Nodejs访问MongoDB

xuol001

　　Setting.js[用于保存数据库信息]

module.exports = {
name : 'ZMessage',
host : 'localhost'
}

　　name为数据库名称，host为数据库访问地址。
　　DBHelper.js[具体访问数据库的方法]

function DBHelper(){
this.dbSetting = require('./DBSettings.js');
this.Db = require('mongodb').Db;
this.Connection = require('mongodb').Connection;
this.Server = require('mongodb').Server;
this.GetDBExecutor = function(){
return new this.Db(this.dbSetting.name, new this.Server(this.dbSetting.host, this.Connection.DEFAULT_PORT, {}),{safe:false});
};
//获取所有用户信息
this.getAllUser = function(callback){
var executor = this.GetDBExecutor();
executor.open(function(err, db) {
if (err) {
return callback(err);
}
db.collection('UserInfo', function(err, collection) {
if (err) {
executor.close();
return callback(err);
}
collection.find({}).toArray(function(err,items){
executor.close();
items.forEach(function(item, index) {
console.log(item.userName);
});
});
});
});
}
//添加用户信息
this.addUser = function(user,callback){
var executor = this.GetDBExecutor();
executor.open(function(err, db) {
if (err) {
return callback(err);
}
db.collection('UserInfo', function(err, collection) {
console.log(4);
if (err) {
executor.close();
return callback(err);
}
collection.insert(user, {safe: true}, function(err, user) {
executor.close();
});
});
});
}
//添加用户信息
this.updateUser = function(user, callback){
var executor = this.GetDBExecutor();
executor.open(function(err, db){
if (err) {
return callback(err);
}
db.collection('UserInfo', function(err, collection){
if (err) {
executor.close();
return callback(err);
}
collection.update({
"userId": user.userId
}, {
$set: {
userName: "更改后"
}
}, {
saft: false,
upsert: true
}, function(err, user){
executor.close();
});
});
});
}
//删除用户信息
this.deleteUser = function(userId,callback){
var executor = this.GetDBExecutor();
executor.open(function(err, db) {
if (err) {
return callback(err);
}
db.collection('UserInfo', function(err, collection) {
if (err) {
executor.close();
return callback(err);
}
collection.remove({"userId":userId},{saft:false},function(err, user) {
executor.close();
});
});
});
}
}
module.exports = new DBHelper();
　　假设已经存在UserInfo集合。
　　app.js启动文件用于测试

var dbclient = require('./DBHelper/DBHelper');
dbclient.addUser({userId:3,userName:'李四',userStatus : false},function(err){
console.log(err);
});
dbclient.getAllUser(function(err){
console.log(err);
});
dbclient.updateUser({userId:3,userName:'李四',userStatus : true},function(err){
console.log(err);
});
dbclient.deleteUser(3,function(err){
console.log(err);
});
　　关于更新，有几种更新方式

Fields


Name
Description

[size=1.04em]$inc
Increments the value of the field by the specified amount.


[size=1.04em]$rename
Renames a field.


[size=1.04em]$setOnInsert
Sets the value of a field upon documentation creation during an upsert. Has no effect on update operations that modify existing documents.


[size=1.04em]$set
Sets the value of a field in an existing document.


[size=1.04em]$unset
Removes the specified field from an existing document.



Array

Operators


Name
Description

[size=1.04em]$
Acts as a placeholder to update the first element that matches the query condition in an update.


[size=1.04em]$addToSet
Adds elements to an existing array only if they do not already exist in the set.


[size=1.04em]$pop
Removes the first or last item of an array.


[size=1.04em]$pullAll
Removes multiple values from an array.


[size=1.04em]$pull
Removes items from an array that match a query statement.


[size=1.04em]$pushAll

Deprecated. Adds several items to an array.


[size=1.04em]$push
Adds an item to an array.



Modifiers


Name
Description

[size=1.04em]$each
Modifies the [size=1.04em]$push and [size=1.04em]$addToSet operators to append multiple items for array updates.


[size=1.04em]$slice
Modifies the [size=1.04em]$push operator to limit the size of updated arrays.


[size=1.04em]$sort
Modifies the [size=1.04em]$push operator to reorder documents stored in an array.





Bitwise


Name
Description


[size=1.04em]$bit
Performs bitwise [size=1.04em]AND and [size=1.04em]OR updates of integer values.



Isolation


Name
Description


[size=1.04em]$isolated
Modifies behavior of multi-updates to improve the isolation of the operation.