MySQL查询时，查询结果如何按照where in数组排序
在查询中，MySQL默认是order by id asc排序的，但有时候需要按照where in 的数组顺序排序，比如where in的id查询数组为[922,106,104,103],正常情况查询出来的结果顺序为[103,104,106,922],这可能不是我们想要的结果，
我们期望查出来的结果顺序与where in的顺序一致，这里介绍两个方式：
1.使用find_in_set函数:
select * from table where id in (922,106,104,103) order by find_in_set(id,'922,106,104,103');
2.使用order by field
select * from table where id in (922,106,104,103) order by field(id,922,106,104,103);
下面是在tp5中的实现过程
1 $path = '103-104-106-922';
2 $arr = explode('-',$path);
3 dump($arr);
4 $new_arr = array_reverse($arr);
5 dump($new_arr);
6 $new_arr1 = implode(',',$new_arr);
7 dump($new_arr1);
8 $list = Db::name('member')
9 ->where('id','in',$new_arr1)
10 ->where('type',2)
11 ->field('id,type')
12 //->order("find_in_set(id,$new_arr1)")
13 ->order("field(id,$new_arr1)")
14 ->select();
15 dump($list);die;
查询结果如下所示，可见实现了按照where in 数组顺序进行排序了
1 array(4) {
2 [0] => string(3) "103"
3 [1] => string(3) "104"
4 [2] => string(3) "106"
5 [3] => string(3) "922"
6 }
7 array(4) {
8 [0] => string(3) "922"
9 [1] => string(3) "106"
10 [2] => string(3) "104"
11 [3] => string(3) "103"
12 }
13 string(15) "922,106,104,103"
14 array(4) {
15 [0] => array(2) {
16 ["id"] => int(922)
17 ["type"] => int(2)
18 }
19 [1] => array(2) {
20 ["id"] => int(106)
21 ["type"] => int(2)
22 }
23 [2] => array(2) {
24 ["id"] => int(104)
25 ["type"] => int(2)
26 }
27 [3] => array(2) {
28 ["id"] => int(103)
29 ["type"] => int(2)
30 }
31 }