net start mysql

insert into 表名(字段名1，字段名2,....)  values (值1，值2，....)

insert into stu (sex, weight, name) values ("男", 60, "龐凱")

delete  from 表名  where 刪除條件復(fù)制代碼

-- 刪除id為14的同學(xué)delete from stu where id=14-- 刪除的時(shí)候，不加條件，將刪除stu表中的全部記錄delete from stu

update 表名 set 字段1=值1, 字段2=值2,...  where 修改條件

- 要修改的值使用鍵值對(duì)來(lái)表示 - 多個(gè)字段用,分隔- 不指定條件，將修改當(dāng)前表中全部的記錄

-- 修改id為1的同學(xué)的年齡為53update stu set age=53 where id = 1-- 修改id為1的同學(xué)的年齡為35，身高為160update stu set age=35,height=160 where id = 1-- 如果修改的時(shí)候，不加條件，則會(huì)修改全部的數(shù)據(jù)update stu set weight = 60

SELECT  字段名1, 字段名2, .....  FROM 表名  WHERE <條件表達(dá)式>

# 查詢(xún)部分字段SELECT id,name,age FROM stu# 查詢(xún)所有字段SELECT * FROM stu# 帶條件的查詢(xún)SELECT * FROM 表名 WHERE 條件1 and 條件2

-- 查詢(xún)所有的學(xué)生select * from stu-- 查詢(xún)所有學(xué)生的id，name，heightselect id,name,height from stu-- 帶條件的查詢(xún)select * from stu where 條件-- 查詢(xún)所有的男同學(xué)select * from stu where sex="男"-- 查詢(xún)id為2的男同學(xué)select * from stu where id=2-- 查詢(xún)年齡大于50的同學(xué)select * from stu where age > 50-- 查詢(xún)年齡大于50歲的男同學(xué)select * from stu where age>50 and sex="男"-- 查詢(xún)年齡在30~60之間的同學(xué)，包括30和60select * from stu where age>=30 and age<=60select * from stu where age between 30 and 60

# 安裝npm i mysql

var mysql = require("mysql");var connection = mysql.createConnection({  host     : "localhost",   // 你要連接的數(shù)據(jù)庫(kù)服務(wù)器的地址  port     : 3306,// 端口號(hào)  user     : "root",        // 連接數(shù)據(jù)庫(kù)服務(wù)器需要的用戶(hù)名  password : "root",        // 連接數(shù)據(jù)庫(kù)服務(wù)器需要的密碼  database : "gz61"      //你要連接的數(shù)據(jù)庫(kù)的名字});connection.connect((err) => {  // 如果有錯(cuò)誤對(duì)象，表示連接失敗  if (err) return console.log("數(shù)據(jù)庫(kù)連接失敗")  // 沒(méi)有錯(cuò)誤對(duì)象提示連接成功  console.log("mysql數(shù)據(jù)庫(kù)連接成功")});

// 1. 加載mysqlconst mysql = require("mysql");// 2. 創(chuàng)建連接對(duì)象const conn = mysql.createConnection({    // 對(duì)象的屬性名字不能改變    host: "localhost",    port: 3306,    user: "root",    password: "root",    database: "gz61"});// 3. 連接到MySQL服務(wù)器connection.connect((err) => {  // 如果有錯(cuò)誤對(duì)象，表示連接失敗  if (err) return console.log("數(shù)據(jù)庫(kù)連接失敗")  // 沒(méi)有錯(cuò)誤對(duì)象提示連接成功  console.log("mysql數(shù)據(jù)庫(kù)連接成功")});// 4. 執(zhí)行SQL語(yǔ)句let sql = "select id,name,age from stu";connection.query(sql, (err, result, fields) => {    if (err) throw err; // throw err 相當(dāng)于 return console.log(err);    console.log(result); // result就是查詢(xún)結(jié)果});

// 1. 加載mysqlconst mysql = require("mysql");// 2. 創(chuàng)建連接對(duì)象const conn = mysql.createConnection({    // 對(duì)象的屬性名字不能改變    host: "localhost",    port: 3306,    user: "root",    password: "root",    database: "gz61"});// 3. 連接到MySQL服務(wù)器connection.connect((err) => {  // 如果有錯(cuò)誤對(duì)象，表示連接失敗  if (err) return console.log("數(shù)據(jù)庫(kù)連接失敗")  // 沒(méi)有錯(cuò)誤對(duì)象提示連接成功  console.log("mysql數(shù)據(jù)庫(kù)連接成功")});let sql = "insert into users (name,password) values("小王","snv")"connection.query(sql, (err, result) => {    if (result.affectedRows > 0) {        console.log("添加成功，新數(shù)據(jù)的id為：" + result.insertId);    } else {        console.log("添加失敗");    }});

// 1. 加載mysqlconst mysql = require("mysql");// 2. 創(chuàng)建連接對(duì)象const conn = mysql.createConnection({    // 對(duì)象的屬性名字不能改變    host: "localhost",    port: 3306,    user: "root",    password: "root",    database: "gz61"});// 3. 連接到MySQL服務(wù)器connection.connect((err) => {  // 如果有錯(cuò)誤對(duì)象，表示連接失敗  if (err) return console.log("數(shù)據(jù)庫(kù)連接失敗")  // 沒(méi)有錯(cuò)誤對(duì)象提示連接成功  console.log("mysql數(shù)據(jù)庫(kù)連接成功")});// 更新// update stu set 字段=值,字段=值 where id=11let sql = "update users set password="123" where name="小王"";conn.query(sql, (err, result) => {    if (err) throw err;    if (result.affectedRows > 0) {        console.log("修改成功");    } else {        console.log("修改失敗");    }})

// 1. 加載mysqlconst mysql = require("mysql");// 2. 創(chuàng)建連接對(duì)象const conn = mysql.createConnection({    // 對(duì)象的屬性名字不能改變    host: "localhost",    port: 3306,    user: "root",    password: "root",    database: "gz61"});// 3. 連接到MySQL服務(wù)器connection.connect((err) => {  // 如果有錯(cuò)誤對(duì)象，表示連接失敗  if (err) return console.log("數(shù)據(jù)庫(kù)連接失敗")  // 沒(méi)有錯(cuò)誤對(duì)象提示連接成功  console.log("mysql數(shù)據(jù)庫(kù)連接成功")});// 刪除let sql = "delete from stu where id=1";connection.query(sql,(err, result) => {    if (err) throw err;    if (result.affectedRows > 0) {        console.log("刪除成功");    } else {        console.log("刪除失敗");    }});

# 目標(biāo)：把id=16的軟刪除掉update stu set isDelete=1 where id=16

// 由于四項(xiàng)（insert,delete,update,select）操作只是sql語(yǔ)句不同// 1. 加載mysqlconst mysql = require("mysql");// 2. 創(chuàng)建連接對(duì)象const conn = mysql.createConnection({    // 對(duì)象的屬性名字不能改變    host: "localhost",    port: 3306,    user: "root",    password: "root",    database: "gz61"});// 3. 連接到MySQL服務(wù)器connection.connect((err) => {  // 如果有錯(cuò)誤對(duì)象，表示連接失敗  if (err) return console.log("數(shù)據(jù)庫(kù)連接失敗")  // 沒(méi)有錯(cuò)誤對(duì)象提示連接成功  console.log("mysql數(shù)據(jù)庫(kù)連接成功")});module.exports = connection

const conn = require("./sql");conn.query("select * from users where username="小美1" and userpassword="666"", (err, data) => {  console.log(err);  console.log(data);  if (data.length > 0) {    console.log("用戶(hù)名密碼Ok");  } else {    console.log("用戶(hù)名密碼error");  }});