Mybatis批量新增的三种实现方式

 <!-- 数据库驱动 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.48</version>
        </dependency>

        <!-- lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>

        <!-- mybatis-plus -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.0.5</version>
        </dependency>

        <!--        web-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <!--test-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

@Repository // 代表持久层
public interface DeptMapper  {

    int addDept(Dept dept);

    int foreachAdd(List<Dept> list);
}

@MapperScan(“com.example.demo.dao”)

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="com.example.demo.dao.DeptMapper">


<!--普通新增-->
    <insert id="addDept" parameterType="com.example.demo.pojo.Dept">
        INSERT INTO dept (dname, db_source) VALUES (#{dname},#{dbSource})
    </insert>


    <!--foreachMySql写法-->
    <insert id="foreachAdd"  parameterType="java.util.List">
        insert into dept (
        dname,
        db_source

        )
        values
        <foreach collection="list" item="dept" index="index" separator="," >
            (
            #{dept.dname,jdbcType=VARCHAR},
            #{dept.dbSource,jdbcType=VARCHAR}

            )
        </foreach>
    </insert>


</mapper>

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Dept {
  private long deptno;
  private String dname;
  private String dbSource;
}

# mysql 5 驱动不同 com.mysql.jdbc.Driver
# mysql 8 驱动不同com.mysql.cj.jdbc.Driver、需要增加时区的配置
serverTimezone=GMT%2B8
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.url=jdbc:mysql://localhost:3306/db01?useSSL=false&useUnicode=true&characterEncoding=utf-8&serverTimezone=GMT%2B8
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

mybatis-plus.mapper-locations=classpath:mapping/*Mapper.xml

@SpringBootTest
class DemoApplicationTests {


    @Autowired
    private DeptMapper deptMapper;


    //测试数据
    public List<Dept> textData(){
        ArrayList<Dept> deptList = new ArrayList<>();
        for (int i = 0; i < 1000; i++) {
            Dept dept = new Dept();
            dept.setDname("foreach");
            dept.setDbSource("db02");
            deptList.add(dept);
        }
        return deptList;
    }

//    循环插入
    @Test
    public void add(){
        List<Dept> textData = textData();//测试数据
        long start = System.currentTimeMillis();//开始时间
        for(Dept dept : textData){
            deptMapper.addDept(dept);
        }
        System.out.println(System.currentTimeMillis() - start);//统计时间
    }

//    foreach标签
    @Test
    public void foreach(){
        List<Dept> textData = textData();//测试数据
        long start = System.currentTimeMillis();//开始时间
        deptMapper.foreachAdd(textData);
        System.out.println(System.currentTimeMillis() - start);//统计时间
    }

    @Autowired
    private SqlSessionFactory sqlSessionFactory;

    @Test
    public void testInsertBatch(){

        List<Dept> textData = textData();//测试数据
        long start = System.currentTimeMillis();//开始时间
        SqlSession sqlSession = sqlSessionFactory.openSession(ExecutorType.BATCH,false);
        DeptMapper studentMapperNew = sqlSession.getMapper(DeptMapper.class);
        textData.stream().forEach(student -> studentMapperNew.addDept(student));
        sqlSession.commit();
        sqlSession.clearCache();
        System.out.println(System.currentTimeMillis() - start);//统计时间
    }
}