NodeJS（express）连接、封装操作MySQL
最近要开发一个全栈项目。第一次上车，小本本记录一下，以免忘记。
1.目录结构
先来看一下项目目录：
web文件夹：是放一些前端的代码；
node_serve：服务端的一些文件；
– server.js：服务端入口文件；
– db : 有关数据库的一些文件；
---- db.js：数据库增、删、改、查api的封装；
---- dbconfig.js: 数据库的配置
---- json.js: 消息请求响应(暂时放在这里先)；
---- sql.js: 对操作数据库不同表的sql语句的封装
数据库目录：
2.入口文件：
/**
* Created by Walker on 2020/04/30.
* 服务器入口文件
* 热加载 supervisor server.js
*/
const express = require("express");
const app = express();
var url = require("url");
var bodyParser = require("body-parser"); //格式化请求消息的中间件
const db = require("./db/db.js");
app.use(bodyParser.urlencoded({
extended: false }));
//设置允许跨域的域名，*代表允许任意域名跨域
app.all("*", function (req, res, next) {
res.header("Access-Control-Allow-Origin", "*"); //允许的header类型
res.header("Access-Control-Allow-Headers", "Content-type"); //跨域允许的请求方式
res.header(
"Access-Control-Allow-Methods",
"PUT,POST,GET,DELETE,OPTIONS,PATCH"
); //可选，用来指定本次预检请求的有效期，单位为秒。在此期间，不用发出另一条预检请求。
res.header("Access-Control-Max-Age", 1728000); //预请求缓存20天
next();
});
//下面是一些供前端使用的测试接口；
//get和post方法，对从前端接收的请求data的处理会有区别，可以注意一下；
app.get("/", (req, res) => res.send("Hello World!"));
app.get("/index_getdata", (req, res) => {
var name = url.parse(req.url, true).query;
console.log(name);
});
app.post("/add", (req, res, next) => {
let body = req.body;
console.log("dbAdd", req.body);
let sqlParam = {
id: body.uuid,
name: body.name,
};
console.log("dbAdd", sqlParam);
db.dbAdd("teacher", sqlParam, res, next);
});
app.post("/delete_data", (req, res, next) => {
let body = req.body;
console.log("delet", req.body);
let sqlParam = {
id: body.uuid,
};
console.log("delet", sqlParam);
db.dbDelete("teacher", sqlParam, res, next);
});
app.post("/update_data", (req, res, next) => {
let body = req.body;
console.log("update", req.body);
let sqlParam = {
name: body.name,
id: body.uuid,
};
console.log("update", sqlParam);
db.dbUpdate("teacher", sqlParam, res, next);
});
app.post("/queryById_data", (req, res, next) => {
let body = req.body;
console.log("queryById_data", req.body);
let sqlParam = {
id: body.uuid,
};
console.log("queryById_data", sqlParam);
db.dbQueryById("teacher", sqlParam, res, next);
});
app.get("/queryAll_data", (req, res, next) => {
db.dbQueryAll("teacher", "", res, next);
});
app.listen(3000, () => console.log("Example app listening on port 3000!"));
3.mysql连接的配置
/**
* Created by Walker on 2020/05/06.
* 数据库的配置
*/
var mysqlConfig = {
host: "localhost",
user: "root",
password: "123456",
port: "3306",
database: "sqltest",
};
module.exports = mysqlConfig
4.数据库连接、API的封装
/**
* Created by Walker on 2020/05/06.
* 数据库增、删、改、查封装
*/
//mysql连接池配置文件
const mysql = require("mysql");
const $dbConfig = require("./dbConfig"); //注意改成自己项目中mysql配置文件的路径
const sql = require("./sql.js"); //sql语句封装
const pool = mysql.createPool($dbConfig); // 使用连接池，避免开太多的线程，提升性能
const json = require("./json");
/**
* @description 新增一条数据
* @param {str} table 数据库表的名称
* @param {obj} req 插入的数据
* @param {obj} res 接口函数中的res对象
* @param {obj} next 接口函数中的next对象
*/
let dbAdd = (table, req, res, next) => {
pool.getConnection((err, connection) => {
let paramValue = paramList(req);
connection.query(sql[table].insert, [...paramValue], (err, result) => {
if (result) {
result = "add";
}
// 以json形式，把操作结果返回给前台页面
json(res, result, err);
// 释放连接
connection.release();
});
});
};
/**
*@description 删除一条数据
@param 同abAdd
*/
let dbDelete = (table, req, res, next) => {
let paramValue = paramList(req);
pool.getConnection((err, connection) => {
connection.query(sql[table].delete, [...paramValue], (err, result) => {
if (result.affectedRows > 0) {
result = "delete";
} else {
result = undefined;
}
json(res, result, err);
connection.release();
});
});
};
/**
*@description 修改一条数据
@param 同abAdd
*/
let dbUpdate = (table, req, res, next) => {
let paramValue = paramList(req);
pool.getConnection((err, connection) => {
connection.query(sql[table].update, [...paramValue], (err, result) => {
console.log(result)
if (result.affectedRows > 0) {
result = "update";
} else {
result = undefined;
}
json(res, result, err);
connection.release();
});
});
};
/**
*@description 查找一条数据
@param 同abAdd
*/
let dbQueryById = (table, req, res, next) => {
let paramValue = paramList(req);
pool.getConnection((err, connection) => {
connection.query(sql[table].queryById, [...paramValue], (err, result) => {
if (result != "") {
var _result = result;
result = {
result: "select",
data: _result,
};
} else {
result = undefined;
}
json(res, result, err);
connection.release();
});
});
};
/**
*@description 查找全部数据
@param 同abAdd
*/
let dbQueryAll = (table, req, res, next) => {
pool.getConnection((err, connection) => {
connection.query(sql[table].queryAll, (err, result) => {
if (result != "") {
var _result = result;
result = {
result: "selectall",
data: _result,
};
} else {
result = undefined;
}
json(res, result, err);
connection.release();
});
});
};
/**
* @description 遍历数据的值
* @param {obj} obj 包含参数的对象
* */
let paramList = (obj) => {
let paramArr = [];
for (let key in obj) {
if (obj[key]) {
paramArr.push(obj[key]);
}
}
return paramArr;
};
module.exports = {
dbAdd,
dbDelete,
dbUpdate,
dbQueryById,
dbQueryAll,
};
5.SQL语句的封装
/**
* Created by Walker on 2020/05/06.
* 对操作不同表，sql语句的封装
*/
let test = {
insert: "INSERT INTO test(id, name, age) VALUES(?,?,?)",
update: "UPDATE test SET name=?, age=? WHERE id=?",
delete: "DELETE FROM test WHERE id=?",
queryById: "SELECT * FROM test WHERE id=?",
queryAll: "SELECT * FROM test",
};
let teacher = {
insert: "INSERT INTO teacher(id, name) VALUES(?,?)",
update: "UPDATE teacher SET name=? WHERE id=?",
delete: "DELETE FROM teacher WHERE id=?",
queryById: "SELECT * FROM teacher WHERE id=?",
queryAll: "SELECT * FROM teacher",
};
module.exports = {
teacher,
test,
};
6.封装接送模块
/**
* Created by Walker on 2020/05/06.
* 消息请求响应
*/
//封装接送模块
var json = function (res, result, err) {
if (typeof result === "undefined") {
res.json({
code: "300",
msg: "操作失败:" + err,
});
} else if (result === "add") {
res.json({
code: "200",
msg: "添加成功",
});
} else if (result === "delete") {
res.json({
code: "200",
msg: "删除成功",
});
} else if (result === "update") {
res.json({
code: "200",
msg: "更改成功",
});
} else if (result.result != "undefined" && result.result === "select") {
res.json({
code: "200",
msg: "查找成功",
data: result.data,
});
} else if (result.result != "undefined" && result.result === "selectall") {
res.json({
code: "200",
msg: "全部查找成功",
data: result.data,
});
} else {
res.json(result);
}
};
module.exports = json;
ps: Demo正是初始阶段，还望多多指正或者其他建议，感激。
参考到的Blog:
express+mysql实现简单的增删改查