添加将数据库连接到Express应用程序的功能只是为应用程序中的数据库加载适当的Node.js驱动程序。本文档简要介绍了如何在Express应用程序中为数据库系统添加和使用一些最流行的Node.js模块：

• Cassandra

• Couchbase

• CouchDB

• LevelDB

• MySQL

• MongoDB

• Neo4j

• Oracle

• PostgreSQL

• Redis

• SQL Server

• SQLite

• ElasticSearch

这些数据库驱动程序有很多可用的。对于其他选项，请在npm站点上搜索。

Cassandra

模块：cassandra-driver

安装

$ npm install cassandra-driver

示例

var cassandra = require('cassandra-driver') var client = new cassandra.Client({ contactPoints: ['localhost'] }) client.execute('select key from system.local', function (err, result) { if (err) throw err console.log(result.rows[0])})

Couchbase

模块：couchnode

安装

$ npm install couchbase

示例

var couchbase = require('couchbase') var bucket = (new couchbase.Cluster('http://localhost:8091')).openBucket('bucketName') // add a document to a bucketbucket.insert('document-key', { name: 'Matt', shoeSize: 13 }, function (err, result) { if (err) { console.log(err) } else { console.log(result) }})// get all documents with shoe size 13 var n1ql = 'SELECT d.* FROM `bucketName` d WHERE shoeSize = $1' var query = N1qlQuery.fromString(n1ql)bucket.query(query, [13], function (err, result) { if (err) { console.log(err) } else { console.log(result) }})

CouchDB

模块：nano

安装

$ npm install nano

示例

var nano = require('nano')(' var books = nano.db.use('books') // Insert a book document in the books databasebooks.insert({ name: 'The Art of war' }, null, function (err, body) { if (err) { console.log(err) } else { console.log(body) }})// Get a list of all booksbooks.list(function (err, body) { if (err) { console.log(err) } else { console.log(body.rows) }})

LevelDB

模块：levelup

安装

$ npm install level levelup leveldown

示例

var levelup = require('levelup')var db = levelup('./mydb')db.put('name', 'LevelUP', function (err) { if (err) return console.log('Ooops!', err) db.get('name', function (err, value) { if (err) return console.log('Ooops!', err) console.log('name=' + value) })})

MySQL

模块：mysql

安装

$ npm install mysql

示例

var mysql = require('mysql')var connection = mysql.createConnection({ host : 'localhost', user : 'dbuser', password : 's3kreee7', database : 'my_db'});connection.connect()connection.query('SELECT 1 + 1 AS solution', function (err, rows, fields) { if (err) throw err console.log('The solution is: ', rows[0].solution)})connection.end()

MongoDB

Module: mongodb

安装

$ npm install mongodb

示例

var MongoClient = require('mongodb').MongoClient MongoClient.connect('mongodb://localhost:27017/animals', function (err, db) { if (err) throw err db.collection('mammals').find().toArray(function (err, result) { if (err) throw err console.log(result) })})

如果你想要一个MongoDB的对象模型驱动程序，看看Mongoose。

Neo4j

模块：apoc

安装

$ npm install apoc

示例

var apoc = require('apoc')apoc.query('match (n) return n').exec().then( function (response) { console.log(response) }, function (fail) { console.log(fail) })

Oracle

模块：oracledb

安装

注：请参阅安装先决条件。

$ npm install oracledb

示例

const oracledb = require('oracledb');const config = { user: '', // Update me password: '', // Update me connectString: 'localhost:1521/orcl' // Update me};async function getEmployee(empId) { let conn; try { conn = await oracledb.getConnection(config); const result = await conn.execute( 'select * from employees where employee_id = :id', [empId] ); console.log(result.rows[0]); } catch (err) { console.log('Ouch!', err); } finally { if (conn) { // conn assignment worked, need to close await conn.close(); } }} getEmployee(101);

PostgreSQL

模块：pg-promise

安装

$ npm install pg-promise

示例

var pgp = require('pg-promise')(/*options*/) var db = pgp('postgres://username:password@host:port/database')db.one('SELECT $1 AS value', 123) .then(function (data) { console.log('DATA:', data.value) }) .catch(function (error) { console.log('ERROR:', error) })

Redis

模块：redis

安装

$ npm install redis

示例

var client = require('redis').createClient()client.on('error', function (err) { console.log('Error ' + err)}) client.set('string key', 'string val', redis.print) client.hset('hash key', 'hashtest 1', 'some value', redis.print) client.hset(['hash key', 'hashtest 2', 'some other value'], redis.print)client.hkeys('hash key', function (err, replies) { console.log(replies.length + ' replies:') replies.forEach(function (reply, i) { console.log(' ' + i + ': ' + reply) }) client.quit()})

SQL Server

模块：tedious

安装

$ npm install tedious

示例

var Connection = require('tedious').Connection;var Request = require('tedious').Request;var config = { userName: 'your_username', // update me password: 'your_password', // update me server: 'localhost'} var connection = new Connection(config); connection.on('connect', function(err) { if (err) { console.log(err); } else { executeStatement(); }}); function executeStatement() { request = new Request("select 123, 'hello world'", function(err, rowCount) { if (err) { console.log(err); } else { console.log(rowCount + ' rows'); } connection.close(); }); request.on('row', function(columns) { columns.forEach(function(column) { if (column.value === null) { console.log('NULL'); } else { console.log(column.value); } }); }); connection.execSql(request);}

SQLite

模块：sqlite3

安装

$ npm install sqlite3

示例

var sqlite3 = require('sqlite3').verbose() var db = new sqlite3.Database(':memory:')db.serialize(function () { db.run('CREATE TABLE lorem (info TEXT)') var stmt = db.prepare('INSERT INTO lorem VALUES (?)') for (var i = 0; i < 10; i++) { stmt.run('Ipsum ' + i) } stmt.finalize() db.each('SELECT rowid AS id, info FROM lorem', function (err, row) { console.log(row.id + ': ' + row.info) })})db.close()

ElasticSearch

模块：elasticsearch

安装

$ npm install elasticsearch

示例

var elasticsearch = require('elasticsearch') var client = elasticsearch.Client({ host: 'localhost:9200'})client.search({ index: 'books', type: 'book', body: { query: { multi_match: { query: 'express js', fields: ['title', 'description'] } } }}).then(function (response) { var hits = response.hits.hits}, function (error) { console.trace(error.message)})