fix: 学校列表创建人显示昵称而不是ID

注入 UserService，批量查询创建人昵称并映射到树形节点

backend/ruoyi-modules/pangu-business/src/main/java/org/dromara/pangu/school/service/impl/PgSchoolServiceImpl.java

@@ -20,6 +20,7 @@ import org.dromara.pangu.school.mapper.PgSchoolClassMapper;
 import org.dromara.pangu.school.mapper.PgSchoolGradeMapper;
 import org.dromara.pangu.school.mapper.PgSchoolMapper;
 import org.dromara.pangu.school.service.IPgSchoolService;
+import org.dromara.common.core.service.UserService;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
@@ -42,6 +43,7 @@ public class PgSchoolServiceImpl implements IPgSchoolService {
     private final PgGradeMapper gradeMapper;
     private final PgClassMapper classMapper;
     private final PgRegionMapper regionMapper;
+    private final UserService userService;
 
     @Override
     public TableDataInfo<PgSchool> selectPageList(PgSchool school, PageQuery pageQuery) {
@@ -281,9 +283,20 @@ public class PgSchoolServiceImpl implements IPgSchoolService {
             classNameMap = classes.stream().collect(java.util.stream.Collectors.toMap(PgClass::getClassId, PgClass::getClassName));
         }
 
+        // 批量查询创建人昵称
+        Set<Long> createByIds = schools.stream()
+            .map(PgSchool::getCreateBy)
+            .filter(id -> id != null)
+            .collect(Collectors.toSet());
+        Map<Long, String> userNicknameMap = new HashMap<>();
+        if (!createByIds.isEmpty()) {
+            userNicknameMap = userService.selectUserNamesByIds(new ArrayList<>(createByIds));
+        }
+
         // 构建树形结构
         SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
         List<SchoolTreeNode> result = new ArrayList<>();
+        Map<Long, String> finalUserNicknameMap = userNicknameMap;
 
         for (PgSchool s : schools) {
             SchoolTreeNode schoolNode = new SchoolTreeNode();
@@ -296,7 +309,8 @@ public class PgSchoolServiceImpl implements IPgSchoolService {
             schoolNode.setRegionId(s.getRegionId());
             schoolNode.setStatus(s.getStatus());
             schoolNode.setCreateTime(s.getCreateTime() != null ? sdf.format(s.getCreateTime()) : null);
-            schoolNode.setCreateBy(s.getCreateBy() != null ? s.getCreateBy().toString() : null);
+            // 使用昵称而不是ID
+            schoolNode.setCreateBy(s.getCreateBy() != null ? finalUserNicknameMap.getOrDefault(s.getCreateBy(), s.getCreateBy().toString()) : null);
             schoolNode.setSchoolId(s.getSchoolId());
 
             // 查找该学校的年级