diff --git a/frontend/src/components/QueryEditor.external-sql-save.test.tsx b/frontend/src/components/QueryEditor.external-sql-save.test.tsx
index 99963ff..2548ee1 100644
--- a/frontend/src/components/QueryEditor.external-sql-save.test.tsx
+++ b/frontend/src/components/QueryEditor.external-sql-save.test.tsx
@@ -522,8 +522,20 @@ describe('QueryEditor external SQL save', () => {
     backendApp.DBGetDatabases.mockResolvedValue({ success: true, data: [] });
     backendApp.DBGetTables.mockResolvedValue({ success: true, data: [] });
     backendApp.GenerateQueryID.mockResolvedValue('query-1');
-    storeState.connections[0].config.type = 'mysql';
-    storeState.connections[0].config.database = 'main';
+    storeState.connections = [
+      {
+        id: 'conn-1',
+        name: 'local',
+        config: {
+          type: 'mysql',
+          host: '127.0.0.1',
+          port: 3306,
+          user: 'root',
+          password: '',
+          database: 'main',
+        },
+      },
+    ];
     storeState.appearance.uiVersion = 'legacy';
     autoFetchState.visible = false;
     dataGridState.latestProps = null;
@@ -1508,6 +1520,79 @@ describe('QueryEditor external SQL save', () => {
     );
   });
 
+  it('formats postgres cast syntax after switching to another query tab connection', async () => {
+    let renderer!: ReactTestRenderer;
+    storeState.connections = [
+      {
+        id: 'conn-1',
+        name: 'mysql-local',
+        config: {
+          type: 'mysql',
+          host: '127.0.0.1',
+          port: 3306,
+          user: 'root',
+          password: '',
+          database: 'main',
+        },
+      },
+      {
+        id: 'conn-2',
+        name: 'pg-local',
+        config: {
+          type: 'postgres',
+          host: '127.0.0.1',
+          port: 5432,
+          user: 'postgres',
+          password: '',
+          database: 'main',
+        },
+      },
+    ];
+    const pgSql = [
+      'SELECT',
+      '    *,',
+      '    is_del = 0',
+      'FROM',
+      '    wm_stock',
+      'WHERE',
+      '    1 = 1',
+      '    AND is_del = 0',
+      "    and create_date > '2025-06-25'::date;",
+    ].join('\n');
+
+    await act(async () => {
+      renderer = create(<QueryEditor tab={createTab({ id: 'tab-1', connectionId: 'conn-1', query: 'select 1;' })} />);
+    });
+
+    await act(async () => {
+      renderer.update(
+        <QueryEditor
+          tab={createTab({
+            id: 'tab-2',
+            connectionId: 'conn-2',
+            dbName: 'main',
+            query: pgSql,
+          })}
+        />,
+      );
+    });
+
+    const formatButton = findButton(renderer, '美化');
+    await act(async () => {
+      await formatButton.props.onClick();
+    });
+
+    expect(messageApi.error).not.toHaveBeenCalled();
+    expect(editorState.editor.executeEdits).toHaveBeenCalledWith(
+      'gonavi-format-sql',
+      expect.arrayContaining([
+        expect.objectContaining({
+          text: expect.stringContaining("'2025-06-25'::date;"),
+        }),
+      ]),
+    );
+  });
+
   it('shows object info via editor ctrl+q action', async () => {
     editorState.value = 'select users.id from users';
     autoFetchState.visible = true;
diff --git a/frontend/src/components/QueryEditor.tsx b/frontend/src/components/QueryEditor.tsx
index 7385696..c2dac12 100644
--- a/frontend/src/components/QueryEditor.tsx
+++ b/frontend/src/components/QueryEditor.tsx
@@ -2047,6 +2047,19 @@ const QueryEditor: React.FC<{ tab: TabData; isActive?: boolean }> = ({ tab, isAc
       currentDbRef.current = currentDb;
   }, [currentDb]);
 
+  useEffect(() => {
+      const nextConnectionId = String(tab.connectionId || '').trim();
+      const nextDb = String(tab.dbName || '').trim();
+      if (nextConnectionId !== currentConnectionIdRef.current) {
+          currentConnectionIdRef.current = nextConnectionId;
+          setCurrentConnectionId(nextConnectionId);
+      }
+      if (nextDb !== currentDbRef.current) {
+          currentDbRef.current = nextDb;
+          setCurrentDb(nextDb);
+      }
+  }, [tab.id, tab.connectionId, tab.dbName]);
+
   useEffect(() => {
       if (isExternalSQLFileTab) return;
       const currentDraft = getQueryTabDraft(tab.id, query);
@@ -3704,7 +3717,13 @@ const QueryEditor: React.FC<{ tab: TabData; isActive?: boolean }> = ({ tab, isAc
 
   const handleFormat = () => {
       try {
-          const formatterLanguage = resolveQueryEditorFormatterLanguage(connections.find(c => c.id === currentConnectionId));
+          const activeConnectionId = String(currentConnectionIdRef.current || '').trim();
+          const tabConnectionId = String(tab.connectionId || '').trim();
+          const conn = connectionsRef.current.find(c => c.id === activeConnectionId)
+              || (tabConnectionId && tabConnectionId !== activeConnectionId
+                  ? connectionsRef.current.find(c => c.id === tabConnectionId)
+                  : undefined);
+          const formatterLanguage = resolveQueryEditorFormatterLanguage(conn);
           const formatted = format(getCurrentQuery(), { language: formatterLanguage, keywordCase: sqlFormatOptions.keywordCase });
           const editor = editorRef.current;
           const monaco = monacoRef.current;