react 项目--博客系统 (五)

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接着上文，创建完数据库后，需要一个包进行服务端与数据库的连接 ( 称为 Server 通过 ORM 连接数据库)；

我们在服务器的终端输入 npm i sequelize mysql2 安装两个包用来服务端与数据库建立连接；

在客户端的 app.js 中将新增加的包引入并且将其实例化；

const {Sequelize}=require('sequelize')

const sequelize=new Sequelize(process.env.DB_NAME,process.env.DB_USERNAME,process.env.DB_PASSWORD,{
    dialect:process.env.DB_DIALECT,
    host:process.env.DB_HOST,
    port:process.env.DB_PORT,
    logging:false,

})

并在 .env 中配置相应的数据；

# mysql
DB_NAME = gt_v1
DB_USERNAME = root
DB_PASSWORD = 123456
DB_DIALECT = mysql
DB_HOST = localhost
DB_PORT = 3306

在 app.js 文件中插入一段调试代码，用来查看数据库与客户端是否联通；

const dbConnection = async () => {
    try {
        await sequelize.authenticate();
        console.log('mysql Connection successful !!! ');
    } catch (error) {
        console.error('Unable to connect to the database:', error);
    }

}
dbConnection()

最后在终端启动服务，出现 mysql Connection successful !!! 说明数据库与服务器连接成功；

app.js 中代码：

require('dotenv').config({ path: '.env' })

const express = require('express')
const { Sequelize } = require('sequelize')

const sequelize = new Sequelize(process.env.DB_NAME, process.env.DB_USERNAME, process.env.DB_PASSWORD, {
    dialect: process.env.DB_DIALECT,
    host: process.env.DB_HOST,
    port: process.env.DB_PORT,
    logging: false

})

const dbConnection = async () => {
    try {
        await sequelize.authenticate();
        console.log('mysql Connection successful !!! ');
    } catch (error) {
        console.error('Unable to connect to the database:', error);
    }

}
dbConnection()

const app = express()

const PORT = process.env.PORT || 8080

app.listen(PORT, () => {
    console.log(`running http://localhost:${PORT}`);
})

.env 中代码：

# server
HOST = localhost
PORT = 8000

# mysql
DB_NAME = gt_v1
DB_USERNAME = root
DB_PASSWORD = 123456
DB_DIALECT = mysql
DB_HOST = localhost
DB_PORT = 3306

未完待续......