1 //数据库 user
 2 {
 3   uid: 666,
 4   name: "柚子",
 5   lv: 10,
 6   group: 888
 7 },
 8 {
 9   ......
10 }

 1 // GetUserInfo.js
 2 GetUI(o){
 3 
 4   let uid = Number(o.uid) || [] // 666
 5   let name = o.name || [] // ‘柚子‘
 6   let lv = Number(o.lv) || [] // 空
 7   let group = o.group || [] // 空
 8 
 9   // group & lv 为空时
10   if (group == ‘‘ && lv == ‘‘) {
11     db.collection(‘user‘)
12       .where({
13         uid: _.in(uid), // 筛id
14         name: _.in(name) // 筛名字
15       })
16       .get()
17       .then(res => {
18         console.log("返回:", res.data)
19       })
20       .catch(err => {
21         console.log("错误:", err);
22       })
23   } else if (group != ‘‘ && lv == ‘‘) { //group不为空 & lv 为空时
24     db.collection(‘user‘)
25       .where({
26         uid: _.in(uid), // 筛id
27         name: _.in(name), // 筛名
28         group: _.in(group) // 筛组
29       })
30       .get()
31       .then(res => {
32         console.log("返回:", res.data)
33       })
34       .catch(err => {
35         console.log("错误:", err);
36       })
37   } else if (group == ‘‘ && lv != ‘‘) { //group为空 & lv 不为空时
38     db.collection(‘user‘)
39       .where({
40         uid: _.in(uid), // 筛id
41         name: _.in(name), // 筛名
42         lv: _.in(lv) // 筛级
43       })
44       .get()
45       .then(res => {
46         console.log("返回:", res.data)
47       })
48       .catch(err => {
49         console.log("错误:", err);
50       })
51   }
52 }

 1 let condition = {
 2   uid: _.in(uid), 
 3   name: _.in(name)
 4 };
 5 if(group == ‘‘ && lv != ‘‘) {
 6    condition.iv = _.in(lv);
 7 }else {
 8   ...
 9 }
10 ?
11 db.collection(‘test‘).where(condition).get()