MySQL Node.js
用 mysql2 在 Node.js 里连接、查询、防注入。
Key Pointsmysql2 支持 Promise 与连接池，参数化查询天然防注入。
连接与查询
JavaScript
const mysql = require('mysql2/promise');
const pool = mysql.createPool({
host: '127.0.0.1', user: 'app', password: process.env.DB_PASS,
database: 'shop', waitForConnections: true, connectionLimit: 10
});
async function listUsers() {
const [rows] = await pool.query('SELECT id, username FROM users WHERE age > ?', [25]);
return rows;
}Output
[
{ id: 1, username: 'alice' },
{ id: 2, username: 'bob' }
]事务
JavaScript
const conn = await pool.getConnection();
try {
await conn.beginTransaction();
await conn.query('UPDATE accounts SET balance = balance - ? WHERE id = ?', [100, 1]);
await conn.query('UPDATE accounts SET balance = balance + ? WHERE id = ?', [100, 2]);
await conn.commit();
} catch (e) {
await conn.rollback();
throw e;
} finally {
conn.release();
}In production use a connection pool, not a new connection per call; read credentials from env vars. ORMs (Sequelize/Prisma/TypeORM) wrap mysql2.
连接与查询
JavaScript
const mysql = require('mysql2/promise');
const pool = mysql.createPool({
host: '127.0.0.1', user: 'app', password: process.env.DB_PASS,
database: 'shop', waitForConnections: true, connectionLimit: 10
});
async function listUsers() {
const [rows] = await pool.query('SELECT id, username FROM users WHERE age > ?', [25]);
return rows;
}Output
[
{ id: 1, username: 'alice' },
{ id: 2, username: 'bob' }
]事务
JavaScript
const conn = await pool.getConnection();
try {
await conn.beginTransaction();
await conn.query('UPDATE accounts SET balance = balance - ? WHERE id = ?', [100, 1]);
await conn.query('UPDATE accounts SET balance = balance + ? WHERE id = ?', [100, 2]);
await conn.commit();
} catch (e) {
await conn.rollback();
throw e;
} finally {
conn.release();
}生产环境用连接池而非每次新建连接；凭据从环境变量读取，别写死在代码里。ORM 可选 Sequelize / Prisma / TypeORM，它们底层也用 mysql2。