mysql存储过程的注意点
以下为我写的一个例子：主要功能是把OA的弹窗提醒功能与redmine连接在一起；
delimiter //
create trigger t_trigger AFTER insert on issues for each ROW
BEGIN
DECLARE retValue INTEGER;
DECLARE tmpname varchar(255);
DECLARE title varchar(255) character set utf8;
DECLARE tmpproject_id INTEGER;
declare done tinyint(1) default 0;
DECLARE cur1 CURSOR for
select login from users where id in (select user_id from members where members.project_id = new.project_id);
DECLARE CONTINUE HANDLER FOR NOT FOUND set done = 1;
set tmpproject_id = new.project_id;
set title = new.subject;
open cur1;
FETCH cur1 into tmpname;
lable1: WHILE( tmpname is not NULL) DO
IF done = 1 THEN
LEAVE lable1;
END IF;
select count(*) into retvalue from issues where my_test(tmpname, title);
FETCH cur1 into tmpname;
END WHILE;
END;
写mysql存储过程应注意的几点：
1、声明变量（declare）时要注意字符集，用变量存储表字段时，表字段与变量的字符编码要一致。
2、mysql的字符合并不能用‘+’号，必须用concat函数。
3、每个游标必须使用不同的declare continue handler for not found set done=1来控制游标的结束。
BEGIN
declare rt VARCHAR(100) CHARACTER SET gbk DEFAULT NULL;
declare done tinyint(1) default 0;
DECLARE ttname VARCHAR(60) CHARACTER SET gbk DEFAULT NULL;
DECLARE tsqltxt VARCHAR(512) CHARACTER SET gbk DEFAULT NULL;
DECLARE tremarks VARCHAR(60) CHARACTER SET gbk DEFAULT NULL;
DECLARE tfield VARCHAR(60) CHARACTER SET gbk DEFAULT NULL;
DECLARE curtable CURSOR FOR
SELECT distinct TABLE_name
FROM information_schema.TABLEs where TRIM(TABLE_COMMENT)<>'' and TRIM(TABLE_COMMENT)<>'VIEW' order by TABLE_name;
declare continue handler for not found set done=1;
set NAMES 'utf8';
drop table if EXISTS GetTableSQL;
CREATE TABLE `gettablesql` (
`tbname` varchar(60) CHARACTER SET gbk DEFAULT NULL,
`sqltxt` varchar(4096) CHARACTER SET gbk DEFAULT NULL,
`tabletitle` varchar(51) CHARACTER SET gbk DEFAULT NULL
) ENGINE=InnoDB;
open curtable;
tableloop:
LOOP
set tsqltxt='select';
FETCH curtable
INTO ttname;
IF done = 1 THEN
LEAVE tableloop;
END IF;
-- select ttname;
BEGIN
declare done1 tinyint(1) default 0;
DECLARE curfield CURSOR FOR
SELECT COLUMN_NAME,COLUMN_COMMENT
FROM information_schema.COLUMNS where upper(TABLE_name)=upper(ttname) and (COLUMN_COMMENT<>'') ;
declare continue handler for not found set done1=1;
OPEN curfield;
fieldloop:
LOOP
FETCH curfield
INTO tfield,tremarks;
IF done1 = 1 THEN
LEAVE fieldloop;
END IF;
if tsqltxt='select' THEN
set tsqltxt=CONCAT(tsqltxt,' ',tfield,' ','''',tremarks,'''');
ELSE
set tsqltxt=CONCAT(tsqltxt,',',tfield,' ','''',tremarks,'''');
END IF;
END LOOP fieldloop;
close curfield;
set tsqltxt=concat(tsqltxt,' from ',ttname);
insert into GetTableSQL values(ttname,tsqltxt,'');
END;
END LOOP tableloop;
close curtable;
update GetTableSQL as G set tabletitle=(select TABLE_COMMENT from information_schema.TABLEs s
where (trim(s.TABLE_COMMENT)<>'') and g.tbname=s.table_name );
select cast(count(*) as char) into rt from GetTableSQL;
set rt=concat('成功更新',rt,'个表的表名注释和字段注释到字典库GetTableSQL中！');
SELECT rt;
END