MyBatis的五种批量插入详解
作者:谁是黄黄
MyBatis
MyBatis是一款半自动的ORM持久层框架,具有较高的SQL灵活性,支持高级映射(一对一,一对多),动态SQL,延迟加载和缓存等特性,但它的数据库无关性较低
用mybatis进行开发,需要手动编写SQL语句。而全自动的ORM框架,如hibernate,则不需要编写SQL语句。
用hibernate开发,只需要定义好ORM映射关系,就可以直接进行CRUD操作了。
由于mybatis需要手写SQL语句,所以它有较高的灵活性,可以根据需要,自由地对SQL进行定制,也因为要手写SQL,当要切换数据库时,SQL语句可能就要重写,因为不同的数据库有不同的方言(Dialect),所以mybatis的数据库无关性低。
一.直接循环插入
@RestController @RequestMapping("/mybatis3/user") @RequiredArgsConstructor public class UserController { private final IUserService iUserService; @GetMapping("/one") public Long one(){ return iUserService.add(); } } Long add(); @Service @RequiredArgsConstructor public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements IUserService { private final UserMapper userMapper; @Override public Long add() { 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("耗时:"+( end - start ) + "ms"); return (end-start); } } Integer insertUsers(User user); <insert id="insertUsers" > insert into user(username,password) values (#{username}, #{password}) </insert>
最终耗时:14s多
二.关闭MySql自动提交,手动进行循环插入提交
@RestController @RequestMapping("/mybatis3/user") @RequiredArgsConstructor public class UserController { private final IUserService iUserService; @GetMapping("/one") public Long one(){ return iUserService.add(); } } Long add2(); @Service @RequiredArgsConstructor public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements IUserService { private final UserMapper userMapper; // 手动开启sql的批量提交 private final SqlSessionTemplate sqlSessionTemplate; @Override public Long add2(){ //关闭自动提交 SqlSession sqlSession = sqlSessionTemplate.getSqlSessionFactory().openSession(ExecutorType.BATCH, false); UserMapper mapper = 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); mapper.insertUsers(user); } //自动提交SQL sqlSession.commit(); long end = System.currentTimeMillis(); System.out.println("耗时:"+( end - start ) + "ms"); return (end-start); } }
平均:0.12s
第三种:用List集合的方式插入数据库(推荐)
@RestController @RequestMapping("/mybatis3/user") @RequiredArgsConstructor public class UserController { private final IUserService iUserService; @GetMapping("/one3") public Long one3(){ return iUserService.add3(); } } Long add3(); @Service @RequiredArgsConstructor public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements IUserService { private final UserMapper userMapper; @Override public Long add3(){ long start = System.currentTimeMillis(); List<User> 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.insertUsersThree(userList); long end = System.currentTimeMillis(); System.out.println("耗时:"+( end - start ) + "ms"); return (end-start); } } Integer insertUsersThree(List<User> userList); <insert id="insertUsersThree"> insert into user(username,password) values <foreach collection="userList" item="user" separator=","> (#{user.username},#{user.password}) </foreach> </insert>
第四种: MyBatis-Plus提供的SaveBatch方法
@RestController @RequestMapping("/mybatis3/user") @RequiredArgsConstructor public class UserController { private final IUserService iUserService; @GetMapping("/one4") public Long one4(){ return iUserService.add4(); } } Long add4(); @Service @RequiredArgsConstructor public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements IUserService { private final UserMapper userMapper; @Override public Long add4() { long start = System.currentTimeMillis(); List<User> 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("耗时:"+( end - start ) + "ms"); return (end-start); } }
直接报错:
看报错信息:
长串:Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.dao.DataIntegrityViolationException: com.huang.mybatis3.mapper.UserMapper.insert (batch index #1) failed. Cause: java.sql.BatchUpdateException: Data truncation: Out of range value for column ‘id’ at row 1 ; Data truncation: Out of range value for column ‘id’ at row 1; nested exception is java.sql.BatchUpdateException: Data truncation: Out of range value for column ‘id’ at row 1] with root cause
短串:Data truncation: Out of range value for column ‘id’ at row 1
翻译一下:
可以发现就是我们的id超出范围:
int类型改为bigint即可
故此我们可以得出一个结论:设置数据库id的时候设置为bigint还是蛮好的哈
平均时间:0.2s
第五种 MyBatis-Plus提供的InsertBatchSomeColumn方法(推荐)
InsertBatchSomeColumn方法了解
这个类的注解就写的很明白
扩展这个InsertBatchSomeColumn方法
@Slf4j public class EasySqlInjector extends DefaultSqlInjector { @Override public List<AbstractMethod> 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<AbstractMethod> methodList = super.getMethodList(mapperClass, tableInfo); methodList.add(new InsertBatchSomeColumn(i -> i.getFieldFill() != FieldFill.UPDATE)); log.info("扩展的getMethodList方法被框架调用了"); return methodList; } }
扩展的方法注入bean容器
/** * @author Stone * @date 2023/1/3 * @apiNote */ @Configuration public class MybatisPlusConfig { @Bean public EasySqlInjector sqlInjector(){ return new EasySqlInjector(); } }
创建一个Mapper去实现我们的扩展的飞方法
public interface EasySqlInjectMapper<T> extends BaseMapper<T> { /** * 批量插入 仅适用于mysql * * @param entityList 实体列表 * @return 影响行数 */ Integer insertBatchSomeColumn(Collection<T> entityList); }
业务层
@Override public Long add5() { long start = System.currentTimeMillis(); List<User> 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("耗时:"+( end - start ) + "ms"); return (end-start); }
耗时: 0.2 s
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