Node. js uses mongoskin to operate mongoDB instances.

Node. js uses mongoskin to operate mongoDB instances.

I. Nonsense

Developed the tourism tag service, Weibo tag retrieval system, map service, and web APP service from March January... use MongoDB scenario from. NET, JAVA environment to node. js platform. The combination of Node. js and mongodb feels better. I feel that mongodb and node. js are born in a pair. Indeed, the mongodb client is the JS parsing engine. Therefore, it is nice to select mongodb and node. js for product prototype. On the Internet, some netizens asked me which driver is the best choice for mongodb development. I used to use the native driver all the time. However, there are many issues to note when writing code, for example, closing a connection... therefore. in the js development environment, I recommend using javasskin.

2. Several concepts to be mentioned

(1) databases: Same as relational databases.
(2) Set: tables in a relational database.
(3) Document: similar to the record of a relational database, it is actually a JSON object.
(4) Database Design: We recommend that you consider NoSQL design and discard the design concept of relational data. In fact, NoSQL database design is profound and requires constant practice in projects.
(5) User System: each database has its own administrator. You can:
Copy codeThe Code is as follows:
Use dbname; db. addUser ('root _ 1', 'test ');

(7) It is recommended to change the external Port
(8) start the service (this is a change in Windows and linux ):
Copy codeThe Code is as follows:
Mongod -- dbpath "XX \ MongoDB \ data \ db" -- logpath "XX \ MongoDB \ log \ mongo. log" -- logappend-auth -- port 7868

3. Build mongodb development infrastructure

(0) npm install strongskin

This section does not introduce Node. js installation, package, and other mechanisms.

(1) Create the configuration file config. json

Copy codeThe Code is as follows:
{
"Dbname": "TEST ",
"Port": "7868 ",
"Host": "127.0.0.1 ",
"Username": "test ",
"Password": "test"
}

(2) create a util related class mongo. js: export a DB object

Copy codeThe Code is as follows:
Var login Skin = require ('login skin '),
Config = require ('./../config. json ');

/*
* @ Des: export the database connection module
**/
Module. exports = (function (){
Var host = config. host,
Port = config. port,
DbName = config. dbname,
UserName = config. username,
Password = config. password,
Str = 'mongodb: // '+ userName +': '+ password +' @ '+ host +': '+ port +'/'+ dbName;

Var option = {
Native_parser: true
};

Return response skin. db (str, option );
})();

(3) construct the basic class of CRUD: To reduce repeated CURD code, you only need to input the relevant JSON object.

Copy codeThe Code is as follows:
Var db = require ('./mongo. js '),
Status = require ('./status '),
Required Skin = require ('your skin ');

Var CRUD = function (collection ){
This. collection = collection;
Db. bind (this. collection );
};

CRUD. prototype = {
/*
* @ Des: Creates a record.
* @ Model: the inserted record. It is a JSON-format model.
* @ Callback: callback. The success or failure information is returned.
*
**/
Create: function (model, callback ){
Db [this. collection]. save (model, function (err, item ){
If (err ){
Return callback (status. fail );
}
Item. status = status. success. status;
Item. message = status. success. message;
Return callback (item );
});
},

/*
* @ Des: Read a record.
* @ Query: query condition. The JSON literal volume queried by Mongo.
* @ Callback: callback, which returns the required record or Failure Information
*
**/
Read: function (query, callback ){
Db [this. collection]. find (query). toArray (function (err, items ){
If (err ){
Return callback (status. fail );
}
Var obj = {
Status: status. success. status,
Message: status. success. message,
Items: items
};

Return callback (obj );
});
},
/*
* @ Des: updates a record.
* @ Query: query condition. The JSON literal volume queried by Mongo. The value is _ id.
* @ UpdateModel: JSON-format model to be updated
* @ Callback: the success or failure message is returned.
*
**/
Update: function (query, updateModel, callback ){
Var set = {set: updateModel };
Db [this. collection]. update (query, set, function (err ){
If (err ){
Return callback (status. fail );
} Else {
Return callback (status. success );
}
});
},

/*
* @ Des: deletes a record.
* @ Query: query condition. The JSON literal volume queried by Mongo.
* @ Callback: returns the failed or successful message.
*
**/
DeleteData: function (query, callback ){
Db [this. collection]. remove (query, function (err ){
If (err ){
Return callback (status. fail );
}
Return callback (status. success );
});
}
};

Module. exports = CRUD;

(4) Build status. json. Because some statuses are required to indicate success and failure, they can be extended to verification code errors, SMS verification errors, username errors, etc.

Copy codeThe Code is as follows:
Module. exports = {
/*
* Successful status
*
**/
Success :{
Status: 1,
Message: 'OK'
},

/*
* Failure status
*
**/
Fail :{
Status: 0,
Message: 'fail'
},

/*
* The two passwords are inconsistent.
**/
RepeatPassword :{
Status: 0,
Message: 'The passwords entered twice are inconsistent'
}
};

Use nodejs to query data in mongodb, and temporarily store the query results in the array docs. How to separate the docs over 16 MB?

1. Only the required data is queried. If other fields are not queried, the query fields are displayed.
2. You can perform segmented queries by a field, such as time, id, and batch query.
3. You can modify the maximum number of queries allowed.
 
Why didn't nodejs return an operation for mongodb?

The code is sent up.