node操作mongodb封装
2019-11-05 本文已影响0人
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const MongoDb = require('mongodb');
const MongoClient=MongoDb.MongoClient;
const ObjectID = MongoDb.ObjectID;
const Config=require('./config.js')
class Db{
//单例模式
static getInstance(){
if(!Db.Instance){
Db.Instance=new Db()
}
return Db.Instance
}
constructor(){
this.dbClient=null
this.connect()
}
connect(){
const client = new MongoClient(Config.dbUrl,{ useNewUrlParser: true });
return new Promise((resolve,reject) =>{
if(!this.dbClient){
client.connect(err=>{
if(err){
reject(err)
}
else{
const db = client.db(Config.dbName);
this.dbClient = db
resolve(this.dbClient)
}
})}
else{
resolve(this.dbClient)
}
})
}
find(collectionName,json){
return new Promise((resolve,reject)=>{
this.connect().then(function(db){
var result = db.collection(collectionName).find(json)
result.toArray((err,docs)=>{
if(err){
reject(err)
}else{
resolve(docs)
}
})
})
})
}
insert(collectionName,json){
return new Promise((resolve,reject)=>{
this.connect().then(db=>{
db.collection(collectionName).insertOne(json,(err,result)=>{
if(err){
reject(err)
}else{
resolve(result)
}
})
})
})
}
update(collectionName,where,data){
return new Promise((resolve,reject)=>{
this.connect().then(db=>{
db.collection(collectionName).updateOne(where,{
$set:data
},(err,result)=>{
if(err){
reject(err)
}else{
resolve(result)
}
})
})
})
}
remove(collectionName,where){
return new Promise((resolve,reject)=>{
this.connect().then(db=>{
db.collection(collectionName).removeOne(where,(err,result)=>{
if(err){
reject(err)
}else{
resolve(result)
}
})
})
})
}
getObjectId(id){
return new ObjectID(id)
}
}
module.exports=Db.getInstance()