diff --git a/apps/desktop/src/components/sidebar/TreeItem.vue b/apps/desktop/src/components/sidebar/TreeItem.vue
index 5cfa10fba..57939afac 100644
--- a/apps/desktop/src/components/sidebar/TreeItem.vue
+++ b/apps/desktop/src/components/sidebar/TreeItem.vue
@@ -80,6 +80,7 @@ import { copyNameForTreeNode, objectSourceKindForTreeNode, sidebarSelectionCopyA
 import { formatSqlInsert } from "@/lib/exportFormats";
 import { joinExportedDdls } from "@/lib/ddlExport";
 import { fetchTableDataForExport } from "@/lib/tableDataExport";
+import { canActivateExistingDataTableTab } from "@/lib/dataTabActivation";
 import { buildCreateDatabaseSql, buildDuckDbAttachDatabaseSql, duckDbAttachedDatabaseNameFromPath, supportsCreateDatabaseCharset, uniqueDuckDbAttachedDatabaseName } from "@/lib/createDatabaseSql";
 import {
   buildCreateSchemaSql,
@@ -951,12 +952,7 @@ async function openData() {
   const tableSchema = connectionObjectTreeNodeSchema(config, node.database, node.schema);
   const tableType = node.type === "view" ? "VIEW" : node.type === "materialized_view" ? "MATERIALIZED_VIEW" : (node.tableType ?? "TABLE");
   const isSameDataTableTab = (tab: (typeof queryStore.tabs)[number]) => tab.mode === "data" && tab.connectionId === node.connectionId && tab.database === node.database && (tab.schema || "") === (tableSchema || "") && (tab.tableMeta?.tableName || tab.title) === node.label;
-  const activateExistingSameTableTab = () => {
-    const existing = queryStore.tabs.find(isSameDataTableTab);
-    if (!existing) return false;
-    queryStore.activeTabId = existing.id;
-    return true;
-  };
+  const existingSameTableTab = queryStore.tabs.find(isSameDataTableTab);
   const resetReusedDataTabState = (tab: (typeof queryStore.tabs)[number]) => {
     tab.title = node.label;
     tab.schema = tableSchema;
@@ -979,12 +975,18 @@ async function openData() {
     tab.queryEditabilityReason = undefined;
   };
 
-  if (activateExistingSameTableTab()) {
+  if (existingSameTableTab && canActivateExistingDataTableTab(existingSameTableTab)) {
+    queryStore.activeTabId = existingSameTableTab.id;
     logPhase("existing-tab-activated", { table: node.label });
     return;
   }
 
   const tabId = (() => {
+    if (existingSameTableTab) {
+      queryStore.activeTabId = existingSameTableTab.id;
+      resetReusedDataTabState(existingSameTableTab);
+      return existingSameTableTab.id;
+    }
     if (settingsStore.editorSettings.reuseDataTab) {
       const existing = queryStore.tabs.find((tab) => tab.mode === "data" && tab.connectionId === node.connectionId && tab.database === node.database);
       if (existing) {
diff --git a/apps/desktop/src/lib/connectionHealth.ts b/apps/desktop/src/lib/connectionHealth.ts
index 57527c7c7..74576c329 100644
--- a/apps/desktop/src/lib/connectionHealth.ts
+++ b/apps/desktop/src/lib/connectionHealth.ts
@@ -21,9 +21,11 @@ const CONNECTION_ERROR_PATTERNS = [
   "agent stdout not available",
   "failed to write to agent stdin",
   "failed to flush agent stdin",
+  "input/output error",
   "关闭的连接",
   "连接已关闭",
   "i/o error",
+  "no route to host",
 ];
 
 export function staleConnectionMessage(error: unknown): string {
@@ -37,7 +39,7 @@ export function shouldMarkDisconnected(error: unknown): boolean {
 }
 
 function hasConnectionOsError(message: string): boolean {
-  const osErrorCodes = new Set(["10053", "10054", "10057", "10058", "10060", "10061"]);
+  const osErrorCodes = new Set(["65", "10053", "10054", "10057", "10058", "10060", "10061"]);
   const match = message.match(/os error\s+(\d+)/);
   return !!match && osErrorCodes.has(match[1]);
 }
diff --git a/apps/desktop/src/lib/dataTabActivation.ts b/apps/desktop/src/lib/dataTabActivation.ts
new file mode 100644
index 000000000..7ab657ea3
--- /dev/null
+++ b/apps/desktop/src/lib/dataTabActivation.ts
@@ -0,0 +1,11 @@
+import type { QueryResult, QueryTab } from "@/types/database";
+
+function isErrorResult(result: QueryResult | undefined): boolean {
+  return result?.columns.length === 1 && result.columns[0] === "Error";
+}
+
+export function canActivateExistingDataTableTab(tab: QueryTab): boolean {
+  if (tab.isExecuting) return true;
+  if (isErrorResult(tab.result)) return false;
+  return !!tab.result || !!tab.results?.length;
+}
diff --git a/packages/app-tests/connectionStoreErrorState.test.ts b/packages/app-tests/connectionStoreErrorState.test.ts
index 88b28ce12..e8be78188 100644
--- a/packages/app-tests/connectionStoreErrorState.test.ts
+++ b/packages/app-tests/connectionStoreErrorState.test.ts
@@ -161,6 +161,7 @@ test("known backend connection errors mark the connection disconnected", async (
     "ORA-02396: exceeded maximum idle time, please connect again",
     "Agent stdin not available",
     "Failed to write to agent stdin",
+    "MySQL connection failed: Input/output error: No route to host (os error 65)",
   ];
 
   try {
diff --git a/packages/app-tests/dataTabActivation.test.ts b/packages/app-tests/dataTabActivation.test.ts
new file mode 100644
index 000000000..c1b6a5fc8
--- /dev/null
+++ b/packages/app-tests/dataTabActivation.test.ts
@@ -0,0 +1,59 @@
+import { strict as assert } from "node:assert";
+import { test } from "vitest";
+import { canActivateExistingDataTableTab } from "../../apps/desktop/src/lib/dataTabActivation.ts";
+import type { QueryTab } from "../../apps/desktop/src/types/database.ts";
+
+function dataTab(overrides: Partial<QueryTab> = {}): QueryTab {
+  return {
+    id: "tab-1",
+    title: "users",
+    connectionId: "conn-1",
+    database: "app",
+    sql: "select * from users",
+    isExecuting: false,
+    isCancelling: false,
+    isExplaining: false,
+    mode: "data",
+    ...overrides,
+  };
+}
+
+test("activates an existing data table tab while it is still loading", () => {
+  assert.equal(canActivateExistingDataTableTab(dataTab({ isExecuting: true })), true);
+});
+
+test("activates an existing data table tab with a usable result", () => {
+  assert.equal(
+    canActivateExistingDataTableTab(
+      dataTab({
+        result: {
+          columns: ["id"],
+          rows: [[1]],
+          affected_rows: 0,
+          execution_time_ms: 1,
+        },
+      }),
+    ),
+    true,
+  );
+});
+
+test("reloads restored data table tabs without a result", () => {
+  assert.equal(canActivateExistingDataTableTab(dataTab()), false);
+});
+
+test("reloads existing data table tabs showing an error result", () => {
+  assert.equal(
+    canActivateExistingDataTableTab(
+      dataTab({
+        result: {
+          columns: ["Error"],
+          rows: [["MySQL connection failed: Input/output error: No route to host (os error 65)"]],
+          affected_rows: 0,
+          execution_time_ms: 0,
+        },
+      }),
+    ),
+    false,
+  );
+});