thinkphp5.1 in 范围查询实例

场景：category_ids 值为1,2,4
查询 category_ids = 2 和 4的所有记录
查询语句：
$map['category_id']=array('in',$category_ids)❌

$category_ids =1,2,3

$map[] =['category_id','in',$category_ids]; ✔