6ht9qFmD

1drop table if exists `test_fib`;
2
3create table `test_fib` (
4  `idx` bigint unsigned not null auto_increment, 
5  `num` bigint unsigned not null, 
6  primary key (`idx`));
7  
8insert into `test_fib` (`num`) values (1);
9insert into `test_fib` (`num`) values (1);
10select * from `test_fib`;
11
12drop procedure if exists `sp_test_fib`;
13
14delimiter $$
15create procedure `sp_test_fib` (in `in_idx` bigint unsigned)
16begin
17  declare `max_idx` bigint unsigned default 0;
18  declare `out_num` bigint unsigned default 0;
19  declare `diff_idx` bigint unsigned default 0;
20  declare `next_max_num` bigint unsigned default 0;
21  
22  select max(`idx`) into `max_idx` from `test_fib`;
23  
24  if `max_idx` >= `in_idx` then
25    select `num` into `out_num` from `test_fib` where `idx` = `in_idx`;
26  else
27    set `diff_idx` = `in_idx` - `max_idx`;
28    while `diff_idx` > 0 do
29      set `next_max_num` = 
30        (select `num` from `test_fib` where `idx` = (`max_idx` - 1)) + 
31        (select `num` from `test_fib` where `idx` = `max_idx`);
32      insert into `test_fib` (`num`) values (`next_max_num`);
33      set `max_idx` = `max_idx` + 1;
34      set `diff_idx` = `diff_idx` - 1;
35	end while; 
36    select max(`num`) into `out_num` from `test_fib`;
37  end if;
38  
39  select `out_num`;
40end$$
41DELIMITER ;
42
43call `sp_test_fib`(50);
44call `sp_test_fib`(3);
45select * from `test_fib`;