node.js calls mongoose's aggregate function

After the following example is executed successfully, the table in mongodb is tests, and a character "s" is automatically added. This is a pit! ! !

 

 var mongoose = require("mongoose");  

  mongoose.connect("mongodb://192.168.1.17:27017/test",function(e){
  if(e)
      console.log(e.message);
  
  console.log("connect ok!");
  
});


  var Schema = mongoose.Schema; // Create a model
  var userScheMa = new Schema({
    carrier: String,
    lang: String,
    impCount: Number,
    clickCount: Number,

  }); // A new model is defined, but this model also Not associated with the test_table collection


var data = mongoose.model('test_table', userScheMa); // Associated with the test_table collection


exports.query = function(req, res){
var key1 = {carrier: "$carrier", lang: "$lang"}
var query1 = {'$or': [{'impCount': {'$gt': 3}}, {'impCount': {'$lt' : 16}}] }
var sort1 =  { os: -1 }
var limit1 = 3
var skip1 = 0


data.aggregate(
[
       { $match:  query1},
       { $group:  { _id: key1 , ImpCount: { $sum: "$impCount" }, ClickCount:{$sum: "$clickCount" }}},
       { $sort:   sort1},
       { $limit:  limit1 },
       { $skip :  skip1}
],function(e,docs)
{
   if(e)
       console.log(e.message);
   res.send(JSON.stringify(docs));
}
);  
};