Nodejs访问MongoDB
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
$inc
Increments the value of the field by the specified amount.
$rename
Renames a field.
$setOnInsert
Sets the value of a field upon documentation creation during an upsert. Has no effect on update operations that modify existing documents.
$set
Sets the value of a field in an existing document.
$unset
Removes the specified field from an existing document.
Array
Operators
Name
Description
$
Acts as a placeholder to update the first element that matches the query condition in an update.
$addToSet
Adds elements to an existing array only if they do not already exist in the set.
$pop
Removes the first or last item of an array.
$pullAll
Removes multiple values from an array.
$pull
Removes items from an array that match a query statement.
$pushAll
Deprecated. Adds several items to an array.
$push
Adds an item to an array.
Modifiers
Name
Description
$each
Modifies the $push and $addToSet operators to append multiple items for array updates.
$slice
Modifies the $push operator to limit the size of updated arrays.
$sort
Modifies the $push operator to reorder documents stored in an array.
Bitwise
Name
Description
$bit
Performs bitwise AND and OR updates of integer values.
Isolation
Name
Description
$isolated
Modifies behavior of multi-updates to improve the isolation of the operation.
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