mysql while,loop,repeat循环，符合条件跳出循环,游标

DROP PROCEDURE IF EXISTS mywhile;
CREATE PROCEDURE mywhile ()
BEGIN
DECLARE i INT default 0;
outer_label: BEGIN  #设置一个标记并设置开始
while i<10 DO
SET i = i + 1;
IF i > 2 THEN
select '跳出循环' column1;
LEAVE  outer_label;  #满足条件，终止循环，跳转到end outer_label标记
ELSE
SELECT i as column1;
END IF;

end while;
END outer_label;  #设置标记并结束
END
call mywhile;

DROP PROCEDURE IF EXISTS myloop;

CREATE PROCEDURE myloop ()
BEGIN
DECLARE i INT default 0;


loop_label:LOOP#循环开始
SET i = i + 1;
IF i > 3 THEN
select '跳出循环' column1;
LEAVE loop_label;  #终止循环
ELSE
SELECT NOW() as column1;
END IF;
END LOOP;
ENd

call myloop;

DROP PROCEDURE IF EXISTS myrepeat;
CREATE PROCEDURE myrepeat ()
BEGIN
DECLARE i INT default 0;
REPEAT
SET i = i + 1;
until i>2 
end REPEAT;
END

call myrepeat;

DROP PROCEDURE IF EXISTS myCURSOR;
CREATE PROCEDURE myCURSOR ()
BEGIN
DECLARE user_name VARCHAR(32);


/* 声明游标 */
DECLARE my_cursor CURSOR FOR select nickname from users;


/* 打开游标 */
OPEN my_cursor;
sale_loop: LOOP
FETCH my_cursor INTO user_name;
select user_name;
END LOOP;
-- 关闭游标
close my_cursor;
end

call myCURSOR;