面试官：MyBatis批量插入的五种方式，哪种最强？
前言
这里我列举了MyBatis和MyBatis-Plus常用的五种批量插入的方式，进行了详细的总结归纳，写的非常详细，整体思路清晰明了，只分享干货。
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准备工作
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MyBatis利用For循环批量插入
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MyBatis的手动批量提交
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MyBatis以集合方式批量新增（推荐）
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MyBatis-Plus提供的SaveBatch方法
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MyBatis-Plus提供的InsertBatchSomeColumn方法（推荐）
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总结
一、准备工作
1、导入pom.xml依赖
mysql
mysql-connector-java
runtime
org.mybatis.spring.boot
mybatis-spring-boot-starter
2.2.2
com.baomidou
mybatis-plus-boot-starter
3.5.2
org.projectlombok
lombok
true
2、配置yml文件
server:
port: 8080
spring:
datasource:
username: mysql用户名
password: mysql密码
url: jdbc:mysql://localhost:3306/数据库名字?useUnicode=true&characterEncoding=utf-8&useSSL=false&serverTimezone=UTC
driver-class-name: com.mysql.cj.jdbc.Driver
mybatis:
mapper-locations: classpath:mapping/*.xml
3、公用的User类
@Data
public class User {
private int id;
private String username;
private String password;
}
二、MyBatis利用For循环批量插入
1、编写UserService服务类，测试一万条数据耗时情况
@Service
public class UserService {
@Resource
private UserMapper userMapper;
public void InsertUsers(){
long start = System.currentTimeMillis();
for(int i = 0 ;i < 10000; i++) {
User user = new User();
user.setUsername("name" + i);
user.setPassword("password" + i);
userMapper.insertUsers(user);
}
long end = System.currentTimeMillis();
System.out.println("一万条数据总耗时：" + (end-start) + "ms" );
}
}
2、编写UserMapper接口
@Mapper
public interface UserMapper {
Integer insertUsers(User user);
}
3、编写UserMapper.xml文件
INSERT INTO user (username, password)
VALUES(#{username}, #{password})
4、进行单元测试
@SpringBootTest
class DemoApplicationTests {
@Resource
private UserService userService;
@Test
public void insert(){
userService.InsertUsers();
}
}
5、结果输出
一万条数据总耗时：26348ms
三、MyBatis的手动批量提交
1、其他保持不变，Service层作稍微的变化
@Service
public class UserService {
@Resource
private UserMapper userMapper;
@Resource
private SqlSessionTemplate sqlSessionTemplate;
public void InsertUsers(){
//关闭自动提交
SqlSession sqlSession = sqlSessionTemplate.getSqlSessionFactory().openSession(ExecutorType.BATCH, false);
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
long start = System.currentTimeMillis();
for(int i = 0 ;i < 10000; i++) {
User user = new User();
user.setUsername("name" + i);
user.setPassword("password" + i);
userMapper.insertUsers(user);
}
sqlSession.commit();
long end = System.currentTimeMillis();
System.out.println("一万条数据总耗时：" + (end-start) + "ms" );
}
}
2、结果输出
一万条数据总耗时：24516ms
四、MyBatis以集合方式批量新增（推荐）
1、编写UserService服务类
@Service
public class UserService {
@Resource
private UserMapper userMapper;
public void InsertUsers(){
long start = System.currentTimeMillis();
List userList = new ArrayList<>();
User user;
for(int i = 0 ;i < 10000; i++) {
user = new User();
user.setUsername("name" + i);
user.setPassword("password" + i);
userList.add(user);
}
userMapper.insertUsers(userList);
long end = System.currentTimeMillis();
System.out.println("一万条数据总耗时：" + (end-start) + "ms" );
}
}
2、编写UserMapper接口
@Mapper
public interface UserMapper {
Integer insertUsers(List userList);
}
3、编写UserMapper.xml文件
INSERT INTO user (username, password)
VALUES
(#{user.username}, #{user.password})
4、输出结果
一万条数据总耗时：521ms
五、MyBatis-Plus提供的SaveBatch方法
1、编写UserService服务
@Service
public class UserService extends ServiceImpl implements IService {
public void InsertUsers(){
long start = System.currentTimeMillis();
List userList = new ArrayList<>();
User user;
for(int i = 0 ;i < 10000; i++) {
user = new User();
user.setUsername("name" + i);
user.setPassword("password" + i);
userList.add(user);
}
saveBatch(userList);
long end = System.currentTimeMillis();
System.out.println("一万条数据总耗时：" + (end-start) + "ms" );
}
}
2、编写UserMapper接口
@Mapper
public interface UserMapper extends BaseMapper {
}
3、单元测试结果
一万条数据总耗时：24674ms
六、MyBatis-Plus提供的InsertBatchSomeColumn方法（推荐）
1、编写EasySqlInjector 自定义类
public class EasySqlInjector extends DefaultSqlInjector {
@Override
public List getMethodList(Class mapperClass, TableInfo tableInfo) {
// 注意：此SQL注入器继承了DefaultSqlInjector(默认注入器)，调用了DefaultSqlInjector的getMethodList方法，保留了mybatis-plus的自带方法
List methodList = super.getMethodList(mapperClass, tableInfo);
methodList.add(new InsertBatchSomeColumn(i -> i.getFieldFill() != FieldFill.UPDATE));
return methodList;
}
}
2、定义核心配置类注入此Bean
@Configuration
public class MybatisPlusConfig {
@Bean
public EasySqlInjector sqlInjector() {
return new EasySqlInjector();
}
}
3、编写UserService服务类
public class UserService{
@Resource
private UserMapper userMapper;
public void InsertUsers(){
long start = System.currentTimeMillis();
List userList = new ArrayList<>();
User user;
for(int i = 0 ;i < 10000; i++) {
user = new User();
user.setUsername("name" + i);
user.setPassword("password" + i);
userList.add(user);
}
userMapper.insertBatchSomeColumn(userList);
long end = System.currentTimeMillis();
System.out.println("一万条数据总耗时：" + (end-start) + "ms" );
}
}
4、编写EasyBaseMapper接口
public interface EasyBaseMapper extends BaseMapper {
/**
* 批量插入 仅适用于mysql
*
* @param entityList 实体列表
* @return 影响行数
*/
Integer insertBatchSomeColumn(Collection entityList);
}
5、编写UserMapper接口
@Mapper
public interface UserMapper extends EasyBaseMapper {
}
6、单元测试结果
一万条数据总耗时：575ms