MySql(14)--MySQL 循环语句

– 求N以内数的和
– while循环语句

delimiter //
create function testfunc(n int)
returns int
begin
declare num int default 0;
declare sum int default 0;
while num < n do
set num = num +1;
set sum = sum + num;
end while;
return sum;
end//
delimiter ;

select testfunc(20);
返回结果210

– loop循环语句

delimiter //
drop function if exists testfunc//
create function testfunc(n int)
returns int
begin
declare num int default 0;
declare sum int default 0;
lab1:loop
set num = num + 1;
set sum = sum + num;
if num>=n then
leave lab1;
end if;
end loop lab1;
return sum;
end//
delimiter ;

select testfunc(20);
返回值210

– repeat循环语句

delimiter //
drop function if exists testfunc//
create function testfunc(n int)
returns int
begin
declare num int default 0;
declare sum int default 0;
repeat
set num = num +1;
set sum = sum + num;
until num>=n
end repeat;
return sum;
end//
delimiter ;

select testfunc(20);
返回值210