mysql (:kabel_name:loop...end loop"; "repeat....end repeat";"while ... do .... end while"

drop PROCEDURE if exists test1;
create procedure test1()
begin
    declare i int;
    set i=1;
while i<=30 do
        update blog.car1_myarticle 
        set blog.car1_myarticle.brief_content=i
        where car1_myarticle.id=i;
        set i=i+1;
end while;
end;
----------------------------------------
drop PROCEDURE if exists test1;
create procedure test1()
begin
    declare i int;
    set i=1;
exit_a:loop  -- 定义一个标签为 "exit_a"
        update blog.car1_myarticle 
        set blog.car1_myarticle.brief_content=i
        where car1_myarticle.id=i;
        set i=i+1;
    if i>30 THEN
        LEAVE exit_a;  -- 离开指定的标签 "exit_a"
    end if;
end loop;
end;
----------------------------------------
drop procedure if EXISTS test1;
create procedure test3()
begin
    declare i,n int;
    set i=1;
    set n=30;
REPEAT
            update blog.car1_myarticle 
            set blog.car1_myarticle.brief_content=i
            where car1_myarticle.id=i;
set i=i+1;
until i>n
end REPEAT;
end;