WITH RECURSIVE category_hierarchy AS ( -- Base case: Select root nodes SELECT id, name, parent_id, ARRAY[name] AS path, -- Start hierarchy path as an array ARRAY[x,y,width,height] AS rectData, -- Start hierarchy path as an array 1 AS level FROM categories WHERE parent_id IS NULL UNION ALL -- Recursive case: Append child nodes to hierarchy ..

쿼리WITH RECURSIVE category_hierarchy AS ( -- Base case: Select root nodes SELECT id, name, parent_id, ARRAY[name] AS path, -- Start hierarchy path as an array 1 AS level FROM categories WHERE parent_id IS NULL UNION ALL -- Recursive case: Append child nodes to hierarchy SELECT c.id, c.name, c.parent_id, ch.path ..

Left outer join: a 기준으로 다 나옴SELECT a.id AS table_a_id, a.name AS table_a_name, b.id AS table_b_id, b.description AS table_b_descriptionFROM table_a aLEFT OUTER JOIN table_b b ON a.id = b.a_id;table_a_id | table_a_name | table_b_id | table_b_description-----------+-------------+------------+----------------------1 | Apple | 1 | Fruit2 | Carrot ..

WITH date_diff AS ( SELECT TO_DATE('20250101 132344', 'YYYYMMDD HH24MISS') AS created_date, SYSDATE AS current_date FROM dual)SELECT CASE WHEN current_date - created_date >= 1 THEN TRUNC(current_date - created_date) || ' days' WHEN (current_date - created_date) * 24 >= 1 THEN TRUNC((current_date - created_date) * 24) || ' hours' ..

nanoseconds가 필요하면 SYSTIMESTAMP를 사용해야 함

'2025-01-16T07:14:47Z'를 날짜로 변환하기SELECT TO_DATE('2025-01-16T07:14:47Z', 'YYYY-MM-DD"T"HH24:MI:SS"Z"') FROM DUAL;SELECT TO_CHAR(SYSDATE, 'YYYY-MM-DD"T"HH24:MI:SS"Z"') FROM DUAL;