= require('mongoose');
let db=mongoose.connect('mongodb://localhost/tenDB', {useNewUrlParser: true}...);
mongoose.connection.on("open",function () {
console.log("数据库连接成功!")...else{
console.log("修改数据失败",err);
}
});*/
//查找数据
/*
* 语法:
* model.find...({查询条件}可选的,{想要显示的字段}可选的,{筛选条件}可选的,function(){});
* */
/*model.find(function (err,res) {...如果有排序,先排序,再做其他的跳过操作
/*model.find({},{name:1,sex:1,age:1,_id:0},{limit:4,skip:1,sort:{age:-1}},function