API/Queries/Attributes.md

@@ -394,6 +394,51 @@ A column defined by select and as:
 
 # Group By
 
+To group a result by one or more [columns](#permitted-column-names), `group_by` may be used.
+
+## Restrictions
+
+The value may be either one string or an array of strings of [permitted column names](#permitted-column-names).
+
+## Examples
+
+This will return a list of modules names and how many entites each modules has:
+
+`POST /data/system/module/query`
+
+```
+{
+  "attrs": {
+    "join": "system__entity__module",
+    "columns": "me.name",
+    "+select": [
+      {
+        "count": "system__entity__module.id"
+      }
+    ],
+    "+as": [
+      "entity_count"
+    ],
+    "group_by": "me.name"
+  }
+}
+```
+
+`POST /data/extensions/client_meta_data/query`
+
+```json
+{
+  "attrs": {
+    "select": [
+      {
+        "count": "me.id"
+      },
+      "settings->>'enabled'"
+    ],
+    "group_by": "settings->>'enabled'"
+  }
+}
+```
 
 # Collapse