@Configuration
public class MybatisPlusConfig {
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        interceptor.addInnerInterceptor(new OptimisticLockerInnerInterceptor());
        interceptor.addInnerInterceptor(new BlockAttackInnerInterceptor()); // ← 推荐
        return interceptor;
    }
}

mybatis-plus:
  global-config:
    db-config:
      id-type: auto                    # 主键自增
      logic-delete-field: deleted      # 逻辑删除字段
      logic-delete-value: 1
      logic-not-delete-value: 0
      insert-strategy: not_null
      update-strategy: not_null
  configuration:
    map-underscore-to-camel-case: true
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl  # 开发环境

// ✅ 推荐：LambdaQueryWrapper（类型安全）
LambdaQueryWrapper<User> wrapper = Wrappers.lambdaQuery();
wrapper.eq(User::getUsername, "张三")
       .ge(User::getAge, 18)
       .in(User::getStatus, List.of(1, 2))
       .orderByDesc(User::getCreateTime)
       .last("limit 10");  // 慎用 last——与分页冲突
List<User> list = userMapper.selectList(wrapper);

// ✅ 简化：lambdaQuery() 链式调用
List<User> adults = userService.lambdaQuery()
    .ge(User::getAge, 18)
    .in(User::getStatus, Arrays.asList(1, 2))
    .orderByDesc(User::getCreateTime)
    .list();

// ✅ 更新：lambdaUpdate()
userService.lambdaUpdate()
    .eq(User::getUsername, "张三")
    .set(User::getEmail, "new@test.com")
    .update();

// ❌ 避免：QueryWrapper（字符串硬编码，重构时不易发现）
// QueryWrapper<User> wrapper = new QueryWrapper<>();
// wrapper.eq("user_name", "张三");  // 字段名写死，重构时断裂

// 通用分页查询参数
@Data
public class PageQuery {
    @Min(1) private Integer pageNo = 1;
    @Min(1) @Max(5000) private Integer pageSize = 10;
    private String sortBy;
    private boolean isAsc = true;

    public <T> Page<T> toPage() {
        Page<T> page = Page.of(pageNo, pageSize);
        if (StrUtil.isNotBlank(sortBy)) {
            page.addOrder(new OrderItem(sortBy, isAsc));
        }
        return page;
    }
}

// 通用分页返回
@Data
public class PageDTO<T> {
    private Long total;
    private Long pages;
    private List<T> list;

    public static <T> PageDTO<T> of(IPage<T> page) {
        PageDTO<T> dto = new PageDTO<>();
        dto.setTotal(page.getTotal());
        dto.setPages(page.getPages());
        dto.setList(page.getRecords());
        return dto;
    }
}

// 使用
public PageDTO<User> queryUsers(PageQuery query) {
    Page<User> page = userService.page(query.toPage(),
        Wrappers.lambdaQuery<User>().ge(User::getAge, 18));
    return PageDTO.of(page);
}

@Data
@TableName("sys_user")
public class User {
    @TableId(type = IdType.AUTO)
    private Long id;

    private String username;
    private String email;

    @Version private Integer version;          // ← 乐观锁(更新时自动+1)

    @TableLogic private Integer deleted;        // ← 逻辑删除(0=正常, 1=删除)

    @TableField(fill = FieldFill.INSERT)
    private LocalDateTime createTime;           // ← 插入时自动填充

    @TableField(fill = FieldFill.INSERT_UPDATE)
    private LocalDateTime updateTime;           // ← 更新时自动填充
}

// 自动填充处理器
@Component
public class MyMetaObjectHandler implements MetaObjectHandler {
    @Override
    public void insertFill(MetaObject metaObject) {
        this.strictInsertFill(metaObject, "createTime", LocalDateTime.class, LocalDateTime.now());
        this.strictInsertFill(metaObject, "updateTime", LocalDateTime.class, LocalDateTime.now());
    }

    @Override
    public void updateFill(MetaObject metaObject) {
        this.strictUpdateFill(metaObject, "updateTime", LocalDateTime.class, LocalDateTime.now());
    }
}

// ActiveRecord: Entity extends Model<T>
@Data
@EqualsAndHashCode(callSuper = true) // ← 必须加
@TableName("sys_user")
public class User extends Model<User> {
    @TableId private Long id;
    private String username;
}
// 使用
User user = new User();
user.setUsername("张三");
user.insert();                         // 直接操作
User found = user.selectById(1L);
user.setEmail("new@test.com");
user.updateById();
user.deleteById();

// Mapper 模式: 独立 Mapper 接口 + IService
public interface UserMapper extends BaseMapper<User> {}

public interface UserService extends IService<User> {}
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {}
// 使用
userService.save(user);
userService.getById(1L);
userService.lambdaQuery().eq(User::getUsername, "张三").list();

// 配置 BlockAttackInnerInterceptor 后：
userService.update(new User().setEmail("all@test.com"));  // ❌ 抛出异常
// 必须加 where 条件
userService.lambdaUpdate()
    .eq(User::getStatus, "ACTIVE")
    .set(User::getEmail, "all@test.com")
    .update();  // ✅ 安全