master：app分类排除掉最顶层商品分类；

ruoyi-common/src/main/java/com/ruoyi/common/constant/Constants.java

@@ -237,6 +237,8 @@ public class Constants
     public static final String VOUCHER_SEQ_STORE_ORDER_TYPE = "STORE_ORDER";
     // %04d
     public static final String VOUCHER_SEQ_FORMAT = "%04d";
+    // 商品分类最顶层parentId
+    public static final Long CATE_TOP_PARENT_ID = 0L;
 
     /**
      * 上市季节年份

xkt/src/main/java/com/ruoyi/xkt/service/impl/SysProductCategoryServiceImpl.java

@@ -127,6 +127,8 @@ public class SysProductCategoryServiceImpl implements ISysProductCategoryService
     public List<ProdCateListResDTO> selectList(ProdCateListDTO listDTO) {
         LambdaQueryWrapper<SysProductCategory> queryWrapper = new LambdaQueryWrapper<SysProductCategory>()
                 .eq(SysProductCategory::getDelFlag, Constants.UNDELETED)
+                // 排除掉最顶层商品分类
+                .ne(SysProductCategory::getParentId, Constants.CATE_TOP_PARENT_ID)
                 .orderByAsc(Arrays.asList(SysProductCategory::getOrderNum, SysProductCategory::getId));
         if (StringUtils.isNotBlank(listDTO.getName())) {
             queryWrapper.like(SysProductCategory::getName, listDTO.getName());