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How to add and query database data in nodejs? The following article will show you how to implement data addition and query functions in the database based on node.js. I hope it will be helpful to you!
Ideas
Create project serverAPI
Initialize project folder
npm init --y
npm i express mysql
restfulf style
Use Postman software to test
[Recommended learning: "nodejs Tutorial"】
Project structure chart
##Implementation
sql.jsThe file code is as follows:
// 1. 加载msyql
var mysql = require('mysql');
// 2. 创建连接
var connection = mysql.createConnection({
host : 'localhost', // 你要连接的数据库服务器的地址
port : 3306,// 端口号
user : 'root', // 连接数据库服务器需要的用户名
password : 'root', // 连接数据库服务器需要的密码
database : 'yanyan' //你要连接的数据库的名字
});
// 3. 连接数据库
connection.connect((err) => {
// 如果有错误对象，表示连接失败
if (err) return console.log('数据库连接失败')
// 没有错误对象提示连接成功
console.log('mysql数据库连接成功')
});
module.exports = connection
server.jsFile reference Code
const express = require("express");
const app = express();
const connection = require("./utils/sql");
app.use(express.urlencoded());
// 添加数据接口
app.post("/api/student", (req, res) => {
console.log(req.body);
// 接收普通键值对参数
const { name, sex, age } = req.body;
// 添加到数据库中
const sql = `insert into Students(name,sex,age) value('${name}','${sex}',${age})`;
//console.log("要执行的sql", sql);
// result 接受的数据
connection.query(sql, (err, result) => {
if (err) {
console.log(err);
res.json({ msg: "添加失败", code: 0 });
} else {
console.log(result);
res.json({ msg: "添加成功", code: 1 });
}
});
});
// 获取数据接口
app.get("/api/student", (req, res) => {
const sql = `select * from Students `;
connection.query(sql, (err, result) => {
if (err) {
console.log(err);
res.json({ msg: "获取失败", code: 0 });
} else {
console.log(result);
res.json({ msg: "获取成功", code: 0, data: result });
}
});
});
app.listen(3000, () => {
console.log("接口服务器启动，端口号为3000");
});
Run result
Ideas
npm init --y
npm i express mysql
Implementation
##sql.jsfile<pre class="brush:js;toolbar:false;">// 1. 加载mysql
var mysql = require("./node_modules/mysql");
// 2. 创建连接
var connection = mysql.createConnection({
host: "localhost", // 你要连接的数据库服务器的地址
port: 3306, // 端口号
user: "root", // 连接数据库服务器需要的用户名
password: "root", // 连接数据库服务器需要的密码
database: "yanyan", //你要连接的数据库的名字
});
// 3. 连接数据库
connection.connect((err) => {
// 如果有错误对象，表示连接失败
if (err) return console.log("数据库连接失败");
// 没有错误对象提示连接成功
console.log("mysql数据库连接成功");
});
module.exports = connection;</pre>
file <pre class="brush:js;toolbar:false;">const connection = require("./sql");
const express = require("./node_modules/express");
const router = express.Router();
router.use(express.urlencoded());
//获取数据接口
router.get("/api/student", (req, res) => {
const sql = `select * from Students`;
connection.query(sql, (err, result) => {
if (err) {
console.log(err);
res.json({ msg: "获取失败", code: 0 });
} else {
console.log(result);
res.json({ msg: "获取成功", code: 0, data: result });
}
});
});
module.exports = router;</pre>
File<pre class="brush:js;toolbar:false;">const connection = require("./sql");
const express = require("./node_modules/express");
const router = express.Router();
router.use(express.urlencoded());
// 添加数据接口
router.post("/api/student", (req, res) => {
//console.log(req.body);
// 接收普通键值对参数
const { name, sex, age } = req.body;
// 添加到数据库中
const sql = `insert into Students(name,sex,age) values(&#39;${name}&#39;,&#39;${sex}&#39;,${age})`;
//console.log("要执行的sql", sql);
// result 接受的数据
connection.query(sql, (err, data) => {
if (err) {
console.log(err);
res.json({ msg: "添加失败", code: 0 });
} else {
console.log(data);
res.json({ msg: "添加成功", code: 1 });
}
});
});
module.exports = router;</pre>
File<pre class="brush:js;toolbar:false;">const get = require("./utils/get");
const post = require("./utils/post");
const express = require("./node_modules/express");
const app = express();
app.use("/utils/get", get);
app.use("/utils/post", post);
app.listen(3000, () => {
console.log("接口服务器启动，端口号为3000");
});</pre>Original address: https://juejin.cn/post/7008779311666692126
! !Author: Not cowardly
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