我们有一个用pl/sql(oracle)编写的函数如下所示:
CREATE OR REPLACE PROCEDURE folder_cycle_check (folder_key IN NUMBER, new_parent_folder_key IN NUMBER) IS
parent_of_parent NUMBER;
ILLEGAL_CYCLE EXCEPTION;
CURSOR parent_c IS
SELECT parent_folder_key FROM folder
WHERE folder_key = new_parent_folder_key;
BEGIN
IF folder_key = new_parent_folder_key THEN
RAISE ILLEGAL_CYCLE;
END IF;
FOR parent_rec IN parent_c LOOP
BEGIN folder_cycle_check(folder_key, parent_rec.parent_folder_key); END;
END LOOP;
END;
现在,我需要使用pl/pgsql(PostgreSQL)重新编写相同的过程,以实现类似的功能。请帮助我并发送该pl/pgsql函数。
编辑(来自评论的格式化代码)
CREATE OR REPLACE FUNCTION folder_cycle_check(IN folder_key INTEGER, IN new_parent_folder_key INTEGER)
RETURNS VOID
AS $procedure$
DECLARE parent_of_parent INTEGER;
PARENT_C CURSOR FOR
SELECT parent_folder_key
FROM folder
WHERE folder_key = new_parent_folder_key;
BEGIN
IF folder_key = new_parent_folder_key THEN
RAISE EXCEPTION 'ILLEGAL_CYCLE';
END IF
FOR parent_rec IN (SELECT parent_folder_key FROM folder WHERE folder_key = new_parent_folder_key) LOOP
PERFORM folder_cycle_check(folder_key,parent_rec.parent_folder_key);
END LOOP;
RETURN;
END;
$procedure$
LANGUAGE plpgsql;