노드가 mysql 데이터베이스에 연결하는 방법에 대한 간략한 설명

(async () => { // 链接数据库 const mysql = require('mysql2/promise'); // npm i mysql2 const cfg = { host: 'localhost', user: 'root', password: ';he%0f_,ljyW', database: 'izengx', } const connection = await mysql.createConnection(cfg); // 创建一个新表tests let ret = await connection.execute(`CREATE TABLE IF NOT EXISTS tests ( id INT NOT NULL AUTO_INCREMENT, message VARCHAR(45) NULL, PRIMARY KEY (id) )`) console.log('create', ret); // 新建数据 ret = await connection.execute(`INSERT INTO tests(message) VALUE(?)`, ['newData']) console.log('新建数据', ret); const [rows, fields] = await connection.execute(` SELECT * FROM tests `) console.log('查询数据', rows); })()

(async () => { // 使用数据库中间件（ORM）：sequelize连接和操作数据库 // 1. 使用Sequelize时，生成的表名会自动加成复数s，如fruit->fruits // 2. 自动生成主键id，自增（缺点是合并新旧数据时，id又从1开始，会有重合） const Sequelize = require('sequelize'); const sequelize = new Sequelize('izengx', 'root', ';he%0f_,ljyW', { host: 'localhost', dialect: 'mysql', operatorsAliases: false, }) const Fruit =sequelize.define('Fruit', { name: {type: Sequelize.STRING(20), allowNull: false,}, price: {type: Sequelize.FLOAT, allowNull: false}, stock: {type: Sequelize.INTEGER, defaultValue: 0} }) // 同步数据库 let ret = await Fruit.sync(); // 增加一条数据 ret = await Fruit.create({ name: 'apple', price: 3.5 }) // 更新数据 await Fruit.update({ price: 4, }, { where: { name: 'banana', } }) // 查询 ret = await Fruit.findAll(); // 查询指定范围的数据 const Op = Sequelize.Op; opRet = await Fruit.findAll({ where: { price: { [Op.gt]: 3, [Op.lt]: 5, } } }) console.log('search: '+ JSON.stringify(opRet)); })()