Mybatis plus+spring+boot第一章

一、创建spring boot项目，引入依赖，引入lombock依赖， mysql-connector-java    mybatis-plus-boot-starter  junit  spring-test 依赖

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.6.4</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.yinminneng</groupId>
    <artifactId>mybatisplus01</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>mybatisplus01</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
<!--        引入mybatisplus-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.5.1</version>
        </dependency>
        <!-- 导入mysql -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-test</artifactId>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

　　

二、创建数据库表和数据库数据

DROP TABLE IF EXISTS user;

CREATE TABLE user
(
    id BIGINT(20) NOT NULL COMMENT '主键ID',
    name VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名',
    age INT(11) NULL DEFAULT NULL COMMENT '年龄',
    email VARCHAR(50) NULL DEFAULT NULL COMMENT '邮箱',
    PRIMARY KEY (id)
);


DELETE FROM user;
INSERT INTO user (id, name, age, email) VALUES
(1, 'Jone', 18, 'test1@baomidou.com'),
(2, 'Jack', 20, 'test2@baomidou.com'),
(3, 'Tom', 28, 'test3@baomidou.com'),
(4, 'Sandy', 21, 'test4@baomidou.com'),
(5, 'Billie', 24, 'test5@baomidou.com');

　　

三、创建配置文件，application.yml，删除application.properties

# DataSource Config
server:
  port: 8099
spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mybatisdb?autoReconnect=true&useUnicode=true&characterEncoding=utf8&zeroDateTimeBehavior=CONVERT_TO_NULL&useSSL=false&nullCatalogMeansCurrent=true
    username: root
    password: root123

　　

四、创建实体类，user，项目结构如下

package com.yinminneng.mybatisplus01.entities;

import lombok.Data;

@Data
public class User {
    private Long id;
    private String name;
    private Integer age;
    private String email;
}

　五、创建userMapper类，继承basemapper

package com.yinminneng.mybatisplus01.mapper;


import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.yinminneng.mybatisplus01.entities.User;
import org.springframework.stereotype.Component;

public interface UserMapper extends BaseMapper<User> {

}

　　

六、配置mapper扫描包，注解MapperScan

package  com.yinminneng.mybatisplus01;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("com.yinminneng.mybatisplus01.mapper")
public class Mybatisplus01Application {
    public static void main(String[] args) {
        SpringApplication.run(Mybatisplus01Application.class, args);
    }

}

　　

七、添加测试类，测试

package com.yinminneng.mybatisplus01.tests;

import com.yinminneng.mybatisplus01.entities.User;
import com.yinminneng.mybatisplus01.mapper.UserMapper;
import org.junit.Assert;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import java.util.List;

//单元测试要加runwith，否则无法自动注入
@SpringBootTest
@RunWith(SpringRunner.class)
public class SampleTest {

    @Autowired
    private UserMapper userMapper;
    @Test
    public void  select(){
        List<User> list = userMapper.selectList(null);
        //junit测试单元有的
        Assert.assertEquals(5,list.size());
        list.forEach(System.out::println);
    }
}