我有一个包含这些值的数组（包括撇号）：

\'course_3202\',\'course_3201\',\'course_3200\',\'course_3199\'

我尝试从Posteta表中的这些值中获取结果。

SELECT * FROM wp_postmeta WHERE meta_key IN (%s) and meta_value=1

我没有得到结果（是的，有数据，我应该得到结果）

RESULT = Array ( )

我的代码如下所示：

function get_count_courses_array(array $courseids) {    
    $tmp = array();
    foreach($courseids as $cid) {
        $tmp[] = "\'" . $cid . "\'";
    }    
    $courseids = implode(\',\',$tmp);

    global $wpdb;
    $sql = "SELECT * FROM $wpdb->postmeta";
    $sql .= " WHERE meta_key IN (%s) and meta_value=1";        
    $result = $wpdb->get_results($wpdb->prepare( $sql, $courseids));

    return $result;    
}

在phpMyAdmin中，我尝试了同样的方法，并得到了结果（如预期的那样）：

SELECT * FROM wp_postmeta WHERE meta_key IN (\'course_3202\',\'course_3201\',\'course_3200\',\'course_3199\') and meta_value=1

What am I doing wrong?

$a = array(\'course_3202\',\'course_3201\',\'course_3200\',\'course_3199\');

$b = array_fill(0,count($a),\'%s\');
$b = implode(\',\',$b);

$sql = "SELECT * FROM $wpdb->postmeta";
$sql .= " WHERE meta_key IN ({$b}) and meta_value=1";    

var_dump($wpdb->prepare($sql,$a));

$courseids = array( \'course_3202\', \'course_3201\', \'course_3200\', \'course_3199\' );
$meta_query = array();

foreach( $courseids as $courseid ){
    $meta_query[] = array( 
                              \'key\'   => $courseid,
                              \'value\' => \'1\',
                              \'compare\' => \'IN\',
                         );
}   

$args = array(
    \'post_type\' => \'post\',
    \'meta_query\' => array(
                       $meta_query
               )
);
$query = new WP_Query( $args );

$count_courses = $query->found_posts;