vousne puissiezpasfusionner le codet31oset Bainternetpour avoir uneinstructionpréparée réutilisable (style wordpress) qui renvoie lenombreet les valeursen une seule opérationefficace.

C'est une requêtepersonnaliséemaiselle utilisetoujours la couche d'abstraction de labase de données wordpress -parexemple,peuimporte ce que sont réellement lesnoms detable,ou s'ils changent,et c'est uneinstructionpréparée,doncnous sommes d'autantplus sûrs Attaques SQL,etc.

Dans ce cas,je ne vérifieplus letype depublicationet j'exclus les chaînes vides:

     $r = $wpdb->get_results(  $wpdb->prepare( "
        SELECT pm.meta_value AS name, count(*) AS count  FROM {$wpdb->postmeta} pm
        LEFT JOIN {$wpdb->posts} p ON p.ID = pm.post_id
        WHERE pm.meta_key = '%s'
        AND pm.meta_value != '' 
        AND p.post_type = '%s'
        GROUP BY pm.meta_value
        ORDER BY pm.meta_value          
        ", $key, $type) 
        );
    return $r;
 

Dans ceparticulierest

Cela renverra untableau d'objets comme ceci:

 array  
 0 => 
 object(stdClass)[359]
  public 'name' => string 'Hamish' (length=6)
  public 'count' => string '3' (length=1)
 1 => 
 object(stdClass)[360]
  public 'name' => string 'Ida' (length=11)
  public 'count' => string '1' (length=1)
 2 => 
 object(stdClass)[361]
  public 'name' => string 'John' (length=12)
  public 'count' => string '1' (length=1)
 

There's no reason why you can't merge t31os and Bainternet's code to have a reusable prepared statement (wordpress style) that returns the count and the values in one efficient operation.

It's a custom query but it's still using the wordpress database abstraction layer - so for example it doesn't matter what the table names really are, or if they change, and it's a prepared statement so we're that much safer from SQL attacks etc.

In this instance I'm no longer checking for post type and I'm excluding empty strings:

    $r = $wpdb->get_results(  $wpdb->prepare( "
        SELECT pm.meta_value AS name, count(*) AS count  FROM {$wpdb->postmeta} pm
        LEFT JOIN {$wpdb->posts} p ON p.ID = pm.post_id
        WHERE pm.meta_key = '%s'
        AND pm.meta_value != '' 
        AND p.post_type = '%s'
        GROUP BY pm.meta_value
        ORDER BY pm.meta_value          
        ", $key, $type) 
        );
    return $r;

In this particular is

This will return an array of objects like so:

array  
 0 => 
 object(stdClass)[359]
  public 'name' => string 'Hamish' (length=6)
  public 'count' => string '3' (length=1)
 1 => 
 object(stdClass)[360]
  public 'name' => string 'Ida' (length=11)
  public 'count' => string '1' (length=1)
 2 => 
 object(stdClass)[361]
  public 'name' => string 'John' (length=12)
  public 'count' => string '1' (length=1)

Utilisez ce qui suit avecforeach

  $key = get_post_custom_values( 'key' );
 

Suppose que lenom de votre clé de champpersonnaliséest

Use the following with foreach

 $key = get_post_custom_values( 'key' );

Assumes the named of your custom field key is