Using jsonb_agg

classic_join.sql

SELECT todo_lists.id AS todo_list_id,
       todo_lists.name,
       todo_items.id AS todo_item_id,
       todo_items.name
FROM todo_ LISTS
LEFT JOIN todo_items ON todo_items.todo_list_id = todo_lists.id;

classic_join_result

+----------------+-------------------------+----------------+-----------------------------------------------+
| todo_list_id   | name                    | todo_item_id   | name                                          |
|----------------+-------------------------+----------------+-----------------------------------------------|
| 0              | methodologies capacitor | 0              | maroon open-source                            |
| 0              | methodologies capacitor | 1              | matrix Suriname                               |
| 0              | methodologies capacitor | 2              | e-tailers Kyat                                |
| 1              | Music workforce         | 3              | violet SSL                                    |
| 1              | Music workforce         | 4              | Beauty European Unit of Account 17(E.U.A.-17) |
| 1              | Music workforce         | 5              | vortals Michigan                              |
| 2              | Concrete Fantastic      | 6              | Frozen indigo                                 |
| 2              | Concrete Fantastic      | 7              | wireless Assistant                            |
| 2              | Concrete Fantastic      | 8              | archive Denar                                 |
+----------------+-------------------------+----------------+-----------------------------------------------+

Join_with_jsonb_agg.sql

SELECT todo_lists.id AS todo_list_id,
       todo_lists.name,
       jsonb_agg(to_jsonb(todo_items) - 'todo_list_id') AS items
FROM todo_lists
LEFT JOIN todo_items ON todo_items.todo_list_id = todo_lists.id
GROUP BY todo_lists.id;

Join_with_jsonb_agg_results

+----------------+-------------------------+----------------------------------------------------------------------------------------------------------------------------------------------+
| todo_list_id   | name                    | items                                                                                                                                        |
|----------------+-------------------------+----------------------------------------------------------------------------------------------------------------------------------------------|
| 0              | methodologies capacitor | [{"id": 0, "name": "maroon open-source"}, {"id": 1, "name": "matrix Suriname"}, {"id": 2, "name": "e-tailers Kyat"}]                         |
| 1              | Music workforce         | [{"id": 3, "name": "violet SSL"}, {"id": 4, "name": "Beauty European Unit of Account 17(E.U.A.-17)"}, {"id": 5, "name": "vortals Michigan"}] |
| 2              | Concrete Fantastic      | [{"id": 6, "name": "Frozen indigo"}, {"id": 7, "name": "wireless Assistant"}, {"id": 8, "name": "archive Denar"}]                            |
+----------------+-------------------------+----------------------------------------------------------------------------------------------------------------------------------------------+