比如要根据下面这个数据库的collects的某个值查询：

    1. var UserSchema =new Schema({
    2.     name:String,
    3.     collects:[
    4.         {
    5.             pic:String,
    6.             title:String,
    7.             raiting:String,
    8.             slogo:String,
    9.             evaluate:String,
    10.             labels:Array,
    11.             collected:Boolean
    12.         }
    13.     ],
    14.   })

    语法：

    1. var isHave = await UserModel.find({"collects.pic":这里是要查询的值});