Special case mixed datasources... :/

public/app/features/query/components/QueryEditorRows.tsx

@@ -149,7 +149,7 @@ const getDataSourceSettings = (
   query: DataQuery,
   groupSettings: DataSourceInstanceSettings
 ): DataSourceInstanceSettings => {
-  if (!query.datasource) {
+  if (!query.datasource && !groupSettings.meta.mixed) {
     return groupSettings;
   }
   const querySettings = getDataSourceSrv().getInstanceSettings(query.datasource);

public/app/features/query/state/PanelQueryRunner.test.ts

@@ -92,7 +92,9 @@ function describeQueryRunnerScenario(
       ],
     };
 
-    setDataSourceSrv({} as any);
+    setDataSourceSrv({
+      get: jest.fn(),
+    } as any);
     setDashboardQueryRunnerFactory(() => ({
       getResult: emptyResult,
       run: () => undefined,

public/app/features/query/state/PanelQueryRunner.ts

@@ -230,11 +230,12 @@ export class PanelQueryRunner {
 
     try {
       const ds = await getDataSource(datasource, request.scopedVars);
+      const defaultDatasource = await getDataSource(null, request.scopedVars);
 
       // Attach the data source name to each query
       request.targets = request.targets.map((query) => {
         if (!query.datasource) {
-          query.datasource = ds.getRef();
+          query.datasource = ds.meta?.mixed ? defaultDatasource.getRef() : ds.getRef();
         }
         return query;
       });