---
layout: page
title: Express でのデータベースの統合
description: Discover how to integrate various databases with Express.js applications, including setup examples for MongoDB, MySQL, PostgreSQL, and more.
menu: guide
order: 11
redirect_from: "  "
---

# データベースの統合

Adding the capability to connect databases to Express apps is just a matter of loading an appropriate Node.js driver for the database in your app. This document briefly explains how to add and use some of the most popular Node.js modules for database systems in your Express app:

- [Cassandra](#cassandra)
- [Couchbase](#couchbase)
- [CouchDB](#couchdb)
- [LevelDB](#leveldb)
- [MySQL](#mysql)
- [MongoDB](#mongodb)
- [Neo4j](#neo4j)
- [Oracle](#oracle)
- [PostgreSQL](#postgresql)
- [Redis](#redis)
- [SQL Server](#sql-server)
- [SQLite](#sqlite)
- [ElasticSearch](#elasticsearch)

<div class="doc-box doc-notice" markdown="1">
These database drivers are among many that are available. For other options,
search on the [npm](https://www.npmjs.com/) site.
</div>

## Cassandra

**モジュール**: [cassandra-driver](https://github.com/datastax/nodejs-driver)

### **インストール**

```bash
$ npm install cassandra-driver
```

### 例

```js
const cassandra = require('cassandra-driver')
const client = new cassandra.Client({ contactPoints: ['localhost'] })

client.execute('select key from system.local', (err, result) => {
  if (err) throw err
  console.log(result.rows[0])
})
```

## Couchbase

**Module**: [couchnode](https://github.com/couchbase/couchnode)

### **インストール**

```bash
$ npm install couchbase
```

### 例

```js
const couchbase = require('couchbase')
const bucket = (new couchbase.Cluster('http://localhost:8091')).openBucket('bucketName')

// add a document to a bucket
bucket.insert('document-key', { name: 'Matt', shoeSize: 13 }, (err, result) => {
  if (err) {
    console.log(err)
  } else {
    console.log(result)
  }
})

// get all documents with shoe size 13
const n1ql = 'SELECT d.* FROM `bucketName` d WHERE shoeSize = $1'
const query = N1qlQuery.fromString(n1ql)
bucket.query(query, [13], (err, result) => {
  if (err) {
    console.log(err)
  } else {
    console.log(result)
  }
})
```

## CouchDB

**モジュール**: [nano](https://github.com/dscape/nano)

### **インストール**

```bash
$ npm install nano
```

### 例

```js
const nano = require('nano')('http://localhost:5984')
nano.db.create('books')
const books = nano.db.use('books')

// Insert a book document in the books database
books.insert({ name: 'The Art of war' }, null, (err, body) => {
  if (err) {
    console.log(err)
  } else {
    console.log(body)
  }
})

// Get a list of all books
books.list((err, body) => {
  if (err) {
    console.log(err)
  } else {
    console.log(body.rows)
  }
})
```

## LevelDB

**モジュール**: [levelup](https://github.com/rvagg/node-levelup)

### **インストール**

```bash
$ npm install level levelup leveldown
```

### 例

```js
const levelup = require('levelup')
const db = levelup('./mydb')

db.put('name', 'LevelUP', (err) => {
  if (err) return console.log('Ooops!', err)

  db.get('name', (err, value) => {
    if (err) return console.log('Ooops!', err)

    console.log(`name=${value}`)
  })
})
```

## MySQL

**モジュール**: [mysql](https://github.com/felixge/node-mysql/)

### **インストール**

```bash
$ npm install mysql
```

### 例

```js
const mysql = require('mysql')
const connection = mysql.createConnection({
  host: 'localhost',
  user: 'dbuser',
  password: 's3kreee7',
  database: 'my_db'
})

connection.connect()

connection.query('SELECT 1 + 1 AS solution', (err, rows, fields) => {
  if (err) throw err

  console.log('The solution is: ', rows[0].solution)
})

connection.end()
```

## MongoDB

**モジュール**: [mongodb](https://github.com/mongodb/node-mongodb-native)

### **インストール**

```bash
$ npm install mongodb
```

### 例 (v3.\*)

```js
const MongoClient = require('mongodb').MongoClient

MongoClient.connect('mongodb://localhost:27017/animals', (err, db) => {
  if (err) throw err

  db.collection('mammals').find().toArray((err, result) => {
    if (err) throw err

    console.log(result)
  })
})
```

### 例 (v2.\*)

```js
const MongoClient = require('mongodb').MongoClient

MongoClient.connect('mongodb://localhost:27017/animals', (err, client) => {
  if (err) throw err

  const db = client.db('animals')

  db.collection('mammals').find().toArray((err, result) => {
    if (err) throw err

    console.log(result)
  })
})
```

MongoDB 用のオブジェクト・モデル・ドライバーが必要な場合は、[Mongoose](https://github.com/LearnBoost/mongoose) を参照してください。

## Neo4j

データベースを Express アプリケーションに接続できるようにするには、単にデータベースに適切な Node.js ドライバーをアプリケーションにロードするだけですみます。本書では、データベース・システム用の最も一般的な Node.js モジュールを Express アプリケーションに追加して使用する方法について簡単に説明します。

### **インストール**

```bash
$ npm install neo4j-driver
```

### 例

```js
const neo4j = require('neo4j-driver')
const driver = neo4j.driver('neo4j://localhost:7687', neo4j.auth.basic('neo4j', 'letmein'))

const session = driver.session()

session.readTransaction((tx) => {
  return tx.run('MATCH (n) RETURN count(n) AS count')
    .then((res) => {
      console.log(res.records[0].get('count'))
    })
    .catch((error) => {
      console.log(error)
    })
})
```

## Oracle

**モジュール**: [oracledb](https://github.com/oracle/node-oracledb)

### **インストール**

NOTE: [See installation prerequisites](https://github.com/oracle/node-oracledb#-installation).

```bash
$ npm install oracledb
```

### 例

```js
const oracledb = require('oracledb')
const config = {
  user: '<your db user>',
  password: '<your db password>',
  connectString: 'localhost:1521/orcl'
}

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

**モジュール**: [pg-promise](https://github.com/vitaly-t/pg-promise)

### **インストール**

```bash
$ npm install pg-promise
```

### 例

```js
const pgp = require('pg-promise')(/* options */)
const db = pgp('postgres://username:password@host:port/database')

db.one('SELECT $1 AS value', 123)
  .then((data) => {
    console.log('DATA:', data.value)
  })
  .catch((error) => {
    console.log('ERROR:', error)
  })
```

## Redis

**モジュール**: [redis](https://github.com/mranney/node_redis)

### **インストール**

```bash
$ npm install redis
```

### 例

```js
const redis = require('redis')
const client = redis.createClient()

client.on('error', (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', (err, replies) => {
  console.log(`${replies.length} replies:`)

  replies.forEach((reply, i) => {
    console.log(`    ${i}: ${reply}`)
  })

  client.quit()
})
```

## SQL Server

**モジュール**: [tedious](https://github.com/tediousjs/tedious)

### **インストール**

```bash
$ npm install tedious
```

### 例

```js
const Connection = require('tedious').Connection
const Request = require('tedious').Request

const config = {
  server: 'localhost',
  authentication: {
    type: 'default',
    options: {
      userName: 'your_username', // update me
      password: 'your_password' // update me
    }
  }
}

const connection = new Connection(config)

connection.on('connect', (err) => {
  if (err) {
    console.log(err)
  } else {
    executeStatement()
  }
})

function executeStatement () {
  request = new Request("select 123, 'hello world'", (err, rowCount) => {
    if (err) {
      console.log(err)
    } else {
      console.log(`${rowCount} rows`)
    }
    connection.close()
  })

  request.on('row', (columns) => {
    columns.forEach((column) => {
      if (column.value === null) {
        console.log('NULL')
      } else {
        console.log(column.value)
      }
    })
  })

  connection.execSql(request)
}
```

## SQLite

**モジュール**: [sqlite3](https://github.com/mapbox/node-sqlite3)

### **インストール**

```bash
$ npm install sqlite3
```

### 例

```js
const sqlite3 = require('sqlite3').verbose()
const db = new sqlite3.Database(':memory:')

db.serialize(() => {
  db.run('CREATE TABLE lorem (info TEXT)')
  const stmt = db.prepare('INSERT INTO lorem VALUES (?)')

  for (let i = 0; i < 10; i++) {
    stmt.run(`Ipsum ${i}`)
  }

  stmt.finalize()

  db.each('SELECT rowid AS id, info FROM lorem', (err, row) => {
    console.log(`${row.id}: ${row.info}`)
  })
})

db.close()
```

## ElasticSearch

**モジュール**: [elasticsearch](https://github.com/elastic/elasticsearch-js)

### **インストール**

```bash
$ npm install elasticsearch
```

### 例

```js
const elasticsearch = require('elasticsearch')
const client = elasticsearch.Client({
  host: 'localhost:9200'
})

client.search({
  index: 'books',
  type: 'book',
  body: {
    query: {
      multi_match: {
        query: 'express js',
        fields: ['title', 'description']
      }
    }
  }
}).then((response) => {
  const hits = response.hits.hits
}, (error) => {
  console.trace(error.message)
})
```
