Java MyBatis-Plus之初始MyBatis

<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus</artifactId>
<version>maven 官方最新版本号为准</version>
</dependency>

<dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-WEB</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>Mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
            <scope>runtime</scope>
        </dependency>
<!--        mybatis-plus-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.3</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

spring:
  datasource:
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=GMT%2B8
    username: root
    passWord: 123456
mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl  #日志信息

package com.liuhaiyang.entity;
import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
@TableName(value = "t_student")  //指定表的名称
public class Address {
    
    @TableId(value = "id",type = IdType.AUTO)
    private Integer id;
    //当属性名和字段名不一致时，指定属性和列名的对应关系（@TableField）value指列名
    @TableField(value = "name")
    private String name;
    @TableField(value = "age")
    private Integer age;
    public Address() {
    }
    public Address(String name, Integer age) {
        this.name = name;
        this.age = age;
    }
    public Integer getId() {
        return id;
    }
    public void setId(Integer 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;
    }
    @Override
    public String toString() {
        return "Address{" +
                "id=" + id +
                ", name='" + name + '\'' +
                ", age=" + age +
                '}';
    }
}

package com.liuhaiyang.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.liuhaiyang.entity.Address;
public interface AddreSSMapper extends BaseMapper<Address> {
}

@SpringBootApplication
@MapperScan(value = "com.liuhaiyang.mapper")  //扫描器
public class MybatisPlusApplication {
    public static void main(String[] args) {
        SpringApplication.run(MybatisPlusApplication.class, args);
    }
}

@SpringBootApplication
@MapperScan(value = "com.liuhaiyang.mapper")  //扫描器
public class MybatisPlusApplication {
    public static void main(String[] args) {
        SpringApplication.run(MybatisPlusApplication.class, args);
    }
}

 @Test
    public void updateaddress() {
        Address address=new Address();
        address.setId(10);
        address.setName("赵六");
        //判断字段是否会进行更新，依据字段是否为null，
        //如果非null，则加入set语句中；为null，则不加入set语句
        int rows=addressMapper.updateById(address);
        System.out.println("update的结果是：" + rows);
    }

 @Test
    public void selectaddress() {
        Address rows=addressMapper.selectById(10);
        System.out.println("select的结果是：" + rows);
    }

 @Test
    public void deleteaddress() {
        int rows=addressMapper.deleteById(10);
        System.out.println("delete的结果是：" + rows);
    }