新的一天

04. 后端Web基础(基础知识)/springboot-web-01/src/main/java/com/itheima/springbootweb01/SpringbootWeb01Application.java

@@ -3,7 +3,7 @@ package com.itheima.springbootweb01;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 
-@SpringBootApplication
+@SpringBootApplication //
 public class SpringbootWeb01Application {
 
     public static void main(String[] args) {

04. 后端Web基础(基础知识)/springboot-web-01/src/main/java/com/itheima/springbootweb01/controller/UserController.java

@@ -4,6 +4,9 @@ import cn.hutool.core.io.IoUtil;
 import com.itheima.springbootweb01.pojo.User;
 import com.itheima.springbootweb01.service.UserService;
 import com.itheima.springbootweb01.service.lmpl.UserServiceImpl;
+import jakarta.annotation.Resource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 
@@ -28,7 +31,25 @@ public class UserController {
      * 接受请求 相应数据
      */
 
-    private UserService userService = new UserServiceImpl();
+//    @Qualifier("userServiceImpl")
+//    @Autowired
+//    private UserService userService;
+
+    @Resource(name = "userServiceImpl2")
+    private UserService userService;
+    //方式二：构造器注入
+//    private final UserService userService;
+//    @Autowired
+//    public UserController(UserService userService) {
+//        this.userService = userService;
+//    }
+
+    //方式三：setter注入
+//    private UserService userService;
+//    @Autowired
+//    public void setUserService(UserService userService) {
+//        this.userService = userService;
+//    }
 
     //    @RequestMapping("/list")
 //    public List<User> list() throws  Exception{

04. 后端Web基础(基础知识)/springboot-web-01/src/main/java/com/itheima/springbootweb01/dao/impl/UserDaoImpl.java

@@ -2,12 +2,18 @@ package com.itheima.springbootweb01.dao.impl;
 
 import cn.hutool.core.io.IoUtil;
 import com.itheima.springbootweb01.dao.UserDao;
+import org.springframework.stereotype.Component;
+import org.springframework.stereotype.Repository;
+import org.springframework.stereotype.Service;
 
 import java.io.InputStream;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
 
+//@Component // 将当前组件加入到Spring容器中
+//@Repository //将当前组件加入到Spring容器中
+@Service //将当前组件加入到Spring容器中
 public class UserDaoImpl implements UserDao {
     /**
      * 数据层

04. 后端Web基础(基础知识)/springboot-web-01/src/main/java/com/itheima/springbootweb01/service/lmpl/UserServiceImpl.java

@@ -4,16 +4,23 @@ import com.itheima.springbootweb01.dao.UserDao;
 import com.itheima.springbootweb01.dao.impl.UserDaoImpl;
 import com.itheima.springbootweb01.pojo.User;
 import com.itheima.springbootweb01.service.UserService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.AutoConfigureOrder;
+import org.springframework.stereotype.Component;
+import org.springframework.stereotype.Service;
 
 import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
 import java.util.List;
+@Service
 
 public class UserServiceImpl implements UserService {
     /**
      * 业务逻辑层
      */
-    private UserDao userDao = new UserDaoImpl();
+
+    @Autowired // 自动注入
+    private UserDao userDao;
     @Override
     public List<User> findAll() {
         //1.加载Dao层数据

04. 后端Web基础(基础知识)/springboot-web-01/src/main/java/com/itheima/springbootweb01/service/lmpl/UserServiceImpl2.java

@@ -0,0 +1,43 @@
+package com.itheima.springbootweb01.service.lmpl;
+
+import com.itheima.springbootweb01.dao.UserDao;
+import com.itheima.springbootweb01.pojo.User;
+import com.itheima.springbootweb01.service.UserService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Primary;
+import org.springframework.stereotype.Component;
+import org.springframework.stereotype.Service;
+
+import java.time.LocalDateTime;
+import java.time.format.DateTimeFormatter;
+import java.util.List;
+
+@Service
+//@Primary
+
+public class UserServiceImpl2 implements UserService {
+    /**
+     * 业务逻辑层
+     */
+
+    @Autowired // 自动注入
+    private UserDao userDao;
+    @Override
+    public List<User> findAll() {
+        //1.加载Dao层数据
+        List<String> lines = userDao.findAll();
+
+        //2.将用户数据封装成User对象 ->list集合
+        List<User> userList= lines.stream().map(line -> {
+            String[] split = line.split(",");
+            Integer id = Integer.parseInt(split[0]);
+            String username = split[1];
+            String password = split[2];
+            String name = split[3];
+            Integer age = Integer.parseInt(split[4]);
+            LocalDateTime updateTime = LocalDateTime.parse(split[5], DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"));
+            return new User(id+200, username, password, name, age, updateTime);
+        }).toList();
+        return userList;
+    }
+}

05. 后端Web基础(数据库)/MySql01.sql

@@ -0,0 +1,301 @@
+# 查询所有数据库
+show databases ;
+
+#切换数据库
+use db01;
+
+#查询当前使用的数据库
+select database();
+
+#创建数据库
+create database db03;
+
+#删除数据库
+drop database db03;
+
+# -------------------------->表操作<---------------------
+#创建表
+create table user(
+    id int comment 'ID 唯一',
+    username varchar(50) comment '用户名',
+    name varchar(10) comment '姓名',
+    age int comment '年龄',
+    gender char(1) comment '性别'
+)comment '用户表';
+
+#删除表
+drop table user;
+
+#创建约束表
+create table user(
+    id int unsigned primary key auto_increment comment 'ID 唯一', -- 主键约束
+    username varchar(50) not null unique comment '用户名', -- 唯一非空约束
+    name varchar(10) not null comment '姓名', -- 非空约束
+    age tinyint unsigned comment '年龄',
+    gender char(1) default '男' comment '性别'
+)comment '用户表';
+
+
+# 案例：设计员工表 emp
+create table emp(
+    id int unsigned primary key auto_increment comment 'ID 唯一',
+    username varchar(20) not null unique comment '用户名', -- 唯一非空约束
+    password varchar(20) not null default '123456' comment '密码',
+    name varchar(10) not null comment '姓名',
+    gender tinyint unsigned not null default 1 comment '性别: 1男 2女', -- 修改为数值默认值
+    phone char(11) not null comment '手机号',
+    job tinyint unsigned comment '职位: 1班主任 2讲师 3学生主管 4教研主管 5咨询师',
+    salary int unsigned comment '薪资',
+    entry_date date comment '入职时间',
+    image varchar(255) comment '图像',
+    create_time timestamp comment '创建时间',
+    update_time timestamp comment '更新时间'
+)comment '员工表';
+
+
+
+# -------------------------->数据操作<---------------------
+#查询当前所有表
+show tables;
+
+#查看表结构
+describe emp;
+
+#查询建表语句
+show create table emp;
+
+#添加字段 qq varchar(13)
+alter table emp add qq varchar(13) comment 'QQ';
+
+#修改字段 qq varchar(13) -> varchar(15)
+alter table emp modify qq varchar(15) comment 'QQ';
+
+#修改字段名 qq -> qq_num
+alter table emp change qq qq_num varchar(15) comment 'QQ';
+
+#删除字段 qq_num
+alter table emp drop qq_num;
+
+#修改表名
+alter table emp rename to employee;
+
+#删除表
+drop table employee;
+
+
+
+# -------------------------->DML<---------------------
+
+-- DML : 数据操作语言
+-- DML : 插入数据 - insert
+-- 1. 为 emp 表的 username, password, name, gender, phone 字段插入值
+insert into emp(username, password, name, gender, phone) values('songjiang', '12345678', '宋江', 1, '13888888888');
+
+insert into emp(username, password, name, gender, phone) values('songjiang2', '12345678', '宋江', 1, '13888888888');
+
+-- 2. 为 emp 表的 所有字段插入值
+#方式一
+insert  into emp(id, username, password, name, gender, phone, job, salary, entry_date, image, create_time, update_time)
+    values (null, 'linchong', '12345678', '林冲', 1, '13888888882', 1, 6000, '2020-01-01', '1.jpg', now(), now());
+#方式二
+insert into emp values(null, 'likui', '12345678', '李逵', 1, '13888888883', 1, 6000, '2020-01-01', '1.jpg', now(), now());
+-- 3. 批量为 emp 表的 username, password, name, gender, phone  字段插入数据
+insert into emp(username, password, name, gender, phone) values
+    ('lisi', '12345678', '李四', 1, '13888888884'),
+    ('wangwu', '12345678', '王五', 1, '13888888885'),
+    ('zhaoliu', '12345678', '赵六', 1, '13888888886'),
+    ('tianqi', '12345678', '田七', 1, '13888888887');
+
+-- DML : 更新数据 - update
+-- 1. 将 emp 表的ID为1员工 用户名更新为 'zhangsan', 姓名name字段更新为 '张三'
+update emp set username = 'zhangsan', name = '张三' where id = 1;
+
+-- 2. 将 emp 表的所有员工的入职日期更新为 '2010-01-01'
+update emp set entry_date = '2010-01-01';
+
+
+
+-- DML : 删除数据 - delete
+-- 1. 删除 emp 表中 ID为1的员工
+delete from emp where id = 1;
+
+-- 2. 删除 emp 表中的所有员工
+delete from emp;
+
+
+
+-- 准备测试数据
+INSERT INTO emp(id, username, password, name, gender, phone, job, salary, image, entry_date, create_time, update_time)
+VALUES (1,'shinaian','123456','施耐庵',1,'13309090001',4,15000,'1.jpg','2000-01-01','2024-04-11 16:35:33','2024-04-11 16:35:35'),
+     (2,'songjiang','123456','宋江',1,'13309090002',2,8600,'2.jpg','2015-01-01','2024-04-11 16:35:33','2024-04-11 16:35:37'),
+     (3,'lujunyi','123456','卢俊义',1,'13309090003',2,8900,'3.jpg','2008-05-01','2024-04-11 16:35:33','2024-04-11 16:35:39'),
+     (4,'wuyong','123456','吴用',1,'13309090004',2,9200,'4.jpg','2007-01-01','2024-04-11 16:35:33','2024-04-11 16:35:41'),
+     (5,'gongsunsheng','123456','公孙胜',1,'13309090005',2,9500,'5.jpg','2012-12-05','2024-04-11 16:35:33','2024-04-11 16:35:43'),
+     (6,'huosanniang','123456','扈三娘',2,'13309090006',3,6500,'6.jpg','2013-09-05','2024-04-11 16:35:33','2024-04-11 16:35:45'),
+     (7,'chaijin','123456','柴进',1,'13309090007',1,4700,'7.jpg','2005-08-01','2024-04-11 16:35:33','2024-04-11 16:35:47'),
+     (8,'likui','123456','李逵',1,'13309090008',1,4800,'8.jpg','2014-11-09','2024-04-11 16:35:33','2024-04-11 16:35:49'),
+     (9,'wusong','123456','武松',1,'13309090009',1,4900,'9.jpg','2011-03-11','2024-04-11 16:35:33','2024-04-11 16:35:51'),
+     (10,'lichong','123456','林冲',1,'13309090010',1,5000,'10.jpg','2013-09-05','2024-04-11 16:35:33','2024-04-11 16:35:53'),
+     (11,'huyanzhuo','123456','呼延灼',1,'13309090011',2,9700,'11.jpg','2007-02-01','2024-04-11 16:35:33','2024-04-11 16:35:55'),
+     (12,'xiaoliguang','123456','小李广',1,'13309090012',2,10000,'12.jpg','2008-08-18','2024-04-11 16:35:33','2024-04-11 16:35:57'),
+     (13,'yangzhi','123456','杨志',1,'13309090013',1,5300,'13.jpg','2012-11-01','2024-04-11 16:35:33','2024-04-11 16:35:59'),
+     (14,'shijin','123456','史进',1,'13309090014',2,10600,'14.jpg','2002-08-01','2024-04-11 16:35:33','2024-04-11 16:36:01'),
+     (15,'sunerniang','123456','孙二娘',2,'13309090015',2,10900,'15.jpg','2011-05-01','2024-04-11 16:35:33','2024-04-11 16:36:03'),
+     (16,'luzhishen','123456','鲁智深',1,'13309090016',2,9600,'16.jpg','2010-01-01','2024-04-11 16:35:33','2024-04-11 16:36:05'),
+     (17,'liying','12345678','李应',1,'13309090017',1,5800,'17.jpg','2015-03-21','2024-04-11 16:35:33','2024-04-11 16:36:07'),
+     (18,'shiqian','123456','时迁',1,'13309090018',2,10200,'18.jpg','2015-01-01','2024-04-11 16:35:33','2024-04-11 16:36:09'),
+     (19,'gudasao','123456','顾大嫂',2,'13309090019',2,10500,'19.jpg','2008-01-01','2024-04-11 16:35:33','2024-04-11 16:36:11'),
+     (20,'ruanxiaoer','123456','阮小二',1,'13309090020',2,10800,'20.jpg','2018-01-01','2024-04-11 16:35:33','2024-04-11 16:36:13'),
+     (21,'ruanxiaowu','123456','阮小五',1,'13309090021',5,5200,'21.jpg','2015-01-01','2024-04-11 16:35:33','2024-04-11 16:36:15'),
+     (22,'ruanxiaoqi','123456','阮小七',1,'13309090022',5,5500,'22.jpg','2016-01-01','2024-04-11 16:35:33','2024-04-11 16:36:17'),
+     (23,'ruanji','123456','阮籍',1,'13309090023',5,5800,'23.jpg','2012-01-01','2024-04-11 16:35:33','2024-04-11 16:36:19'),
+     (24,'tongwei','123456','童威',1,'13309090024',5,5000,'24.jpg','2006-01-01','2024-04-11 16:35:33','2024-04-11 16:36:21'),
+     (25,'tongmeng','123456','童猛',1,'13309090025',5,4800,'25.jpg','2002-01-01','2024-04-11 16:35:33','2024-04-11 16:36:23'),
+     (26,'yanshun','123456','燕顺',1,'13309090026',5,5400,'26.jpg','2011-01-01','2024-04-11 16:35:33','2024-04-11 16:36:25'),
+     (27,'lijun','123456','李俊',1,'13309090027',5,6600,'27.jpg','2004-01-01','2024-04-11 16:35:33','2024-04-11 16:36:27'),
+     (28,'lizhong','123456','李忠',1,'13309090028',5,5000,'28.jpg','2007-01-01','2024-04-11 16:35:33','2024-04-11 16:36:29'),
+     (29,'songqing','123456','宋清',1,'13309090029',5,5100,'29.jpg','2020-01-01','2024-04-11 16:35:33','2024-04-11 16:36:31'),
+     (30,'liyun','123456','李云',1,'13309090030',NULL,NULL,'30.jpg','2020-03-01','2024-04-11 16:35:33','2024-04-11 16:36:31');
+
+
+
+
+
+
+--  =================== DQL: 基本查询 ======================
+-- 1. 查询指定字段 name,entry_date 并返回
+select name, entry_date from emp;
+
+
+-- 2. 查询返回所有字段
+#方式一：不推荐
+select * from emp;
+#方式二：推荐
+select id, username, password, name, gender, phone, job, salary, image, entry_date, create_time, update_time from emp;
+
+-- 3. 查询所有员工的 name,entry_date, 并起别名(姓名、入职日期)
+select name as 姓名, entry_date as 入职日期 from emp;
+select name as 姓名, emp.entry_date as 入职日期 from emp;
+select name 姓名, emp.entry_date 入职日期 from emp;
+
+-- 4. 查询已有的员工关联了哪几种职位(不要重复) --distinct 去除重复
+select distinct job from emp;
+
+
+--  =================== DQL: 条件查询 ======================
+-- 1. 查询 姓名 为 柴进 的员工
+select * from emp where name = '柴进';
+select * from emp where name = '柴进';
+
+-- 2. 查询 薪资小于等于5000 的员工信息
+select * from emp where salary <= 5000;
+select * from emp where salary <= 5000;
+
+-- 3. 查询 没有分配职位 的员工信息
+select * from emp where job is null;
+
+
+-- 4. 查询 有职位 的员工信息
+select * from emp where job is not null;
+
+
+-- 5. 查询 密码不等于 '123456' 的员工信息
+select * from emp where password != '123456';
+
+
+-- 6. 查询 入职日期 在 '2000-01-01' (包含) 到 '2010-01-01'(包含) 之间的员工信息\
+select * from emp where entry_date >= '2000-01-01' and entry_date <= '2010-01-01';
+
+
+-- 7. 查询 入职时间 在 '2000-01-01' (包含) 到 '2010-01-01'(包含) 之间 且 性别为女 的员工信息
+select * from emp where entry_date >= '2000-01-01' and entry_date <= '2010-01-01' and gender = 2;
+
+-- 8. 查询 职位是 2 (讲师), 3 (学工主管), 4 (教研主管) 的员工信息
+select * from emp where job in (2,3,4);
+select * from emp where job = 2 or job = 3 or job = 4;
+
+
+-- 9. 查询 姓名 为两个字的员工信息
+select * from emp where name like '__';
+
+
+-- 10. 查询 姓 '李' 的员工信息
+select * from emp where name like '李%';
+
+
+-- 11. 查询 姓名中包含 '二' 的员工信息
+select * from emp where name like '%二%';
+
+
+
+--  =================== DQL: 分组查询 ======================
+-- 聚合函数
+-- 所有null不参与计数
+-- 1. 统计该企业员工数量
+-- cont(字段)
+select count(id) from emp;
+
+-- cont(*) 推荐
+select count(*) from emp;
+
+-- cont(常量)
+select count(123) from emp;
+
+-- 2. 统计该企业员工的平均薪资
+select avg(salary) from emp;
+
+
+-- 3. 统计该企业员工的最低薪资
+select min(salary) from emp;
+
+
+-- 4. 统计该企业员工的最高薪资
+select max(salary) from emp;
+
+
+-- 5. 统计该企业每月要给员工发放的薪资总额(薪资之和)
+select sum(salary) from emp;
+
+
+
+
+
+-- 分组
+-- 1. 根据性别分组 , 统计男性和女性员工的数量
+select gender 性别, count(*) 数量 from emp group by gender;
+select gender, count(*) from emp group by gender;
+
+
+-- 2. 先查询入职时间在 '2015-01-01' (包含) 以前的员工 , 并对结果根据职位分组 , 获取员工数量大于等于2的职位
+select job, count(*) from emp where entry_date <= '2015-01-01' group by job having count(*) >= 2;
+
+
+
+--  =================== 排序查询 ======================
+-- 1. 根据入职时间, 对员工进行升序排序
+select * from emp order by entry_date;
+select * from emp order by entry_date asc;
+
+
+-- 2. 根据入职时间, 对员工进行降序排序
+select * from emp order by entry_date desc;
+
+-- 3. 根据 入职时间 对公司的员工进行 升序排序 ， 入职时间相同 , 再按照 更新时间 进行降序排序
+select * from emp order by entry_date asc, update_time desc;
+
+
+
+
+--  =================== 分页查询 ======================
+-- 1. 从起始索引0开始查询员工数据, 每页展示5条记录
+select * from emp limit 0,5;
+
+-- 2. 查询 第1页 员工数据, 每页展示5条记录
+select * from emp limit 0,5;
+
+-- 3. 查询 第2页 员工数据, 每页展示5条记录
+select * from emp limit 5,5;
+
+-- 4. 查询 第3页 员工数据, 每页展示5条记录
+select * from emp limit 10,5;
+

06. 后端Web基础(java操作数据库)/jdbc-demo/.gitignore

@@ -0,0 +1,38 @@
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### IntelliJ IDEA ###
+.idea/modules.xml
+.idea/jarRepositories.xml
+.idea/compiler.xml
+.idea/libraries/
+*.iws
+*.iml
+*.ipr
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store

06. 后端Web基础(java操作数据库)/jdbc-demo/.idea/.gitignore

@@ -0,0 +1,8 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml

06. 后端Web基础(java操作数据库)/jdbc-demo/.idea/encodings.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="Encoding">
+    <file url="file://$PROJECT_DIR$/src/main/java" charset="UTF-8" />
+    <file url="file://$PROJECT_DIR$/src/main/resources" charset="UTF-8" />
+  </component>
+</project>

06. 后端Web基础(java操作数据库)/jdbc-demo/.idea/misc.xml

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ExternalStorageConfigurationManager" enabled="true" />
+  <component name="MavenProjectsManager">
+    <option name="originalFiles">
+      <list>
+        <option value="$PROJECT_DIR$/pom.xml" />
+      </list>
+    </option>
+  </component>
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="corretto-17" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>

06. 后端Web基础(java操作数据库)/jdbc-demo/.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$/../.." vcs="Git" />
+  </component>
+</project>

06. 后端Web基础(java操作数据库)/jdbc-demo/pom.xml

@@ -0,0 +1,44 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>org.itheima</groupId>
+    <artifactId>jdbc-demo</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <maven.compiler.source>17</maven.compiler.source>
+        <maven.compiler.target>17</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <dependencies>
+        <dependency>
+            <groupId>com.mysql</groupId>
+            <artifactId>mysql-connector-j</artifactId>
+            <version>8.0.33</version>
+        </dependency>
+
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <version>5.9.3</version>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <version>1.18.30</version>
+        </dependency>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>RELEASE</version>
+            <scope>compile</scope>
+        </dependency>
+    </dependencies>
+
+</project>

06. 后端Web基础(java操作数据库)/jdbc-demo/src/main/java/com/itheima/pojo/User.java

@@ -0,0 +1,18 @@
+package com.itheima.pojo;
+
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class User {
+    private Integer id;
+    private String username;
+    private String password;
+    private String name;
+    private Integer age;
+
+}

06. 后端Web基础(java操作数据库)/jdbc-demo/src/main/java/org/itheima/JdbcTest.java

@@ -0,0 +1,70 @@
+package org.itheima;
+
+import com.itheima.pojo.User;
+import org.junit.Test;
+
+import java.sql.*;
+
+public class JdbcTest {
+    @Test
+    public void testUpdate() throws Exception {
+        //1.注册驱动
+        Class.forName("com.mysql.cj.jdbc.Driver");
+
+        //2.获取连接
+        String url = "jdbc:mysql://localhost:3306/web01";
+        String username = "root";
+        String password = "123456";
+        Connection connection = DriverManager.getConnection(url, username, password);
+
+        //3.获取数据库操作对象
+        Statement statement = connection.createStatement();
+
+        //4.执行sql语句
+        int i = statement.executeUpdate("update user set age = 25 where id = 1");//DML
+        System.out.println("SQL执行完毕" + i);
+
+        //5.释放资源
+        statement.close();
+        connection.close();
+    }
+
+    @Test
+    public void testSelect() throws Exception {
+        String url = "jdbc:mysql://localhost:3306/web01";
+        String username = "root";
+        String password = "123456";
+
+        Connection conn = null;
+        PreparedStatement stmt = null;
+        ResultSet rs = null; //封装查询返回的结果集
+
+        try {
+            //1.注册驱动
+            Class.forName("com.mysql.cj.jdbc.Driver");
+            //2.获取连接
+            conn = DriverManager.getConnection(url, username, password);
+            //3.执行查询
+            String sql = "select id, username, password, name, age FROM user WHERE username = ? AMD password = ?";
+            stmt = conn.prepareStatement(sql);
+
+            stmt.setString(1, "daqiao");
+            stmt.setString(2, "123456");
+
+            rs = stmt.executeQuery();
+
+            //4.处理结果
+            while (rs.next()) {
+                User user = new User(
+                        rs.getInt("id"),
+                        rs.getString("username"),
+                        rs.getString("password"),
+                        rs.getString("name"),
+                        rs.getInt("age")
+                );
+                System.out.println(user);
+
+            }
+        }
+    }
+}