functions - wordpress add text field to custom post type

Wordpress wp_query group por campo personalizado

Question

Tengo que crear un formulario de búsqueda en el que deba completar una selección por estado de los tipos de mensajes personalizados. Algunos de ellos tienen el mismo estado, entonces me gustaría agruparme para tener una lista de estados seleccionada limpia. He hecho esto:

<?php
    function  query_group_by_filter($groupby){
        global $wpdb;
        return $wpdb->postmeta.".meta_key = ''state''";
    }
?>
<?php add_filter(''posts_groupby'', ''query_group_by_filter''); ?>
<?php $states = new WP_Query(array(''post_type'' => ''observatoire'')); ?>
<?php remove_filter(''posts_groupby'', ''query_group_by_filter''); ?>
<select id="" class="" name="siege_pays" >
     <option value=""></option>
<?php
while ( $states->have_posts() ) : $states->the_post();
echo "<option value=".get_field_object(''state'').">".get_field_object(''state'')."</option>"; 
endwhile;
?>
</select>

la consulta de resultado no funciona .. Ayuda por favor :)

''SELECT SQL_CALC_FOUND_ROWS  wp_posts.ID FROM wp_posts  WHERE 1=1  AND wp_posts.post_type = ''observatoire'' AND ((wp_posts.post_status = ''publish'' OR wp_posts.post_status = ''private'') OR wp_posts.post_status = ''private'') GROUP BY wp_postmeta.meta_key = ''siege_pays'' ORDER BY wp_posts.post_date DESC LIMIT 0, 10''

Answer 1

Puedes probar el siguiente código:

<?php
    function  query_group_by_filter($groupby){
       global $wpdb;

       return $wpdb->postmeta . ''.meta_key = "state"'';
    }
?>
<?php add_filter(''posts_groupby'', ''query_group_by_filter''); ?>
<?php $states = new WP_Query(array(
    ''post_type'' => ''observatoire'',
    ''post_status'' => ''publish'',
    ''posts_per_page'' => -1,
    ''meta_key'' => ''state''
)); 
?>
<?php remove_filter(''posts_groupby'', ''query_group_by_filter''); ?>
<select id="" class="" name="siege_pays" >
     <option value=""></option>
<?php
while ( $states->have_posts() ) : $states->the_post();
echo "<option value=".get_field_object(''state'').">".get_field_object(''state'')."</option>"; 
endwhile;
?>
</select>

Consulta:

SELECT   wp_posts.* FROM wp_posts  INNER JOIN wp_postmeta ON (wp_posts.ID = wp_postmeta.post_id) WHERE 1=1  AND wp_posts.post_type = ''observatoire'' AND (wp_posts.post_status = ''publish'') AND (wp_postmeta.meta_key = ''state'' ) GROUP BY wp_postmeta.meta_key = "state" ORDER BY wp_posts.post_date DESC 

Answer 2

Tuve que hacer algunas mejoras al Código Chirag Patels, para que funcione:

<?php
    function  query_group_by_filter($groupby){
       global $wpdb;

       return $wpdb->postmeta . ''.meta_value '';
    }
?>
<?php add_filter(''posts_groupby'', ''query_group_by_filter''); ?>
<?php $states = new WP_Query(array(
    ''post_type'' => ''observatoire'',
    ''post_status'' => ''publish'',
    ''posts_per_page'' => -1,
    ''meta_key'' => ''state''
)); 
?>
<?php remove_filter(''posts_groupby'', ''query_group_by_filter''); ?>
<select id="" class="" name="siege_pays" >
     <option value=""></option>
<?php
while ( $states->have_posts() ) : $states->the_post();
echo "<option value=".reset(get_post_custom_values(''state'')).">".reset(get_post_custom_values(''state''))."</option>"; 
endwhile;
?>
</select>