PanelQueryRunner: add datasource name to queries (#16712)

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

@@ -133,6 +133,14 @@ export class PanelQueryRunner {
           ? (datasource as DataSourceApi)
           : await getDatasourceSrv().get(datasource as string, request.scopedVars);
 
+      // Attach the datasource name to each query
+      request.targets = request.targets.map(query => {
+        if (!query.datasource) {
+          query.datasource = ds.name;
+        }
+        return query;
+      });
+
       const lowerIntervalLimit = minInterval ? templateSrv.replace(minInterval, request.scopedVars) : ds.interval;
       const norm = kbn.calculateInterval(timeRange, widthPixels, lowerIntervalLimit);