http://blog.itpub.net/559237/viewspace-438942/
今天花了半天时间来研究mysql的存储过程函数和触发器的创建，觉得和oracle的大同小异，只是语法上更艰涩点，可能是先入为主吧，经过多次失败，终于创建成功，需要注意创建前要先执行“delimiter //”，创建后以“//”结束，还有就是怎么没有像plsql dev这样的工具来调试程序呢。和oracle的在语法上主要不同点有如下几方面：
1.declare放到了begin体里面
2.给变量复制是set xxx = 1
3. 在事务开始时要start transaction;
4.函数的返回是returns（oracle的是return），返回类型也需要给varchar等类型定义长度
还有就是在网上翻了个遍，手册也看了，就是没有找到存储过程的自定义异常，不知道到底有没有。
以下举几个例子：
没有create or replace语句，只要先删除再创建
delimiter$$
create function f_a(ai_n int) returns varchar(64) begin declare vs_res varchar(64); declare vi_count int; select max(n),count(1) into vs_res ,vi_count from d where i = ai_n; if vs_res is null then set vs_res = ''; end if; return vs_res; end$$ DELIMITER ;
如果出现如下错误，需要设置set global log_bin_trust_function_creators=TRUE。 ERROR 1418 (HY000): This function has none of DETERMINISTIC, NO SQL, or READS SQL DATA in its declaration and binary logging is enabled (you *might* want to use the less safe log_bin_trust_function_creators variable)
mysql> select f_a(1); +--------+ | f_a(1) | +--------+ | 直播 | +--------+ 1 row in set (0.05 sec)
存储过程： delimiter$$
create procedure p_a(in ai_num int) begin declare vi_loop int default 0; declare vi_maxid,vi_count int; select max(id),count(1) into vi_maxid,vi_count from a; if vi_count = 0 then set vi_maxid = 0; end if; start transaction; set vi_loop = 1; while vi_loop < ai_num do set vi_maxid = vi_maxid + 1; insert into u values(vi_maxid,vi_maxid); set vi_loop = vi_loop + 1; end while; commit; end$$
delimiter$$
delimiter $$
create procedure curdemo() begin declare done int default 0; declare a char(16); declare b,c,d int; declare cur1 cursor for select id,data from test.t1; declare cur2 cursor for select i from test.t2; declare continue handler for sqlstate '02000' set done = 1; open cur1; open cur2; repeat fetch cur1 into a, b; fetch cur2 into c; if not done then set d = sign(b - c); case d when 0 then insert into test.t3 values (a,0); when 1 then insert into test.t3 values (a,b); when -1 then insert into test.t3 values (a,c); end case; end if; until done end repeat; close cur1; close cur2; end$$ delimiter; 触发器： 和oracle差不多，就是需要开头delimiter //，结尾用//，new前的：去掉即可。 mysql> drop trigger trg_a mysql> delimiter // mysql> create trigger trg_a before insert on a -> for each row
-> insert into b set id=new.id,i=111; -> delete from c where a=new.id; -> end; -> // Query OK, 0 rows affected (0.02 sec)
运行过程 msql>call p_a(1000); 通过show create procedure/function name可以查看过程和函数的结果 如mysql>show create procedure p_a;
####以下是项目中的例子
drop FUNCTION `manage`.`f_getarea`; DELIMITER $$
CREATE FUNCTION `manage`.`f_getarea`(as_areaid varchar(32), ai_i int) #ai_i层数 #select f_getarea('1.22.333.55',2) can get '1.22.' RETURNS varchar(32) BEGIN declare vi_temp,vi_i,vi_instr tinyint(2); #不可能超过5层 if ai_i > 5 or ai_i < 1 then return ''; end if; set vi_temp = 0,vi_i = 0; while 1 = 1 do set vi_instr = vi_temp; set vi_temp = locate('.',as_areaid,vi_temp+1); if vi_temp = 0 then return substr(as_areaid,1,vi_instr); end if; if vi_i = ai_i then return substr(as_areaid,1,vi_instr); end if; set vi_i = vi_i + 1; end while; return ''; END$$
DELIMITER ;