diff --git a/frontend/package.json.md5 b/frontend/package.json.md5
index b8be944..ad6ce0c 100755
--- a/frontend/package.json.md5
+++ b/frontend/package.json.md5
@@ -1 +1 @@
-f697e821b4acd5cf614d63d46453e8a4
\ No newline at end of file
+20168ff7047e0ecea00acb73f413f7db
\ No newline at end of file
diff --git a/frontend/src/components/RedisMonitor.tsx b/frontend/src/components/RedisMonitor.tsx
index 95000ea..0e5cc25 100644
--- a/frontend/src/components/RedisMonitor.tsx
+++ b/frontend/src/components/RedisMonitor.tsx
@@ -51,7 +51,7 @@ const RedisMonitor: React.FC<RedisMonitorProps> = ({ connectionId, redisDB }) =>
   // Ref to track if component is mounted to prevent state updates after unmount
   const mountedRef = useRef(true);
   // Interval ref
-  const intervalRef = useRef<NodeJS.Timeout | null>(null);
+  const intervalRef = useRef<ReturnType<typeof setInterval> | null>(null);
   // Previous ops counter to calculate QPS if instantaneous_ops_per_sec is not enough
   const prevMetricsRef = useRef({ prevOps: 0, prevTime: 0 });
 
diff --git a/frontend/src/components/Sidebar.tsx b/frontend/src/components/Sidebar.tsx
index 64a0232..58658f3 100644
--- a/frontend/src/components/Sidebar.tsx
+++ b/frontend/src/components/Sidebar.tsx
@@ -1036,13 +1036,21 @@ const Sidebar: React.FC<{ onEditConnection?: (conn: SavedConnection) => void }>
                 dbs = dbs.filter(db => conn.includeDatabases!.includes(db.title));
             }
 
-            setTreeData(origin => updateTreeData(origin, node.key, dbs));
+            if (dbs.length > 0) {
+                setTreeData(origin => updateTreeData(origin, node.key, dbs));
+            } else {
+                // 空列表：清理 loadedKeys 以允许重新加载，不设置 children = []
+                setLoadedKeys(prev => prev.filter(k => k !== node.key));
+                message.warning({ content: '未获取到可见数据库/schema，请检查账号权限或右键刷新', key: `conn-${conn.id}-dbs` });
+            }
 	          } else {
 	            setConnectionStates(prev => ({ ...prev, [conn.id]: 'error' }));
+	            setLoadedKeys(prev => prev.filter(k => k !== node.key));
 	            message.error({ content: res.message, key: `conn-${conn.id}-dbs` });
 	          }
 	      } catch (e: any) {
 	          setConnectionStates(prev => ({ ...prev, [conn.id]: 'error' }));
+	          setLoadedKeys(prev => prev.filter(k => k !== node.key));
 	          message.error({ content: '连接失败: ' + (e?.message || String(e)), key: `conn-${conn.id}-dbs` });
 	      } finally {
 	          loadingNodesRef.current.delete(loadKey);
diff --git a/internal/db/dameng_metadata.go b/internal/db/dameng_metadata.go
index b0f698b..15d12ad 100644
--- a/internal/db/dameng_metadata.go
+++ b/internal/db/dameng_metadata.go
@@ -9,9 +9,9 @@ import (
 )
 
 var damengDatabaseQueries = []string{
-	// 优先使用达梦原生系统表
-	"SELECT DISTINCT OBJECT_NAME AS DATABASE_NAME FROM SYS.SYSOBJECTS WHERE TYPE$ = 'SCH' AND OBJECT_NAME NOT IN ('SYS','SYSDBA','SYSAUDITOR','SYSSSO','CTISYS','__RECYCLE_USER__') ORDER BY OBJECT_NAME",
-	"SELECT SCHEMA_NAME AS DATABASE_NAME FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME NOT IN ('SYS','SYSDBA','SYSAUDITOR','SYSSSO','CTISYS','INFORMATION_SCHEMA') ORDER BY SCHEMA_NAME",
+	// 优先使用达梦原生系统表（SYSDBA 保留：作为默认管理员 schema，大多数用户在此创建业务表）
+	"SELECT DISTINCT OBJECT_NAME AS DATABASE_NAME FROM SYS.SYSOBJECTS WHERE TYPE$ = 'SCH' AND OBJECT_NAME NOT IN ('SYS','SYSAUDITOR','SYSSSO','CTISYS','__RECYCLE_USER__') ORDER BY OBJECT_NAME",
+	"SELECT SCHEMA_NAME AS DATABASE_NAME FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME NOT IN ('SYS','SYSAUDITOR','SYSSSO','CTISYS','INFORMATION_SCHEMA') ORDER BY SCHEMA_NAME",
 	// Oracle 兼容层
 	"SELECT SYS_CONTEXT('USERENV', 'CURRENT_SCHEMA') AS DATABASE_NAME FROM DUAL",
 	"SELECT SYS_CONTEXT('USERENV', 'CURRENT_USER') AS DATABASE_NAME FROM DUAL",
@@ -21,6 +21,8 @@ var damengDatabaseQueries = []string{
 	"SELECT USERNAME AS DATABASE_NAME FROM SYS.DBA_USERS ORDER BY USERNAME",
 	"SELECT DISTINCT OWNER AS DATABASE_NAME FROM ALL_OBJECTS ORDER BY OWNER",
 	"SELECT DISTINCT OWNER AS DATABASE_NAME FROM ALL_TABLES ORDER BY OWNER",
+	// 最终兜底：获取当前连接用户作为 schema 名称
+	"SELECT USER AS DATABASE_NAME FROM DUAL",
 }
 
 type damengQueryFunc func(query string) ([]map[string]interface{}, []string, error)
diff --git a/internal/db/dameng_metadata_test.go b/internal/db/dameng_metadata_test.go
index 5310679..b5b6557 100644
--- a/internal/db/dameng_metadata_test.go
+++ b/internal/db/dameng_metadata_test.go
@@ -71,3 +71,50 @@ func TestCollectDamengDatabaseNames_ReturnsErrorWhenNoNameResolved(t *testing.T)
 		t.Fatalf("错误不符合预期: %v", err)
 	}
 }
+
+// TestCollectDamengDatabaseNames_IncludesSYSDBA 验证 SYSDBA（达梦默认管理员 schema）
+// 不会被系统 schema 过滤排除。
+func TestCollectDamengDatabaseNames_IncludesSYSDBA(t *testing.T) {
+	t.Parallel()
+
+	got, err := collectDamengDatabaseNames(func(query string) ([]map[string]interface{}, []string, error) {
+		switch query {
+		case damengDatabaseQueries[0]:
+			// 查询 0 返回 SYSDBA（之前会被排除，修复后应该返回）
+			return []map[string]interface{}{{"DATABASE_NAME": "SYSDBA"}}, nil, nil
+		default:
+			return nil, nil, errors.New("permission denied")
+		}
+	})
+	if err != nil {
+		t.Fatalf("collectDamengDatabaseNames 返回错误: %v", err)
+	}
+
+	want := []string{"SYSDBA"}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("SYSDBA 应该包含在结果中, got=%v want=%v", got, want)
+	}
+}
+
+// TestCollectDamengDatabaseNames_FallbackToCurrentUser 验证当所有查询都失败时
+// 兜底查询 SELECT USER FROM DUAL 能返回当前用户作为 schema。
+func TestCollectDamengDatabaseNames_FallbackToCurrentUser(t *testing.T) {
+	t.Parallel()
+
+	lastQuery := damengDatabaseQueries[len(damengDatabaseQueries)-1]
+	got, err := collectDamengDatabaseNames(func(query string) ([]map[string]interface{}, []string, error) {
+		if query == lastQuery {
+			return []map[string]interface{}{{"DATABASE_NAME": "SYSDBA"}}, nil, nil
+		}
+		// 前面所有查询要么返回空要么报错
+		return []map[string]interface{}{}, nil, nil
+	})
+	if err != nil {
+		t.Fatalf("collectDamengDatabaseNames 返回错误: %v", err)
+	}
+
+	want := []string{"SYSDBA"}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("兜底查询应该返回当前用户, got=%v want=%v", got, want)
+	}
+}