Oraclepl_sql中实现continue的方法

文章作者 100test 发表时间 2007:12:01 14:50:31
来源 100Test.Com百考试题网

CREATE TABLE AREAS
(
RADIUS NUMBER(5),
AREA NUMBER(14,2)
).

方法一：使用 goto

DECLARE
pi CONSTANT NUMBER (9, 7) := 3.1415927.
radius INTEGER (5).
area NUMBER (14, 2).
BEGIN
radius := 0.

LOOP

<<here>>
radius := radius 1.

IF radius = 4
THEN
GOTO here.
ELSE
area := pi * POWER (radius, 2).

INSERT INTO areas
VALUES (radius, area).

EXIT WHEN area > 100.
END IF.
END LOOP.

COMMIT.
EXCEPTION
WHEN OTHERS
THEN
ROLLBACK.
RAISE.
END.

-- 方法二：使用 exception

-- 利用系统 exception
DECLARE
pi CONSTANT NUMBER (9, 7) := 3.1415927.
radius INTEGER (5).
area NUMBER (14, 2).
some_variable NUMBER (14, 2).
BEGIN
radius := 0.

LOOP
BEGIN
radius := radius 1.
some_variable := 1 / (radius - 4).
area := pi * POWER (radius, 2).

INSERT INTO areas
VALUES (radius, area).

EXIT WHEN area > 100.
EXCEPTION
WHEN ZERO_DIVIDE
THEN
NULL.
END.
END LOOP.

COMMIT.
EXCEPTION
WHEN OTHERS
THEN
ROLLBACK.
RAISE.
END.