plsql - 循环plsql的反向游标

Question

有没有办法使用plsql按降序迭代游标？

我试过这个：

FOR item IN REVERSE items 
LOOP  
-- do stuff
END LOOP;

但它似乎忽略了反向关键字。

有什么建议么？

Answer 1

确定数据遍历顺序的是 SQL 子句，因此只需在查询中应用适当的 ORDER BY。

Answer 2

DECLARE
cursor c1 is Select * FROM table_1
where (something)
order by (id..whatever you want) DESC; --decrement
v_variable.table%rowtype;
BEGIN
open c1;

fetch c1 into variable; -- will fetch  first row...but it will be DESC

close c1;

END;

类似的东西......或者

FOR i1 IN c1
LOOP
i1.id...
something...
END LOOP;

或者

FOR i2 IN (Select * FROM table_1
    where (something)
    order by (id..whatever you want) DESC) 
LOOP
--something
END LOOP;

Answer 3

由于您没有任何要排序的列，请尝试使用 order by rownum