FIND IN SET函数
来自维基鲸
category_ids字段：2,4,8,13,25
原生SQL：
select * from table where FIND_IN_SET('13',category_ids)
ThinkPHP
$category_ids = 13;
$where[] = ['exp', Db::raw("FIND_IN_SET($category_ids,category_ids)")];
category_ids字段：2,4,8,13,25
select * from table where FIND_IN_SET('13',category_ids)
$category_ids = 13;
$where[] = ['exp', Db::raw("FIND_IN_SET($category_ids,category_ids)")];
