From 921cbc77be0fce6b8464af79e74b17b4d23238dc Mon Sep 17 00:00:00 2001
From: Ihor Yeromin <yeryomin.igor@gmail.com>
Date: Wed, 9 Jul 2025 16:33:36 +0200
Subject: [PATCH 1/2] feat(transformations): allow groupBy aggregation

---
 .../src/transformations/transformers/groupBy.ts        |  6 +-----
 .../transformers/editors/GroupByTransformerEditor.tsx  | 10 +++-------
 2 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/packages/grafana-data/src/transformations/transformers/groupBy.ts b/packages/grafana-data/src/transformations/transformers/groupBy.ts
index f00219a5657..8048c17faa7 100644
--- a/packages/grafana-data/src/transformations/transformers/groupBy.ts
+++ b/packages/grafana-data/src/transformations/transformers/groupBy.ts
@@ -146,11 +146,7 @@ export const groupByTransformer: DataTransformerInfo<GroupByTransformerOptions>
 
 const shouldCalculateField = (field: Field, options: GroupByTransformerOptions): boolean => {
   const fieldName = getFieldDisplayName(field);
-  return (
-    options?.fields[fieldName]?.operation === GroupByOperationID.aggregate &&
-    Array.isArray(options?.fields[fieldName].aggregations) &&
-    options?.fields[fieldName].aggregations.length > 0
-  );
+  return Array.isArray(options?.fields[fieldName]?.aggregations) && options?.fields[fieldName].aggregations.length > 0;
 };
 
 /**
diff --git a/public/app/features/transformers/editors/GroupByTransformerEditor.tsx b/public/app/features/transformers/editors/GroupByTransformerEditor.tsx
index 91c01232de2..2396e471889 100644
--- a/public/app/features/transformers/editors/GroupByTransformerEditor.tsx
+++ b/public/app/features/transformers/editors/GroupByTransformerEditor.tsx
@@ -24,11 +24,7 @@ interface FieldProps {
   onConfigChange: (config: GroupByFieldOptions) => void;
 }
 
-export const GroupByTransformerEditor = ({
-  input,
-  options,
-  onChange,
-}: TransformerUIProps<GroupByTransformerOptions>) => {
+const GroupByTransformerEditor = ({ input, options, onChange }: TransformerUIProps<GroupByTransformerOptions>) => {
   const fieldNames = useAllFieldNamesFromDataFrames(input, true);
 
   const onConfigChange = useCallback(
@@ -91,7 +87,7 @@ const options = [
   { label: 'Calculate', value: GroupByOperationID.aggregate },
 ];
 
-export const GroupByFieldConfiguration = ({ fieldName, config, onConfigChange }: FieldProps) => {
+const GroupByFieldConfiguration = ({ fieldName, config, onConfigChange }: FieldProps) => {
   const theme = useTheme2();
 
   const styles = getStyles(theme);
@@ -119,7 +115,7 @@ export const GroupByFieldConfiguration = ({ fieldName, config, onConfigChange }:
           />
         </div>
 
-        {config?.operation === GroupByOperationID.aggregate && (
+        {config?.operation && (
           <StatsPicker
             className={styles.aggregations}
             placeholder={t('transformers.group-by-field-configuration.placeholder-select-stats', 'Select stats')}

From 95dd367d791ac86aa9ab75ee2118b8e6758a76c8 Mon Sep 17 00:00:00 2001
From: Ihor Yeromin <yeryomin.igor@gmail.com>
Date: Mon, 14 Jul 2025 16:39:39 +0200
Subject: [PATCH 2/2] feat(transformations): filter selection

---
 .../grafana-data/src/transformations/transformers/groupBy.ts   | 2 +-
 .../features/transformers/editors/GroupByTransformerEditor.tsx | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/packages/grafana-data/src/transformations/transformers/groupBy.ts b/packages/grafana-data/src/transformations/transformers/groupBy.ts
index 8048c17faa7..f6eb212a138 100644
--- a/packages/grafana-data/src/transformations/transformers/groupBy.ts
+++ b/packages/grafana-data/src/transformations/transformers/groupBy.ts
@@ -10,7 +10,7 @@ import { FieldMatcherID } from '../matchers/ids';
 import { DataTransformerID } from './ids';
 import { findMaxFields } from './utils';
 
-const MINIMUM_FIELDS_REQUIRED = 2;
+const MINIMUM_FIELDS_REQUIRED = 1;
 
 export enum GroupByOperationID {
   aggregate = 'aggregate',
diff --git a/public/app/features/transformers/editors/GroupByTransformerEditor.tsx b/public/app/features/transformers/editors/GroupByTransformerEditor.tsx
index 2396e471889..526a9aa705b 100644
--- a/public/app/features/transformers/editors/GroupByTransformerEditor.tsx
+++ b/public/app/features/transformers/editors/GroupByTransformerEditor.tsx
@@ -124,6 +124,9 @@ const GroupByFieldConfiguration = ({ fieldName, config, onConfigChange }: FieldP
             onChange={(stats) => {
               onConfigChange({ ...config, aggregations: stats as ReducerID[] });
             }}
+            filterOptions={(option) =>
+              config?.operation === GroupByOperationID.groupBy ? option.id === ReducerID.count : true
+            }
           />
         )}
       </Stack>