第一次进行自定义查询。我在寻找一种方法来获取某个分类法的类别列表，以便可以为自动完成函数运行类似的查询。为了得到一些结果，我提出了mysql查询，它在phpMyAdmin中给出了结果

SELECT * 
FROM wp_terms
INNER JOIN wp_term_taxonomy ON ( wp_terms.term_id = wp_term_taxonomy.term_id ) 
WHERE wp_terms.name LIKE  \'ca%\'
AND count >0
LIMIT 0 , 30

我的wordpress函数如下所示

function get_categories_by_like_searching() {
    global $wpdb;
    $keyword = $_GET[\'query\']; // example : "ca" would return categories with name of "cats"
    $query = $wpdb->prepare( "SELECT * FROM $wpdb->wp_terms 
                                INNER JOIN $wpdb->wp_term_taxonomy 
                                    ON ($wpdb->wp_terms.term_id = $wpdb->wp_term_taxonomy.term_id) 
                                WHERE $wpdb->wp_terms.name LIKE %s AND $wpdb->wp_terms.count > 0", $wpdb->esc_like($keyword) . \'%\');
    $categories = $wpdb->query($query);
    foreach($categories as $category) { 
        array_push($results,$category[\'name\']);
    }
    $results = array("suggestions"=>$results);
    $response = json_encode($results);
    // response output
    header( "Content-Type: application/json" );
    echo $response;
    exit;
}

我是否连接错误，或者wordpress查询语法是否已关闭？

我要寻找的确切函数实际上是：

<?php 

$args = array(
    \'taxonomy\'                 => \'my_custom_taxonomy\'
     // with category names LIKE \'x%\'

); 
$categories = get_categories($args);
?>

$query = $wpdb->prepare( "SELECT * FROM $wpdb->wp_terms INNER JOIN $wpdb->wp_term_taxonomy ON ($wpdb->wp_terms.term_id = $wpdb->wp_term_taxonomy.term_id) WHERE $wpdb->wp_terms.name LIKE %s AND $wpdb->wp_terms.count > 0", $wpdb->esc_like($keyword) . \'%\');

$query = $wpdb->prepare( "SELECT * FROM $wpdb->terms INNER JOIN $wpdb->term_taxonomy ON ($wpdb->terms.term_id = $wpdb->term_taxonomy.term_id) WHERE $wpdb->terms.name LIKE %s AND $wpdb->terms.count > 0", $wpdb->esc_like($keyword) . \'%\');