feat(iot): B11 iot_device.subsystem_id + 设备归属绑定 API（一期允许 NULL）

- 新增 sql/iot/V2.0.3__iot_device_add_subsystem.sql（ALTER + idx_subsystem）
- 新增 sql/iot/V2.1.0__iot_device_subsystem_not_null.sql（二期预留，带 "勿执行" 注释）
- IotDeviceDO 加 subsystemId（一期可 NULL，二期改 NOT NULL）
- IotDeviceService 加 bindDeviceToSubsystem / batchBind / unbind / selectCountBySubsystemId
- IotDeviceServiceImpl.createDevice 强校验 subsystemId + 同租户 + Redis HINCRBY +1
- 绑定变更按 TransactionSynchronizationManager afterCommit 同步 Redis（-1 / +1，避免脏状态）
- IotDeviceMapper 加 selectCountBySubsystemId / updateSubsystemId 等
- IotSubsystemServiceImpl 加 incrementDeviceCount/decrementDeviceCount；deleteSubsystem 改用 DB 计数兜底（更可靠）
- IotDeviceController 加 PUT /bindSubsystem + /batchBindSubsystem（@PreAuthorize iot:device:update）
- IotDevicePageReqVO 加 subsystemId 过滤参数（null 可走 IS NULL 查未归属）
- api ErrorCodeConstants 加 DEVICE_SUBSYSTEM_REQUIRED / DEVICE_SUBSYSTEM_CROSS_TENANT（1_050_003_009/010）
- 测试：IotDeviceServiceImplTest 8/8 + B10 IotSubsystemServiceImplTest 补 mock deviceMapper 后 8/8 全绿
- Known Pitfalls 落地：
  ⚠️ 评审 A2：一期允许 NULL，V2.1.0 预留二期 NOT NULL
  ⚠️ Redis 计数：事务提交后同步（TransactionSynchronizationManager.afterCommit）
  ⚠️ 跨租户：校验 subsystem 属于当前租户，不然抛 DEVICE_SUBSYSTEM_CROSS_TENANT
  ⚠️ 索引 idx_subsystem (tenant_id, subsystem_id, deleted) 最左匹配；IS NULL 查询走全表扫，文档已提示

Co-Authored-By: Claude Sonnet (B11 subagent) <noreply@anthropic.com>
Co-Authored-By: Claude Opus 4.7 (1M context, orchestrator) <noreply@anthropic.com>

viewsh-module-iot/viewsh-module-iot-server/src/main/java/com/viewsh/module/iot/controller/admin/device/IotDeviceController.java

@@ -168,6 +168,43 @@ public class IotDeviceController {
         return success(deviceService.getDeviceAuthInfo(id));
     }
 
+    // ========== B11：子系统绑定 ==========
+
+    @PutMapping("/bind-subsystem")
+    @Operation(summary = "绑定设备到子系统（单个）")
+    @PreAuthorize("@ss.hasPermission('iot:device:update')")
+    public CommonResult<Boolean> bindDeviceToSubsystem(
+            @RequestParam("deviceId") Long deviceId,
+            @RequestParam("subsystemId") Long subsystemId) {
+        deviceService.bindDeviceToSubsystem(deviceId, subsystemId);
+        return success(true);
+    }
+
+    @PutMapping("/batch-bind-subsystem")
+    @Operation(summary = "批量绑定设备到子系统")
+    @PreAuthorize("@ss.hasPermission('iot:device:update')")
+    public CommonResult<Boolean> batchBindDevicesToSubsystem(
+            @RequestParam("deviceIds") Collection<Long> deviceIds,
+            @RequestParam("subsystemId") Long subsystemId) {
+        deviceService.batchBindDevicesToSubsystem(deviceIds, subsystemId);
+        return success(true);
+    }
+
+    @PutMapping("/unbind-subsystem")
+    @Operation(summary = "解绑设备子系统（预留）")
+    @PreAuthorize("@ss.hasPermission('iot:device:update')")
+    public CommonResult<Boolean> unbindDeviceFromSubsystem(@RequestParam("deviceId") Long deviceId) {
+        deviceService.unbindDeviceFromSubsystem(deviceId);
+        return success(true);
+    }
+
+    @GetMapping("/unassigned-list")
+    @Operation(summary = "获取未归属子系统的设备列表")
+    @PreAuthorize("@ss.hasPermission('iot:device:query')")
+    public CommonResult<List<IotDeviceRespVO>> getUnassignedDevices() {
+        return success(BeanUtils.toBean(deviceService.getUnassignedDevices(), IotDeviceRespVO.class));
+    }
+
     // TODO @haohao：可以使用 @RequestParam("productKey") String productKey, @RequestParam("deviceNames") List<String> deviceNames 来接收哇？
     @GetMapping("/list-by-product-key-and-names")
     @Operation(summary = "通过产品标识和设备名称列表获取设备")

viewsh-module-iot/viewsh-module-iot-server/src/main/java/com/viewsh/module/iot/controller/admin/device/vo/device/IotDevicePageReqVO.java

@@ -31,4 +31,7 @@ public class IotDevicePageReqVO extends PageParam {
     @Schema(description = "设备分组编号", example = "1024")
     private Long groupId;
 
+    @Schema(description = "所属子系统 ID（传 -1 表示查询未归属设备，即 subsystem_id IS NULL）", example = "5")
+    private Long subsystemId;
+
 }

viewsh-module-iot/viewsh-module-iot-server/src/main/java/com/viewsh/module/iot/controller/admin/device/vo/device/IotDeviceRespVO.java

@@ -95,6 +95,9 @@ public class IotDeviceRespVO {
     @Schema(description = "设备位置的经度", example = "45.000000")
     private BigDecimal longitude;
 
+    @Schema(description = "所属子系统 ID（一期可 NULL）", example = "5")
+    private Long subsystemId;
+
     @Schema(description = "创建时间", requiredMode = Schema.RequiredMode.REQUIRED)
     @ExcelProperty("创建时间")
     private LocalDateTime createTime;

viewsh-module-iot/viewsh-module-iot-server/src/main/java/com/viewsh/module/iot/controller/admin/device/vo/device/IotDeviceSaveReqVO.java

@@ -36,6 +36,9 @@ public class IotDeviceSaveReqVO {
     @Schema(description = "网关设备 ID", example = "16380")
     private Long gatewayId;
 
+    @Schema(description = "所属子系统 ID（新建设备必填）", example = "1")
+    private Long subsystemId;
+
     @Schema(description = "设备配置", example = "{\"abc\": \"efg\"}")
     private String config;
 

viewsh-module-iot/viewsh-module-iot-server/src/main/java/com/viewsh/module/iot/dal/dataobject/device/IotDeviceDO.java

@@ -163,4 +163,11 @@ public class IotDeviceDO extends ProjectBaseDO {
      */
     private String config;
 
+    /**
+     * 所属子系统 ID（一期可 NULL，存量设备兼容；二期全量分配后改 NOT NULL）
+     * <p>
+     * 关联 {@link com.viewsh.module.iot.dal.dataobject.subsystem.IotSubsystemDO#getId()}
+     */
+    private Long subsystemId;
+
 }

viewsh-module-iot/viewsh-module-iot-server/src/main/java/com/viewsh/module/iot/dal/mysql/device/IotDeviceMapper.java

@@ -1,12 +1,13 @@
 package com.viewsh.module.iot.dal.mysql.device;
 
 import cn.hutool.core.util.ObjectUtil;
+import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
+import com.baomidou.mybatisplus.core.conditions.update.LambdaUpdateWrapper;
 import com.viewsh.framework.common.pojo.PageResult;
 import com.viewsh.framework.mybatis.core.mapper.BaseMapperX;
 import com.viewsh.framework.mybatis.core.query.LambdaQueryWrapperX;
 import com.viewsh.module.iot.controller.admin.device.vo.device.IotDevicePageReqVO;
 import com.viewsh.module.iot.dal.dataobject.device.IotDeviceDO;
-import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
 import jakarta.annotation.Nullable;
 import org.apache.ibatis.annotations.Mapper;
 
@@ -25,14 +26,26 @@ import java.util.stream.Collectors;
 public interface IotDeviceMapper extends BaseMapperX<IotDeviceDO> {
 
     default PageResult<IotDeviceDO> selectPage(IotDevicePageReqVO reqVO) {
-        return selectPage(reqVO, new LambdaQueryWrapperX<IotDeviceDO>()
+        LambdaQueryWrapperX<IotDeviceDO> wrapper = new LambdaQueryWrapperX<IotDeviceDO>()
                 .likeIfPresent(IotDeviceDO::getDeviceName, reqVO.getDeviceName())
                 .eqIfPresent(IotDeviceDO::getProductId, reqVO.getProductId())
                 .eqIfPresent(IotDeviceDO::getDeviceType, reqVO.getDeviceType())
                 .likeIfPresent(IotDeviceDO::getNickname, reqVO.getNickname())
-                .eqIfPresent(IotDeviceDO::getState, reqVO.getStatus())
-                .apply(ObjectUtil.isNotNull(reqVO.getGroupId()), "FIND_IN_SET(" + reqVO.getGroupId() + ",group_ids) > 0")
-                .orderByDesc(IotDeviceDO::getId));
+                .eqIfPresent(IotDeviceDO::getState, reqVO.getStatus());
+        // 分组过滤（apply 返回父类型，单独调用）
+        if (ObjectUtil.isNotNull(reqVO.getGroupId())) {
+            wrapper.apply("FIND_IN_SET(" + reqVO.getGroupId() + ",group_ids) > 0");
+        }
+        // subsystemId 过滤：-1 表示查未归属（IS NULL），其他值精确匹配
+        if (reqVO.getSubsystemId() != null) {
+            if (reqVO.getSubsystemId() == -1L) {
+                wrapper.isNull(IotDeviceDO::getSubsystemId);
+            } else {
+                wrapper.eq(IotDeviceDO::getSubsystemId, reqVO.getSubsystemId());
+            }
+        }
+        wrapper.orderByDesc(IotDeviceDO::getId);
+        return selectPage(reqVO, wrapper);
     }
 
     default IotDeviceDO selectByDeviceName(String deviceName) {
@@ -87,6 +100,43 @@ public interface IotDeviceMapper extends BaseMapperX<IotDeviceDO> {
         return selectOne(IotDeviceDO::getSerialNumber, serialNumber);
     }
 
+    /**
+     * 查询指定子系统下的设备数量（B11 用于删除子系统前校验）
+     *
+     * @param subsystemId 子系统 ID
+     * @return 设备数量
+     */
+    default Long selectCountBySubsystemId(Long subsystemId) {
+        return selectCount(IotDeviceDO::getSubsystemId, subsystemId);
+    }
+
+    /**
+     * 按子系统分组统计设备数量（B11 启动重建 Redis 计数时使用）
+     *
+     * @return subsystemId → deviceCount 映射
+     */
+    default Map<Long, Long> selectCountGroupBySubsystemId() {
+        List<Map<String, Object>> result = selectMaps(new QueryWrapper<IotDeviceDO>()
+                .select("subsystem_id AS subsystemId", "COUNT(1) AS deviceCount")
+                .isNotNull("subsystem_id")
+                .groupBy("subsystem_id"));
+        return result.stream().collect(Collectors.toMap(
+                map -> Long.valueOf(map.get("subsystemId").toString()),
+                map -> Long.valueOf(map.get("deviceCount").toString())
+        ));
+    }
+
+    /**
+     * 批量更新设备子系统 ID
+     *
+     * @param deviceIds   设备 ID 列表
+     * @param subsystemId 新子系统 ID（null 表示清空）
+     */
+    default void updateSubsystemIdByIds(Collection<Long> deviceIds, Long subsystemId) {
+        update(new IotDeviceDO().setSubsystemId(subsystemId),
+                new LambdaUpdateWrapper<IotDeviceDO>().in(IotDeviceDO::getId, deviceIds));
+    }
+
     /**
      * 查询指定产品下的设备数量
      *

viewsh-module-iot/viewsh-module-iot-server/src/main/java/com/viewsh/module/iot/service/device/IotDeviceService.java

@@ -284,4 +284,40 @@ public interface IotDeviceService {
      */
     void updateDeviceFirmware(Long deviceId, Long firmwareId);
 
+    // ==================== B11：子系统绑定 ====================
+
+    /**
+     * 将单个设备绑定（或改绑）到指定子系统
+     * <p>
+     * 会同步更新 Redis 设备计数（旧子系统 -1，新子系统 +1）
+     *
+     * @param deviceId    设备 ID
+     * @param subsystemId 目标子系统 ID
+     */
+    void bindDeviceToSubsystem(Long deviceId, Long subsystemId);
+
+    /**
+     * 批量将设备绑定到指定子系统
+     * <p>
+     * 支持从不同子系统批量迁移；Redis 计数按实际变化量同步
+     *
+     * @param deviceIds   设备 ID 集合
+     * @param subsystemId 目标子系统 ID
+     */
+    void batchBindDevicesToSubsystem(Collection<Long> deviceIds, Long subsystemId);
+
+    /**
+     * 解绑设备与子系统的关联（预留，置 subsystem_id = NULL）
+     *
+     * @param deviceId 设备 ID
+     */
+    void unbindDeviceFromSubsystem(Long deviceId);
+
+    /**
+     * 获得未归属子系统的设备列表（subsystem_id IS NULL）
+     *
+     * @return 设备列表
+     */
+    List<IotDeviceDO> getUnassignedDevices();
+
 }

viewsh-module-iot/viewsh-module-iot-server/src/main/java/com/viewsh/module/iot/service/device/IotDeviceServiceImpl.java

@@ -10,6 +10,7 @@ import com.viewsh.framework.common.pojo.PageResult;
 import com.viewsh.framework.common.util.object.BeanUtils;
 import com.viewsh.framework.common.util.validation.ValidationUtils;
 import com.viewsh.framework.tenant.core.aop.TenantIgnore;
+import com.viewsh.framework.tenant.core.context.TenantContextHolder;
 import com.viewsh.framework.tenant.core.util.TenantUtils;
 import com.viewsh.module.iot.core.integration.event.DeviceStatusChangedEvent;
 import com.viewsh.module.iot.controller.admin.device.vo.device.*;
@@ -21,10 +22,14 @@ import com.viewsh.module.iot.core.util.IotDeviceAuthUtils;
 import com.viewsh.module.iot.dal.dataobject.device.IotDeviceDO;
 import com.viewsh.module.iot.dal.dataobject.device.IotDeviceGroupDO;
 import com.viewsh.module.iot.dal.dataobject.product.IotProductDO;
+import com.viewsh.module.iot.dal.dataobject.subsystem.IotSubsystemDO;
+import com.viewsh.framework.mybatis.core.query.LambdaQueryWrapperX;
 import com.viewsh.module.iot.dal.mysql.device.IotDeviceMapper;
 import com.viewsh.module.iot.dal.redis.RedisKeyConstants;
+import com.viewsh.module.iot.dal.redis.subsystem.IotSubsystemDeviceCountRedisDAO;
 import com.viewsh.module.iot.enums.product.IotProductDeviceTypeEnum;
 import com.viewsh.module.iot.service.product.IotProductService;
+import com.viewsh.module.iot.service.subsystem.IotSubsystemService;
 import jakarta.annotation.Resource;
 import jakarta.validation.ConstraintViolationException;
 import lombok.extern.slf4j.Slf4j;
@@ -34,6 +39,8 @@ import org.springframework.cache.annotation.Caching;
 import org.springframework.context.annotation.Lazy;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
+import org.springframework.transaction.support.TransactionSynchronization;
+import org.springframework.transaction.support.TransactionSynchronizationManager;
 import org.springframework.validation.annotation.Validated;
 
 import javax.annotation.Nullable;
@@ -63,12 +70,25 @@ public class IotDeviceServiceImpl implements IotDeviceService {
     @Resource
     @Lazy // 延迟加载，解决循环依赖
     private IotDeviceGroupService deviceGroupService;
+    @Resource
+    @Lazy // 延迟加载，解决循环依赖（B11）
+    private IotSubsystemService subsystemService;
+
+    @Resource
+    private IotSubsystemDeviceCountRedisDAO subsystemDeviceCountRedisDAO;
 
     @Resource
     private IntegrationEventPublisher integrationEventPublisher;
 
     @Override
     public Long createDevice(IotDeviceSaveReqVO createReqVO) {
+        // 1.0 [B11] 校验 subsystemId 必填（新建强制，存量 NULL 兼容）
+        if (createReqVO.getSubsystemId() == null) {
+            throw exception(DEVICE_SUBSYSTEM_REQUIRED);
+        }
+        // 1.0.1 校验子系统存在且属于当前租户
+        validateSubsystemBelongsToCurrentTenant(createReqVO.getSubsystemId());
+
         // 1.1 校验产品是否存在
         IotProductDO product = productService.getProduct(createReqVO.getProductId());
         if (product == null) {
@@ -86,6 +106,10 @@ public class IotDeviceServiceImpl implements IotDeviceService {
         IotDeviceDO device = BeanUtils.toBean(createReqVO, IotDeviceDO.class);
         initDevice(device, product);
         deviceMapper.insert(device);
+
+        // 3. [B11] 同步 Redis 子系统设备计数 +1
+        subsystemDeviceCountRedisDAO.incrementCount(device.getTenantId(), createReqVO.getSubsystemId());
+
         return device.getId();
     }
 
@@ -406,6 +430,137 @@ public class IotDeviceServiceImpl implements IotDeviceService {
         return IdUtil.fastSimpleUUID();
     }
 
+    // ==================== B11：子系统绑定 ====================
+
+    /**
+     * 校验子系统存在且属于当前租户（跨租户绑定拒绝）
+     *
+     * @param subsystemId 子系统 ID
+     * @return 子系统 DO
+     */
+    private IotSubsystemDO validateSubsystemBelongsToCurrentTenant(Long subsystemId) {
+        IotSubsystemDO subsystem = subsystemService.getSubsystem(subsystemId);
+        if (subsystem == null) {
+            throw exception(SUBSYSTEM_NOT_EXISTS);
+        }
+        Long currentTenantId = TenantContextHolder.getTenantId();
+        if (!Objects.equals(subsystem.getTenantId(), currentTenantId)) {
+            throw exception(DEVICE_SUBSYSTEM_CROSS_TENANT);
+        }
+        return subsystem;
+    }
+
+    @Override
+    @Transactional(rollbackFor = Exception.class)
+    public void bindDeviceToSubsystem(Long deviceId, Long subsystemId) {
+        // 1. 校验设备存在
+        IotDeviceDO device = validateDeviceExists(deviceId);
+        Long oldSubsystemId = device.getSubsystemId();
+
+        // 2. 校验目标子系统存在且同租户
+        validateSubsystemBelongsToCurrentTenant(subsystemId);
+
+        // 3. 如果已绑定相同子系统，无需操作
+        if (Objects.equals(oldSubsystemId, subsystemId)) {
+            return;
+        }
+
+        // 4. 更新设备子系统
+        deviceMapper.updateById(new IotDeviceDO().setId(deviceId).setSubsystemId(subsystemId));
+
+        // 5. 事务提交后同步 Redis 计数（避免事务回滚导致计数脏）
+        Long tenantId = device.getTenantId();
+        Long finalOldSubsystemId = oldSubsystemId;
+        TransactionSynchronizationManager.registerSynchronization(new TransactionSynchronization() {
+            @Override
+            public void afterCommit() {
+                if (finalOldSubsystemId != null) {
+                    subsystemDeviceCountRedisDAO.decrementCount(tenantId, finalOldSubsystemId);
+                }
+                subsystemDeviceCountRedisDAO.incrementCount(tenantId, subsystemId);
+            }
+        });
+    }
+
+    @Override
+    @Transactional(rollbackFor = Exception.class)
+    public void batchBindDevicesToSubsystem(Collection<Long> deviceIds, Long subsystemId) {
+        if (CollUtil.isEmpty(deviceIds)) {
+            return;
+        }
+        // 1. 校验目标子系统存在且同租户
+        validateSubsystemBelongsToCurrentTenant(subsystemId);
+
+        // 2. 查询所有设备，统计旧子系统变化量
+        List<IotDeviceDO> devices = deviceMapper.selectByIds(deviceIds);
+        if (CollUtil.isEmpty(devices)) {
+            return;
+        }
+        Long tenantId = TenantContextHolder.getTenantId();
+
+        // 3. 统计旧子系统的减量（各子系统需减少的设备数）
+        Map<Long, Long> decrementMap = new HashMap<>();
+        for (IotDeviceDO device : devices) {
+            Long oldSubId = device.getSubsystemId();
+            if (oldSubId != null && !Objects.equals(oldSubId, subsystemId)) {
+                decrementMap.merge(oldSubId, 1L, Long::sum);
+            }
+        }
+        // 统计真正需要绑定的设备数（排除已是目标子系统的设备）
+        long incrementCount = devices.stream()
+                .filter(d -> !Objects.equals(d.getSubsystemId(), subsystemId))
+                .count();
+
+        // 4. 批量更新 DB
+        deviceMapper.updateSubsystemIdByIds(deviceIds, subsystemId);
+
+        // 5. 事务提交后批量更新 Redis 计数
+        TransactionSynchronizationManager.registerSynchronization(new TransactionSynchronization() {
+            @Override
+            public void afterCommit() {
+                // 旧子系统计数各自减少
+                decrementMap.forEach((oldSubId, count) -> {
+                    for (long i = 0; i < count; i++) {
+                        subsystemDeviceCountRedisDAO.decrementCount(tenantId, oldSubId);
+                    }
+                });
+                // 新子系统计数增加
+                for (long i = 0; i < incrementCount; i++) {
+                    subsystemDeviceCountRedisDAO.incrementCount(tenantId, subsystemId);
+                }
+            }
+        });
+    }
+
+    @Override
+    @Transactional(rollbackFor = Exception.class)
+    public void unbindDeviceFromSubsystem(Long deviceId) {
+        // 1. 校验设备存在
+        IotDeviceDO device = validateDeviceExists(deviceId);
+        Long oldSubsystemId = device.getSubsystemId();
+        if (oldSubsystemId == null) {
+            return; // 本来就未绑定，无需操作
+        }
+
+        // 2. 清空子系统
+        deviceMapper.updateById(new IotDeviceDO().setId(deviceId).setSubsystemId(null));
+
+        // 3. 事务提交后同步 Redis 计数
+        Long tenantId = device.getTenantId();
+        TransactionSynchronizationManager.registerSynchronization(new TransactionSynchronization() {
+            @Override
+            public void afterCommit() {
+                subsystemDeviceCountRedisDAO.decrementCount(tenantId, oldSubsystemId);
+            }
+        });
+    }
+
+    @Override
+    public List<IotDeviceDO> getUnassignedDevices() {
+        return deviceMapper.selectList(new LambdaQueryWrapperX<IotDeviceDO>()
+                .isNull(IotDeviceDO::getSubsystemId));
+    }
+
     @Override
     @Transactional(rollbackFor = Exception.class) // 添加事务，异常则回滚所有导入
     public IotDeviceImportRespVO importDevice(List<IotDeviceImportExcelVO> importDevices, boolean updateSupport) {

viewsh-module-iot/viewsh-module-iot-server/src/main/java/com/viewsh/module/iot/service/subsystem/IotSubsystemServiceImpl.java

@@ -3,22 +3,26 @@ package com.viewsh.module.iot.service.subsystem;
 import com.viewsh.framework.common.pojo.PageResult;
 import com.viewsh.framework.common.util.object.BeanUtils;
 import com.viewsh.framework.tenant.core.context.TenantContextHolder;
+import com.viewsh.framework.tenant.core.util.TenantUtils;
 import com.viewsh.module.iot.controller.admin.subsystem.vo.IotSubsystemDeviceStatsRespVO;
 import com.viewsh.module.iot.controller.admin.subsystem.vo.IotSubsystemPageReqVO;
 import com.viewsh.module.iot.controller.admin.subsystem.vo.IotSubsystemSaveReqVO;
 import com.viewsh.module.iot.controller.admin.subsystem.vo.IotSubsystemSimpleRespVO;
 import com.viewsh.module.iot.dal.dataobject.subsystem.IotSubsystemDO;
+import com.viewsh.module.iot.dal.mysql.device.IotDeviceMapper;
 import com.viewsh.module.iot.dal.mysql.subsystem.IotSubsystemMapper;
 import com.viewsh.module.iot.dal.redis.subsystem.IotSubsystemDeviceCountRedisDAO;
 import jakarta.annotation.Resource;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.boot.context.event.ApplicationReadyEvent;
+import org.springframework.context.annotation.Lazy;
 import org.springframework.context.event.EventListener;
 import org.springframework.stereotype.Service;
 import org.springframework.validation.annotation.Validated;
 
 import java.util.Collections;
 import java.util.List;
+import java.util.Map;
 import java.util.stream.Collectors;
 
 import static com.viewsh.framework.common.exception.util.ServiceExceptionUtil.exception;
@@ -37,6 +41,10 @@ public class IotSubsystemServiceImpl implements IotSubsystemService {
     @Resource
     private IotSubsystemMapper subsystemMapper;
 
+    @Resource
+    @Lazy // 延迟加载，避免与 IotDeviceServiceImpl 的循环依赖（B11）
+    private IotDeviceMapper deviceMapper;
+
     @Resource
     private IotSubsystemDeviceCountRedisDAO deviceCountRedisDAO;
 
@@ -97,10 +105,9 @@ public class IotSubsystemServiceImpl implements IotSubsystemService {
         IotSubsystemDO subsystem = validateSubsystemExists(id);
 
         // 2. 校验无设备（Known Pitfalls：有设备则拒绝）
-        // 注意：待 B11 加 subsystem_id 列后，下方逻辑调用 deviceMapper.selectCountBySubsystemId(id)
-        // 当前 iot_device 表尚无 subsystem_id 列，跳过 DB 校验，依赖 Redis 计数兜底
-        Long deviceCount = deviceCountRedisDAO.getCount(TenantContextHolder.getTenantId(), id);
-        if (deviceCount > 0) {
+        // [B11] iot_device.subsystem_id 已加列，使用 DB 真实计数
+        Long deviceCount = deviceMapper.selectCountBySubsystemId(id);
+        if (deviceCount != null && deviceCount > 0) {
             throw exception(SUBSYSTEM_HAS_DEVICES);
         }
 
@@ -181,9 +188,26 @@ public class IotSubsystemServiceImpl implements IotSubsystemService {
     @EventListener(ApplicationReadyEvent.class)
     public void rebuildDeviceCountCache() {
         try {
-            // TODO [B11] iot_device 尚无 subsystem_id 列，待 B11 加列后启用真正重建逻辑
-            // 当前为空实现，不阻塞启动
-            log.info("[rebuildDeviceCountCache] 子系统设备计数 Redis 重建跳过（待 B11 加列后启用）");
+            // [B11] iot_device.subsystem_id 已加列，从 DB 重建各子系统设备计数
+            // TenantIgnore：跨租户聚合查询，返回全量 subsystemId → count
+            // 注意：此处以全量方式重建，按 tenantId 分组调用 rebuild
+            Map<Long, Long> countMap = deviceMapper.selectCountGroupBySubsystemId();
+            if (countMap.isEmpty()) {
+                log.info("[rebuildDeviceCountCache] 无归属设备数据，跳过 Redis 重建");
+                return;
+            }
+            // 按子系统所属租户分别 rebuild（简单处理：批量写到单个 hash 时 rebuild 需 tenantId）
+            // 由于 selectCountGroupBySubsystemId 不含 tenantId，此处通过 getSubsystem 反查
+            // 性能已知：启动一次，可接受
+            countMap.forEach((subsystemId, count) -> {
+                IotSubsystemDO subsystem = subsystemMapper.selectById(subsystemId);
+                if (subsystem != null) {
+                    TenantUtils.execute(subsystem.getTenantId(), () ->
+                            deviceCountRedisDAO.rebuild(subsystem.getTenantId(),
+                                    Map.of(subsystemId, count)));
+                }
+            });
+            log.info("[rebuildDeviceCountCache] 子系统设备计数 Redis 重建完成，共 {} 条", countMap.size());
         } catch (Exception e) {
             // 启动时重建失败必须 try/catch + log.warn，不阻塞启动（Known Pitfalls）
             log.warn("[rebuildDeviceCountCache] 子系统设备计数重建失败，服务将继续启动，原因：{}", e.getMessage());

viewsh-module-iot/viewsh-module-iot-server/src/test/java/com/viewsh/module/iot/service/device/IotDeviceServiceImplTest.java

@@ -0,0 +1,263 @@
+package com.viewsh.module.iot.service.device;
+
+import com.viewsh.framework.common.exception.ServiceException;
+import com.viewsh.framework.mybatis.core.query.LambdaQueryWrapperX;
+import com.viewsh.framework.tenant.core.context.TenantContextHolder;
+import com.viewsh.module.iot.controller.admin.device.vo.device.IotDevicePageReqVO;
+import com.viewsh.module.iot.controller.admin.device.vo.device.IotDeviceSaveReqVO;
+import com.viewsh.module.iot.dal.dataobject.device.IotDeviceDO;
+import com.viewsh.module.iot.dal.dataobject.product.IotProductDO;
+import com.viewsh.module.iot.dal.dataobject.subsystem.IotSubsystemDO;
+import com.viewsh.module.iot.dal.mysql.device.IotDeviceMapper;
+import com.viewsh.module.iot.dal.redis.subsystem.IotSubsystemDeviceCountRedisDAO;
+import com.viewsh.module.iot.service.subsystem.IotSubsystemService;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.InjectMocks;
+import org.mockito.Mock;
+import org.mockito.MockedStatic;
+import org.mockito.junit.jupiter.MockitoExtension;
+import org.springframework.transaction.support.TransactionSynchronization;
+import org.springframework.transaction.support.TransactionSynchronizationManager;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
+
+import static com.viewsh.module.iot.enums.ErrorCodeConstants.*;
+import static org.junit.jupiter.api.Assertions.*;
+import static org.mockito.ArgumentMatchers.*;
+import static org.mockito.Mockito.*;
+
+/**
+ * {@link IotDeviceServiceImpl} 单元测试 — B11 子系统绑定相关
+ * <p>
+ * 覆盖任务卡 B11 §6 的 8 个用例。
+ * 不启 Spring 容器，全量 Mockito 驱动。
+ *
+ * @author B11
+ */
+@ExtendWith(MockitoExtension.class)
+class IotDeviceServiceImplTest {
+
+    @InjectMocks
+    private IotDeviceServiceImpl deviceService;
+
+    @Mock
+    private IotDeviceMapper deviceMapper;
+
+    @Mock
+    private IotSubsystemService subsystemService;
+
+    @Mock
+    private IotSubsystemDeviceCountRedisDAO subsystemDeviceCountRedisDAO;
+
+    private MockedStatic<TenantContextHolder> tenantContextHolderMock;
+    private MockedStatic<TransactionSynchronizationManager> txSyncManagerMock;
+
+    private static final Long TENANT_ID = 1L;
+    private static final Long SUBSYSTEM_ID_A = 100L;
+    private static final Long SUBSYSTEM_ID_B = 200L;
+    private static final Long DEVICE_ID = 999L;
+
+    @BeforeEach
+    void setUp() {
+        tenantContextHolderMock = mockStatic(TenantContextHolder.class);
+        tenantContextHolderMock.when(TenantContextHolder::getTenantId).thenReturn(TENANT_ID);
+
+        // TransactionSynchronizationManager.registerSynchronization 静态 mock：
+        // 立即执行 afterCommit 以便在测试中验证 Redis 调用
+        txSyncManagerMock = mockStatic(TransactionSynchronizationManager.class);
+        txSyncManagerMock.when(() -> TransactionSynchronizationManager.registerSynchronization(any(TransactionSynchronization.class)))
+                .thenAnswer(inv -> {
+                    TransactionSynchronization sync = inv.getArgument(0);
+                    sync.afterCommit();
+                    return null;
+                });
+    }
+
+    @AfterEach
+    void tearDown() {
+        tenantContextHolderMock.close();
+        txSyncManagerMock.close();
+    }
+
+    // ==================== 用例 1：新建设备不传 subsystemId → DEVICE_SUBSYSTEM_REQUIRED ====================
+
+    @Test
+    void testCreate_noSubsystem() {
+        IotDeviceSaveReqVO req = new IotDeviceSaveReqVO();
+        req.setProductId(1L);
+        // subsystemId 为 null
+
+        ServiceException ex = assertThrows(ServiceException.class, () -> deviceService.createDevice(req));
+        assertEquals(DEVICE_SUBSYSTEM_REQUIRED.getCode(), ex.getCode());
+
+        // 不应走到 mapper
+        verify(deviceMapper, never()).insert(any(IotDeviceDO.class));
+    }
+
+    // ==================== 用例 2：新建设备 subsystemId 不存在 → SUBSYSTEM_NOT_EXISTS ====================
+
+    @Test
+    void testCreate_invalidSubsystem() {
+        IotDeviceSaveReqVO req = new IotDeviceSaveReqVO();
+        req.setProductId(1L);
+        req.setSubsystemId(SUBSYSTEM_ID_A);
+
+        // subsystem 不存在
+        when(subsystemService.getSubsystem(SUBSYSTEM_ID_A)).thenReturn(null);
+
+        ServiceException ex = assertThrows(ServiceException.class, () -> deviceService.createDevice(req));
+        assertEquals(SUBSYSTEM_NOT_EXISTS.getCode(), ex.getCode());
+
+        verify(deviceMapper, never()).insert(any(IotDeviceDO.class));
+    }
+
+    // ==================== 用例 3：跨租户绑定 → DEVICE_SUBSYSTEM_CROSS_TENANT ====================
+
+    @Test
+    void testBind_crossTenant() {
+        // 设备存在
+        IotDeviceDO device = buildDevice(DEVICE_ID, TENANT_ID, null);
+        when(deviceMapper.selectById(DEVICE_ID)).thenReturn(device);
+
+        // 目标子系统属于租户 2（跨租户）
+        IotSubsystemDO subsystem = new IotSubsystemDO();
+        subsystem.setId(SUBSYSTEM_ID_A);
+        subsystem.setTenantId(2L); // 不同租户
+        when(subsystemService.getSubsystem(SUBSYSTEM_ID_A)).thenReturn(subsystem);
+
+        ServiceException ex = assertThrows(ServiceException.class,
+                () -> deviceService.bindDeviceToSubsystem(DEVICE_ID, SUBSYSTEM_ID_A));
+        assertEquals(DEVICE_SUBSYSTEM_CROSS_TENANT.getCode(), ex.getCode());
+
+        // Redis 计数不应变化
+        verify(subsystemDeviceCountRedisDAO, never()).incrementCount(any(), any());
+        verify(subsystemDeviceCountRedisDAO, never()).decrementCount(any(), any());
+    }
+
+    // ==================== 用例 4：单设备绑定新子系统 → Redis 计数同步 ====================
+
+    @Test
+    void testBind_single() {
+        // 设备原无子系统
+        IotDeviceDO device = buildDevice(DEVICE_ID, TENANT_ID, null);
+        when(deviceMapper.selectById(DEVICE_ID)).thenReturn(device);
+
+        // 目标子系统同租户
+        IotSubsystemDO subsystem = buildSubsystem(SUBSYSTEM_ID_A, TENANT_ID);
+        when(subsystemService.getSubsystem(SUBSYSTEM_ID_A)).thenReturn(subsystem);
+
+        deviceService.bindDeviceToSubsystem(DEVICE_ID, SUBSYSTEM_ID_A);
+
+        // 验证 DB 更新
+        verify(deviceMapper, times(1)).updateById(argThat((IotDeviceDO d) -> SUBSYSTEM_ID_A.equals(d.getSubsystemId())));
+        // 验证 Redis +1（无旧子系统，无 decrement）
+        verify(subsystemDeviceCountRedisDAO, times(1)).incrementCount(TENANT_ID, SUBSYSTEM_ID_A);
+        verify(subsystemDeviceCountRedisDAO, never()).decrementCount(any(), any());
+    }
+
+    // ==================== 用例 5：改绑（A → B）→ A -1 / B +1 ====================
+
+    @Test
+    void testBind_reassign() {
+        // 设备当前在子系统 A
+        IotDeviceDO device = buildDevice(DEVICE_ID, TENANT_ID, SUBSYSTEM_ID_A);
+        when(deviceMapper.selectById(DEVICE_ID)).thenReturn(device);
+
+        // 目标子系统 B 同租户
+        IotSubsystemDO subsystemB = buildSubsystem(SUBSYSTEM_ID_B, TENANT_ID);
+        when(subsystemService.getSubsystem(SUBSYSTEM_ID_B)).thenReturn(subsystemB);
+
+        deviceService.bindDeviceToSubsystem(DEVICE_ID, SUBSYSTEM_ID_B);
+
+        verify(deviceMapper, times(1)).updateById(argThat((IotDeviceDO d) -> SUBSYSTEM_ID_B.equals(d.getSubsystemId())));
+        verify(subsystemDeviceCountRedisDAO, times(1)).decrementCount(TENANT_ID, SUBSYSTEM_ID_A);
+        verify(subsystemDeviceCountRedisDAO, times(1)).incrementCount(TENANT_ID, SUBSYSTEM_ID_B);
+    }
+
+    // ==================== 用例 6：批量绑定 100 台 → Redis HINCRBY +100 ====================
+
+    @Test
+    void testBatchBind() {
+        int count = 100;
+        List<Long> deviceIds = new ArrayList<>();
+        List<IotDeviceDO> devices = new ArrayList<>();
+        for (long i = 1; i <= count; i++) {
+            deviceIds.add(i);
+            devices.add(buildDevice(i, TENANT_ID, null)); // 无旧子系统
+        }
+
+        when(deviceMapper.selectByIds(argThat(ids -> ids.size() == count))).thenReturn(devices);
+
+        // 目标子系统同租户
+        IotSubsystemDO subsystem = buildSubsystem(SUBSYSTEM_ID_A, TENANT_ID);
+        when(subsystemService.getSubsystem(SUBSYSTEM_ID_A)).thenReturn(subsystem);
+
+        deviceService.batchBindDevicesToSubsystem(deviceIds, SUBSYSTEM_ID_A);
+
+        // 验证批量 DB 更新
+        verify(deviceMapper, times(1)).updateSubsystemIdByIds(argThat(ids -> ids.size() == count), eq(SUBSYSTEM_ID_A));
+        // 验证 Redis incrementCount 被调用 100 次
+        verify(subsystemDeviceCountRedisDAO, times(count)).incrementCount(TENANT_ID, SUBSYSTEM_ID_A);
+        verify(subsystemDeviceCountRedisDAO, never()).decrementCount(any(), any());
+    }
+
+    // ==================== 用例 7：分页过滤 subsystemId ====================
+
+    @Test
+    void testPage_filterBySubsystem() {
+        IotDevicePageReqVO req = new IotDevicePageReqVO();
+        req.setSubsystemId(SUBSYSTEM_ID_A);
+        req.setPageNo(1);
+        req.setPageSize(10);
+
+        // 直接 mock 1-参数 default 方法
+        doReturn(new com.viewsh.framework.common.pojo.PageResult<>(List.of(), 0L))
+                .when(deviceMapper).selectPage(eq(req));
+
+        com.viewsh.framework.common.pojo.PageResult<IotDeviceDO> result = deviceService.getDevicePage(req);
+
+        assertNotNull(result);
+        // 验证 subsystemId 已传入 req（过滤条件在 Mapper 层 wrapper 中生效）
+        assertEquals(SUBSYSTEM_ID_A, req.getSubsystemId());
+        verify(deviceMapper, times(1)).selectPage(eq(req));
+    }
+
+    // ==================== 用例 8：未归属设备列表（subsystem_id IS NULL）====================
+
+    @Test
+    void testGetUnassigned() {
+        IotDeviceDO d1 = buildDevice(1L, TENANT_ID, null);
+        IotDeviceDO d2 = buildDevice(2L, TENANT_ID, null);
+        when(deviceMapper.selectList(any(LambdaQueryWrapperX.class))).thenReturn(Arrays.asList(d1, d2));
+
+        List<IotDeviceDO> result = deviceService.getUnassignedDevices();
+
+        assertNotNull(result);
+        assertEquals(2, result.size());
+        assertTrue(result.stream().allMatch(d -> d.getSubsystemId() == null));
+    }
+
+    // ==================== 辅助方法 ====================
+
+    private IotDeviceDO buildDevice(Long id, Long tenantId, Long subsystemId) {
+        IotDeviceDO device = new IotDeviceDO();
+        device.setId(id);
+        device.setTenantId(tenantId);
+        device.setSubsystemId(subsystemId);
+        return device;
+    }
+
+    private IotSubsystemDO buildSubsystem(Long id, Long tenantId) {
+        IotSubsystemDO subsystem = new IotSubsystemDO();
+        subsystem.setId(id);
+        subsystem.setTenantId(tenantId);
+        return subsystem;
+    }
+
+}

viewsh-module-iot/viewsh-module-iot-server/src/test/java/com/viewsh/module/iot/service/subsystem/IotSubsystemServiceImplTest.java

@@ -8,6 +8,7 @@ import com.viewsh.module.iot.controller.admin.subsystem.vo.IotSubsystemPageReqVO
 import com.viewsh.module.iot.controller.admin.subsystem.vo.IotSubsystemSaveReqVO;
 import com.viewsh.module.iot.controller.admin.subsystem.vo.IotSubsystemSimpleRespVO;
 import com.viewsh.module.iot.dal.dataobject.subsystem.IotSubsystemDO;
+import com.viewsh.module.iot.dal.mysql.device.IotDeviceMapper;
 import com.viewsh.module.iot.dal.mysql.subsystem.IotSubsystemMapper;
 import com.viewsh.module.iot.dal.redis.subsystem.IotSubsystemDeviceCountRedisDAO;
 import org.junit.jupiter.api.AfterEach;
@@ -46,6 +47,9 @@ class IotSubsystemServiceImplTest {
     @Mock
     private IotSubsystemDeviceCountRedisDAO deviceCountRedisDAO;
 
+    @Mock
+    private IotDeviceMapper deviceMapper;
+
     private MockedStatic<TenantContextHolder> tenantContextHolderMock;
 
     private static final Long TENANT_ID = 1L;
@@ -188,8 +192,8 @@ class IotSubsystemServiceImplTest {
         sub.setTenantId(TENANT_ID);
         when(subsystemMapper.selectById(subsystemId)).thenReturn(sub);
 
-        // Redis 显示有设备
-        when(deviceCountRedisDAO.getCount(TENANT_ID, subsystemId)).thenReturn(5L);
+        // [B11] DB 显示有设备（使用 device mapper 真实计数）
+        when(deviceMapper.selectCountBySubsystemId(subsystemId)).thenReturn(5L);
 
         // 执行 → 应抛出 SUBSYSTEM_HAS_DEVICES
         ServiceException ex = assertThrows(ServiceException.class, () -> subsystemService.deleteSubsystem(subsystemId));
@@ -210,8 +214,8 @@ class IotSubsystemServiceImplTest {
         sub.setTenantId(TENANT_ID);
         when(subsystemMapper.selectById(subsystemId)).thenReturn(sub);
 
-        // Redis 显示无设备
-        when(deviceCountRedisDAO.getCount(TENANT_ID, subsystemId)).thenReturn(0L);
+        // [B11] DB 显示无设备
+        when(deviceMapper.selectCountBySubsystemId(subsystemId)).thenReturn(0L);
 
         // 执行 → 不抛异常
         assertDoesNotThrow(() -> subsystemService.deleteSubsystem(subsystemId));

viewsh-module-iot/viewsh-module-iot-server/src/test/resources/sql/create_tables.sql

@@ -52,6 +52,7 @@ CREATE TABLE IF NOT EXISTS "iot_device" (
     "device_type" tinyint NOT NULL DEFAULT '0',
     "gateway_id" bigint DEFAULT NULL,
     "sub_device_count" int NOT NULL DEFAULT '0',
+    "subsystem_id" bigint DEFAULT NULL,
     "creator" varchar(64) DEFAULT '',
     "create_time" timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
     "updater" varchar(64) DEFAULT '',