MySQL-procedure小試牛刀
根據spam_keyword表中的kid對word列逐行逐字分割到t表中，並且統計每個字的數量。
用了兩層循環，外循環游標讀行，內循環stroo++讀字。
drop procedure if exists proc134f;
CREATE PROCEDURE proc134f()
BEGIN
declare kidoo int;
declare tid int;
declare stroo int;
declare str varchar(255);
declare strlength int;
declare istr varchar(3);
declare istr_cnt int;
declare done int;-- 游標用
declare cur_kid CURSOR for select kid from spam_keyword;-- 游標用
declare continue handler for not found set done=1;-- 游標用，據說是直達引擎的通道
set tid=0;
delete from t;
open cur_kid;-- 開啟游標
loop1:loop-- 開啟1層外循環
fetch cur_kid into kidoo; -- 從定義的范圍中讀取下一行並賦予
if done=1 then leave loop1;end if;-- 判斷是否 found 下一行，否則跳出
select word into str from spam_keyword where kid=kidoo;
set str=replace(str,' ','');
set strlength=char_length(str);
set stroo=0;
loop2:loop-- 2層內循環
set stroo=stroo+1;
set istr=substr(str,stroo,1);
select count(*) into istr_cnt from t where t=istr;-- 計數
if istr_cnt<>0 then update t set cnt=cnt+1 where t=istr;else
set tid=tid+1;
insert into t set id=tid,t=istr,cnt=1;end if;
if stroo>=strlength then leave loop2;end if;end loop loop2;
set done=0;
end loop loop1;
close cur_kid;-- 關閉游標
select * from t order by cnt desc;
END;
