TP中统计指定字段的总数

如统计已激活设备数量和未激活设备数量

$condition = [
    ['member_id', '=', $member_id]
];
$field = [
    'count(if(active_member_id > 0, 1, null)) as actived_num',
    'count(if(active_member_id = 0, 1, null)) as unactived_num',
];

$list = $this->where($where)->field($field)->order($order)->select();