mongoose legion

Data Relationship mapping: ORMO:objectR:relationM:mappingThe operation of the database is the equivalent of manipulating the database by encapsulating it into the object and manipulating the object.Installation:NPM Install MongooseUsage examples:Const Mongoose=require (' Mongoose ')1. Connect to the databaseMongoose.connect (' mongodb://127.0.0.1:27017/edu ')2. Design the model structureConst Catschema=

There is no join feature in MongoDB, so joins and associated queries cannot be used with joins, the populate method is encapsulated in mongoose, and the field (property) can be specified as a reference to another schema when defining a schema. When querying a document, you can use the Populate method to find the specified field value for another document or document that is associated by referencing the Schema and ID. Here is a simple chestnut:"Scene"

Plug - insSchemas are pluggable, that is, they can apply pre-packaged capabilities to extend their functionality. This is a very powerful feature.Suppose we have several collection in our database, to add the last-modified functionality to them. It's easy to use plugins. Just create a plug-in and apply it to each schema://Lastmod.jsModule.exports = exports =functionlastmodifiedplugin (schema, options) {Schema.add ({lastmod:date}) Schema.pre (' Save ',function(next) { This. Lastmod =NewDate Next

Models is a constructor that is compiled from the Schema definition. Examples of these model represent documents that can be stored and retrieved from the database. All document creation and retrieval in the database is handled by these model.1. Compile the first modelvar New Mongoose. Schema ({name: ' string ', Size: ' String ' }); var Tank = Mongoose.model (' Tank ', schema);The first parameter is the singular name of the model corresponding to the

Tags: cno mongodb no pretty expr established name mode TPS Operate with MongoDB via Mongoose. The mongoose is created by the model to create the corresponding collection in MongoDB, so that you pass the following code: mongoose.model(‘User‘, UserSchema); When creating a collection in the corresponding database, the first reaction will certainly infer that a ' User ' collection, but the fact is completely di

1. Intro At the node end, the Express HTTP boot and Mongoose MongoDB connections are asynchronous, so it is encountered that when the Web site is opened, the database is not connected, causing a query error, or encountering the database already connected, but the HTTP service has failed to start. There is a more complicated use scenario: first, link the database, then middleware (such as query fixed configuration, such as site title, Administrator inf

Tags: Verify options note localhost crud pre type unique MonThis article focuses on installing the basic tutorial using Mongoose to let node. js operate MongoDB, front-end js+ back-end Node+js Operation MongoDB is the so-called most popular kind of JavaScript full stack development program, need friends can refer to the next Installing Mongoose To prepare a TESTMONGODB project using Express, the command seq

Tags: packaging username font database Image Nodejs Mic Install valueMongoDB Introduction: MongoDB is a JavaScript-based database, the storage format is JSON, and node is a JavaScript-based environment (library), so node and MongoDB collocation can reduce the time and space cost of data conversion. Mongoose Introduction: is a MongoDB object Model tool that transforms data from a database into JavaScript objects for you to use in your application, enc

Mongoose Library in short, a convenient package for manipulating MongoDB databases in the node environment, an object model tool similar to Orm,mongoose converts data from a database into JavaScript objects for you to use in your app.Of course, you have to install the Environment node. js and MongoDB = "MongoDB installationMongoDB is one of the most popular NoSQL databases, developed specifically for node.

1. Define ShcemaIn Mongoose everything starts with the schema. Each schema corresponds to a MongoDB collection and defines the model of documents in that collection.var mongoose = require (' Mongoose '); var Schema = Mongoose. Schema; var New Schema ({ title: string, author:string, body: string, comments: [{body

Mongoose: how to solve the problem that unique does not take effect and how to remove the unique restriction, mongooseunique Preface Unique is a member of schema Constraints Verification. Its role is to make the value of a field unique (cannot be repeated) To keep the field unique, use the type value:{type:String,unique:true,dropDups: true} Note:Once mongoose modifies the data storage organization, the data

Reprinted Please note:Theviper http://www.cnblogs.com/TheViper Let's take a look at the following example. This. login = function *(){....... VaR q = usermodel. findone ({Email: name, PWD: Pwd}); q. select ('_ id'); q.exe C (function (ERR, ID) {If (ERR) return handleerror (ERR); this. body = ID ;});} This is an Ajax login, but the response will return not found. The crux of the problem is that no response is returned. Why is no response returned? This is also quite easy to understand. Becau

Document can be retrieved through some model static helper methods.Any model method that involves specifying a query condition can be executed in two ways.When a callback function:is passed, the operation executes immediately and the result is passed to the callback.is not passed, returns a query instance, which provides a special query generation interface.In Mongoose 4,Query has the then () function, so it can be used as a promise.When a query is ex

1 {2 "__v": 1,3 " _id": "538f5f0f6195a184108c8bd8",4 " title": "GameTitle",5 "Item": [{6 " _id": "538f5f0f6195a184108c8bd6",7 "name": "ItemOne",8 "Men": [{9 " _id": "5390cccf0a84f41f37082874",Ten "user": "id22222222", One "Score": A }, { - " _id": "2390cccf0a84f41f37082873", - "user": "id33333333", the "Score": - }] - }, { - " _id": "538f5f0f6195a184108c8bd7", + "name": "Itemtwo", - "Men": [] + }], A "status": 1 at } - - - //code is: - var menschema = new

1. How to start the MongoDB databaseReference Address: http://www.runoob.com/mongodb/mongodb-window-install.htmlIn the location of the database installation, the Bin folder, enter Mongod--dbpath d:\data\dbD:\data\db is the folder where the data is saved2. Code1 varMongoose=require ('Mongoose');2 3 //connecting to a database4Mongoose.connect ('Mongodb://localhost/shu');5 //Create schema6 varSchema=Mongoose.

No nonsense, direct----------------------。 If your application uses only one database, you should use Mongoose.connect. If you need to create additional connections, use Mongoose.createconnection. var mongoose = require (' Mongoose '); Mongoose.connect (Mongodb://localhost/chihuo);The Mongoose.createconnection return value is a new connection. If you open a separate connection using mongoose.createconnectio

noun explanation Schema: A database model skeleton stored as a file, not capable of database operation Model: The Schema model generated by the publication, database operations with abstract properties and behaviors From the Cnode community1. Create a local database and connect:var mongoose = require (' Mongoose ');　　　　　Get Mongoose Module Mongo

Label:Mongoose Library in short, a convenient package for manipulating MongoDB databases in the node environment, an object model tool similar to Orm,mongoose converts data from a database into JavaScript objects for you to use in your app. Of course, you have to install the Environment node. js and MongoDB = "MongoDB installation MongoDB is one of the most popular NoSQL databases, developed specifically for node. JS, and understands the difference be

Built-in PromisesMongoose asynchronous operations, like. Save () and queries, return promises/a+ conformant Promises. This means the can do things like Mymodel.findone ({}). then () and yield Mymodel.findone ({}). EXEC () (If you ' re using CO ).This means that you can do something like Mymodel.findone ({}). then () and yield Mymodel.findone ({}). exec (if you're using CO)For backwards compatibility, Mongoose 4 returns mpromise promise by default. va

Objective After watching the node.js actual combat, which in the data storage part of the Redis, Mongodb, I also wrote the book according to the introduction of a few simple demo, in the demo process first encountered the problem is the type of data and common curd writing. There are two ways to mongodb common operations, one is to use the API directly, and the same is that you use T-SQL to write SQL statements to manipulate the data, and then use the Mongo