我正在尝试按当前日期以及事件的开始和结束日期查询自定义帖子类型（事件）。我想有三个选择：现在的，即将到来的和过去的。这是我正在使用的代码，但它工作不正常。

      $current = time();

    switch ($print_type) {
        case \'current\':
            $meta_quer_args = array(
        \'relation\'  =>   \'AND\',
        array(
            \'key\'       =>   \'event-start-date\',
            \'value\'     =>   $current,
            \'compare\'   =>   \'<=\',

        ),
        array(
                    \'key\' => \'event-end-date\',
                    \'value\' => $current,
                    \'compare\' => \'>=\'
                )

    ); 
            break;
        case \'upcoming\':
            $meta_quer_args = array(
        \'relation\'  =>   \'AND\',
        array(
            \'key\'       =>   \'event-start-date\',
            \'value\'     =>   date(),
            \'compare\'   =>   \'>=\',

        )
    );
            break;
        case \'past\':
            $meta_quer_args = array(
        \'relation\'  =>   \'AND\',
        array(
            \'key\'       =>   \'event-start-date\',
            \'value\'     =>   date(),
            \'compare\'   =>   \'<\',

        )
    );
            break;
        default:
            $meta_quer_args = array(
        \'relation\'  =>   \'AND\',
        array(
            \'key\'       =>   \'event-end-date\',
            \'value\'     =>   date(),
            \'compare\'   =>   \'>=\',

        )
    );
            break;
    }

$query_args = array(
    \'post_type\'             =>   \'exhibitions\',
    \'posts_per_page\'        =>   -1,
    \'post_status\'           =>   \'publish\',
     \'ignore_sticky_posts\'   =>   true,
    \'meta_key\'              =>   \'event-start-date\',
    \'orderby\'               =>   \'meta_value_num\',
    \'order\'                 =>   \'DESC\',
    \'meta_query\'            =>   $meta_quer_args
);

$selected_events = new WP_Query( $query_args );