node.js博客学习二

环境搭建

• 从零开始，不适用框架
• 使用nodemon监测文件变化，自动重启node
• 使用cross-env设置环境变量

初始化路由

blog.js 和 user.js 通过监听HTTP初步实现各api响应

在app.js中引用实现路由拆分

控制层实现具体数据库操作方法

初始用模拟数据而不连接数据库

创建回复模型

class BaseModel {
    constructor(data, message) {
        if (typeof data === 'string') {
            this.message = data
            data = null
            message = null
        }
        if (data) {
            this.data = data
        }
        if (message) {
            this.message = message
        }
    }
}

class SuccessModel extends BaseModel {
    constructor(data, message) {
        super(data, message)
        this.errno = 0
    }
}

class ErrorModel extends BaseModel {
    constructor(data, message) {
        super(data, message)
        this.errno = -1
    }
}

module.exports = {
    SuccessModel,
    ErrorModel
}

MySQL数据库

数据库配置线上和线下

const env = process.env.NODE_ENV  // 环境参数

// 配置
let MYSQL_CONF
let REDIS_CONF

if (env === 'dev') {
    // mysql
    MYSQL_CONF = {
        host: 'localhost',
        user: 'root',
        password: '',
        port: '3306',
        database: 'myblog'
    }
}

if (env === 'production') {
    // mysql
    MYSQL_CONF = {
        host: 'localhost',
        user: 'root',
        password: '',
        port: '3306',
        database: 'myblog'
    }
}

module.exports = {
    MYSQL_CONF
}

连接数据库

• 安装MySQL npm install mysql --save

• 连接并创建公用执行sql语句方法

const mysql = require('mysql')
const { MYSQL_CONF } = require('../conf/db')

// 创建链接对象
const con = mysql.createConnection(MYSQL_CONF)

// 开始链接
con.connect()

// 统一执行 sql 的函数
function exec(sql) {
    const promise = new Promise((resolve, reject) => {
        con.query(sql, (err, result) => {
            if (err) {
                reject(err)
                return
            }
            resolve(result)
        })
    })
    return promise
}

module.exports = {
    exec,
    escape: mysql.escape
}

控制层数据库增删改查方法封装

• blog相关操作

const xss = require('xss')
const { exec } = require('../db/mysql')

const getList = (author, keyword) => {
    let sql = `select * from blogs where 1=1 `
    if (author) {
        sql += `and author='${author}' `
    }
    if (keyword) {
        sql += `and title like '%${keyword}%' `
    }
    sql += `order by createtime desc;`

    // 返回 promise
    return exec(sql)
}

const getDetail = (id) => {
    const sql = `select * from blogs where id='${id}'`
    return exec(sql).then(rows => {
        return rows[0]
    })
}

const newBlog = (blogData = {}) => {
    // blogData 是一个博客对象，包含 title content author 属性
    const title = xss(blogData.title)
    // console.log('title is', title)
    const content = xss(blogData.content)
    const author = blogData.author
    const createTime = Date.now()

    const sql = `
        insert into blogs (title, content, createtime, author)
        values ('${title}', '${content}', ${createTime}, '${author}');
    `

    return exec(sql).then(insertData => {
        // console.log('insertData is ', insertData)
        return {
            id: insertData.insertId
        }
    })
}

const updateBlog = (id, blogData = {}) => {
    // id 就是要更新博客的 id
    // blogData 是一个博客对象，包含 title content 属性

    const title = xss(blogData.title)
    const content = xss(blogData.content)

    const sql = `
        update blogs set title='${title}', content='${content}' where id=${id}
    `

    return exec(sql).then(updateData => {
        // console.log('updateData is ', updateData)
        if (updateData.affectedRows > 0) {
            return true
        }
        return false
    })
}

const delBlog = (id, author) => {
    // id 就是要删除博客的 id
    const sql = `delete from blogs where id='${id}' and author='${author}';`
    return exec(sql).then(delData => {
        // console.log('delData is ', delData)
        if (delData.affectedRows > 0) {
            return true
        }
        return false
    })
}

module.exports = {
    getList,
    getDetail,
    newBlog,
    updateBlog,
    delBlog
}

• user相关操作

const { exec, escape } = require('../db/mysql')
const { genPassword } = require('../utils/cryp')

const login = (username, password) => {
    username = escape(username)
    
    // 生成加密密码
    password = genPassword(password)
    password = escape(password)

    const sql = `
        select username, realname from users where username=${username} and password=${password}
    `
    // console.log('sql is', sql)
    return exec(sql).then(rows => {
        return rows[0] || {}
    })
}

module.exports = {
    login
}