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如何使用mongoose检索mongodb数据_Mongodb_Mongoose - Fatal编程技术网

如何使用mongoose检索mongodb数据

如何使用mongoose检索mongodb数据,mongodb,mongoose,Mongodb,Mongoose,我正在学习Pluralsight课程,但这段代码不起作用。控制台中出现错误: mongoMessage=messageDoc.message; ^ TypeError:无法读取null的属性“message” mongoose.connect('mongodb://localhost:multivision'); var db=猫鼬连接; db.on('error',console.error.bind(console,'connectionerror…'); db.once('open',函数

我正在学习Pluralsight课程,但这段代码不起作用。控制台中出现错误:

mongoMessage=messageDoc.message; ^ TypeError:无法读取null的属性“message”

mongoose.connect('mongodb://localhost:multivision');
var db=猫鼬连接;
db.on('error',console.error.bind(console,'connectionerror…');
db.once('open',函数回调(){
console.log('multivisiondb opened');
});
var messageSchema=mongoose.Schema({message:String});
var Message=mongoose.model('Message',messageSchema);
var mongoMessage;
Message.findOne().exec(函数(err,messageDoc){
mongoMessage=messageDoc.message;
});

很可能是因为您在db
multivision的
消息
集合中没有文档

multivision中有集合;运行terminal命令,我得到了以下结果:>使用multivision切换到db multivision>db.messages.insert({message:'Hello Mongo'})WriterResult({“Ninsterted”:1})>show collections messages system.indexes>db.messages.find(){“\u id”:ObjectId(“536BEC338216B27C3348F5C”),“message”:“Hello Mongo”}{“\u id”:ObjectId(“536E3D0B7AC54B7CBFAF847”),“message”:“Hello Mongo”}尝试将您的连接字符串更改为mongodb://localhost:27017/multivision