Java 连接MySql数据库配置

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Java 连接MySql数据库配置

用navicat连接MySql

1.点击连接，选择Mysql

2.输入连接名称，密码，安装Mysql时输入的密码，本人默认123456，好记

3.点击测试连接

出现上面这种情况是Mysql服务没有开启

解决方案：

任务管理器 ------服务------找到mysql服务----右键开始

 启动服务之后，打开我们的navicat，再次测试连接，点击确定

 

 打开本地，新建数据库test1，新建一张表

创建表语句：

/*  Navicat Premium Data Transfer

 Source Server         : 本地  Source Server Type    : MySQL  Source Server Version : 50525  Source Host           : localhost:3306  Source Schema         : test1

 Target Server Type    : MySQL  Target Server Version : 50525  File Encoding         : 65001

 Date: 24/04/2022 10:49:21 */

SET NAMES utf8mb4; SET FOREIGN_KEY_CHECKS = 0;

-- ---------------------------- -- Table structure for people -- ---------------------------- DROP TABLE IF EXISTS `people`; CREATE TABLE `people`  (   `id` bigint(20) NOT NULL COMMENT 'id',   `name` varchar(20) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '姓名',   `age` int(20) NULL DEFAULT NULL COMMENT '年龄',   `address` varchar(20) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '地址',   PRIMARY KEY (`id`) USING BTREE ) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Compact;

-- ---------------------------- -- Records of people -- ---------------------------- INSERT INTO `people` VALUES (1, '张三', 20, '上海'); INSERT INTO `people` VALUES (2, '李四', 25, '北京'); INSERT INTO `people` VALUES (3, '王五', 30, '重庆');

SET FOREIGN_KEY_CHECKS = 1;  

数据库就准好了，接下来创建项目，连接数据库获取数据

创建Java项目

引入依赖：

<dependencies> <!-- springmvc的场景启动器 --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> <version>2.6.5</version> </dependency> <!-- 添加lombok的依赖 --> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <version>1.18.8</version> </dependency> <!-- MySQL驱动包 --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.28</version> </dependency> <!-- Mybatis的场景启动器 --> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>2.2.2</version> </dependency> <!-- 单元测试场景启动器 --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <version>2.6.5</version> </dependency> </dependencies>

application.yml配置 server: #端口号 port: 9527 spring: #数据库配置 datasource: driver-class-name: com.mysql.cj.jdbc.Driver url: jdbc:mysql://localhost:3306/test1?useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=convertToNull&useSSL=true&serverTimezone=GMT%2B8 username: root password: 123456 # MyBatis配置 mybatis: mapper-locations: com/thk/mapper/*Mapper.xml 启动类： @SpringBootApplication public class app { public static void main(String[] args) { SpringApplication.run(app.class,args); System.out.println("启动成功！！！"); } }

实体类： package com.thk.domain; public class People { /** * id */ private Long id; /** * 姓名 */ private String name; /** * 年龄 */ private Integer age; /** * 地址 */ private String address; public Long getId() { return id; } public void setId(Long id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } @Override public String toString() { return "People{" + "id=" + id + ", name='" + name + '\\'' + ", age=" + age + ", address='" + address + '\\'' + '}'; } }

Controller： @RestController public class PeopleController { @Autowired private IPeopleService peopleService; /** * 查询全部用户 * @param people * @return */ @GetMapping("/selectAll") public List<People> selectAll( People people) { return peopleService.selectAll(people); } }

service接口 public interface IPeopleService { /** * 查询全部用户 * @param people * @return */ List<People> selectAll(People people); }

service实现类：

@Service public class PeopleImpl implements IPeopleService { @Autowired private PeopleMapper peopleMapper; /** * 查询全部用户 * @param people * @return */ public List<People> selectAll(People people) { return peopleMapper.selectAll(people); } }

mapper接口 @Mapper public interface PeopleMapper { /** * 查询全部用户 * @param people * @return */ List<People> selectAll(People people); }

mapperxml

      

<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE mapper PUBLIC "-//mybatis//DTD Mapper 3.0//EN" "mybatis/dtd/mybatis-3-mapper.dtd" > <mapper namespace="com.thk.mapper.PeopleMapper"> <select id="selectAll" resultType="com.thk.domain.People"> SELECT * FROM people </select> </mapper>

启动项目：、

测试：

浏览器输入：localhost:9527/selectAll

浏览器数据：

数据库数据：

 浏览器显示的数据就是从数据库当中查出来的数据，项目已经成功连接到数据库了

打印运行日志：

浏览器访问成功，但是没有输出运行的日志，看不到执行的Sql语句，就很不方便

我们在application.yml配置一下就好了

# 日志配置 logging: level: com: debug org.springframework: warn

重启项目，再次运行

数据库连接结束，

下章预告：对数据库执行CRUD

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