chore: import upstream snapshot with attribution

examples/custom form component/form_action.sql

@@ -0,0 +1,28 @@
+-- remove all existing members from this group
+delete from group_members where group_id = 1;
+
+-- add the selected members to this group
+-- This query takes a JSON array and converts it to rows
+-- :selected_items contains a JSON array of user IDs, e.g. ["1", "2", "3"], generated by SQLPage from the multiple-select box answers posted by the browser
+-- json_table breaks down the JSON array into individual rows
+-- '$[*]' means "look at each element in the root array"
+-- columns (id int path '$') extracts each array element as an integer into a column named 'id'
+-- The result is a temporary table with one integer column (id) and one row per array element
+insert into group_members (group_id, user_id)
+select 1, id
+from json_table(
+    :selected_items,
+    '$[*]' columns (id int path '$')
+) as submitted_items;
+
+select 'alert' as component, 'Group members successfully updated !' as title, 'success' as color;
+
+select 'list' as component, 'Users in this group' as title;
+
+select name as title, email as description
+from users
+join group_members on users.id = group_members.user_id
+where group_members.group_id = 1;
+
+select 'button' as component;
+select 'Go back' as title, 'index.sql' as link;