MySQL中的For循环示例

Question

在MySQL中，我有一个带有For循环的存储过程：DELIMITER $$  CREATE PROCEDURE ABC()   BEGIN      DECLARE a INT Default 0 ;      simple_loop: LOOP         SET a=a+1;         select a;         IF a=5 THEN            LEAVE simple_loop;         END IF;   END LOOP simple_loop;END $$它总是打印1。MySQL for循环的正确语法是什么？

Answer 1

drop table if exists foo;

create table foo

(

id int unsigned not null auto_increment primary key,

val smallint unsigned not null default 0

)

engine=innodb;

drop procedure if exists load_foo_test_data;

delimiter #

create procedure load_foo_test_data()

begin

declare v_max int unsigned default 1000;

declare v_counter int unsigned default 0;

  truncate table foo;

  start transaction;

  while v_counter < v_max do

    insert into foo (val) values ( floor(0 + (rand() * 65535)) );

    set v_counter=v_counter+1;

  end while;

  commit;

end #

delimiter ;

call load_foo_test_data();

select * from foo order by id;