本篇内容介绍了“node如何封装mysql处理语句”的有关知识，在实际案例的操作过程中，不少人都会遇到这样的困境，接下来就让小编带领大家学习一下如何处理这些情况吧！希望大家仔细阅读，能够学有所成！
一.所需包
npm i mysql -S
npm i express -S二.MySql连接文件
const mysql = require('mysql')function createConnection() {
const connection = mysql.createConnection({
host: '', //地址
user: '', //用户名
password: '', //密码
port: '', //端口
database: '' //数据库名
});
return connection;}module.exports.createConnection = createConnection;三.封装文件
引入MySQL连接相关文件，进行连接数据库操作
const mysql = require('../mysql/mysql')let connection = null;connection = mysql.createConnection();/**
* 错误消息
*/let bad_msg = {
code: 500,
msg: '内部错误！'}/**
* 成功消息
*/let success_msg = {
code: 200,
msg: '操作成功'}const connections = {
/**
* 查询方法
* @param {*} table 表名
* @param {*} condition 条件
* @param {*} params 参数
* @param {*} search 查询条件
* @returns
*/
find(table, condition, params, search = '*') {
return new Promise((resolve, reject) => {
let sql = `SELECT ${search} FROM ${table} WHERE ${condition}`
connection.query(sql, params, (err, result) => {
if (err) {
reject(bad_msg)
} else {
let _ = JSON.parse(JSON.stringify(success_msg))
_.data = result resolve(_)
}
})
})
},
/**
* 插入方法
* @param {*} table 表名
* @param {*} condition 条件
* @param {*} params 参数
* @returns
*/
insert(table, condition, params) {
return new Promise((resolve, reject) => {
const str = "?"
let _ = str.repeat((condition.split(',')).length)
let val = (Array.from(_)).toString()
let sql = `INSERT INTO ${table}(${condition}) VALUES(${val})`
connection.query(sql, params, (err, result) => {
if (err) {
reject(bad_msg)
} else {
resolve(success_msg)
}
})
})
},
/**
* 更新方法
* @param {*} table 表名
* @param {*} val 值
* @param {*} condition 条件
* @param {*} params 参数
* @returns
*/
update(table, val, condition, params) {
return new Promise((resolve, reject) => {
let sql = `UPDATE ${table} SET ${val} WHERE ${condition}`
connection.query(sql, params, (err, result) => {
if (err) {
reject(bad_msg)
} else {
resolve(success_msg)
}
})
})
},
/**
* 删除方法
* @param {*} table 表名
* @param {*} condition 条件
* @param {*} params 参数
* @returns
*/
del(table, condition, params) {
return new Promise((resolve, reject) => {
let sql = `DELETE FROM ${table} WHERE ${condition}`
connection.query(sql, params, (err, result) => {
if (err) {
reject(bad_msg)
} else {
resolve(success_msg)
}
})
})
},}module.exports = connections四.使用
我们使用登录注册来进行演示：
const express = require('express')const router = express.Router()const connections = require('../../static/connection')// token生成插件模块const jwt = require('jsonwebtoken');// Token签名var secret = ''const CreatId = require('../../static/ranId')router.post('/user/details', (req, res) => {
connections.find('user_table', `ID=?`,req.user.ID).then(resp => {
res.send(resp)
})})router.post('/api/login', (req, res) => {
connections.find('user_table', 'user=?', req.body.user).then(resp => {
let {data} = resp if (data.length !== 0) {
for (let i = 0; i < data.length; i++) {
// 邮箱或者密码不正确的时候
if (req.body.user !== data[i].user || req.body.pwd !== data[i].pwd) {
res.send({
code: 202,
msg: '用户名或密码有误!'
})
} else {
// 邮箱和密码输入正确
if (req.body.user === data[i].user && req.body.pwd === data[i].pwd) {
// 传输的token内容
let token = jwt.sign({ ID: data[i].ID }, secret, { expiresIn: '72H' });
// 返回结果
res.send({
code: 200,
msg: '操作成功！',
token: 'Bearer ' + token,
})
}
}
}
} else {
res.send({
code: 400,
msg: '账号不存在请注册!'
})
}
}).catch(e => {
res.send(e)
})})router.post('/api/register', (req, res) => {
connections.find('user_table', 'user=?', req.body.user).then(resp => {
if (resp.data.length > 0) {
res.send({
code: 202,
msg: '该用户已经存在！'
})
} else {
let _ = req.body let id = CreatId(3) + CreatId(3)
connections.insert('user_table', 'ID,user,pwd,avatarUrl,location,RegisterTime,isAdmin,isDel', [id, _.user, _.pwd, '/static/userimg/user.webp', _.location, Date.now(), 0, 0]).then(resps => {
// 传输的token内容
let token = jwt.sign({ ID: id }, secret, { expiresIn: '72H' });
// 返回结果
res.send({
code: 200,
msg: '操作成功！',
token: 'Bearer ' + token,
})
})
}
})})module.exports = router