fix(explore): formatting the SQL in "View Query" pop-up doesn't format (#35898)

Co-authored-by: Claude <noreply@anthropic.com>

superset-frontend/src/explore/components/controls/ViewQuery.test.tsx

@@ -265,3 +265,29 @@ test('uses exploreBackend from Redux state when available', async () => {
   expect(formatCallBody.engine).toBe('postgresql');
   expect(fetchMock.calls(datasetApiEndpoint)).toHaveLength(0);
 });
+
+test('sends engine as string (not object) when fetched from dataset API', async () => {
+  const stateWithoutBackend = {
+    ...mockState(),
+    explore: undefined,
+  };
+
+  setup(mockProps, stateWithoutBackend);
+
+  await waitFor(() => {
+    expect(fetchMock.calls(datasetApiEndpoint)).toHaveLength(1);
+  });
+
+  await waitFor(() => {
+    expect(fetchMock.calls(formatSqlEndpoint)).toHaveLength(1);
+  });
+
+  const formatCallBody = JSON.parse(
+    fetchMock.lastCall(formatSqlEndpoint)?.[1]?.body as string,
+  );
+
+  expect(formatCallBody).toEqual({
+    sql: mockProps.sql,
+    engine: 'sqlite',
+  });
+});

superset-frontend/src/explore/components/controls/ViewQuery.tsx

@@ -106,7 +106,8 @@ const ViewQuery: FC<ViewQueryProps> = props => {
         const response = await SupersetClient.get({
           endpoint: `/api/v1/dataset/${datasetId}?q=${queryParams}`,
         });
-        backend = response.json.result.database;
+        const { backend: datasetBackend } = response.json.result.database;
+        backend = datasetBackend;
       }
 
       // Format the SQL query