mysql处理以逗号分开的数据

假如当前有一条数据
id                emails
1             [e-mail],[e-mail],[e-mail]

现在想要分别取出[e-mail],[e-mail],[e-mail]  存入另外一个表中 表只有俩个字段id,email
如果用java程序，那么很简单，直接根据ID查询出这条记录，然后对这个字符做split以逗号分割就可以了，但是sql中没有split函数，如果实现，
以下是用sql写的处理数据的存储过程
drop PROCEDURE if EXISTS dealEmail 
CREATE PROCEDURE dealEmail(in totalCount INT) -- totalCount是count(*)个数，需要处理多少行数据
BEGIN
DECLARE limitcount INT(10);  -- 保证每次查询仅有一条数据 
DECLARE comma INT(10);  -- emails数据中，的个数
DECLARE ema VARCHAR(500); -- 插入另外一张表的email数据 
DECLARE repeatcount INT(10); -- 判断是否有重复数据
DECLARE emailsStr VARCHAR(500);  -- 本次截取后的字符 如1,2,3 本次操作留下的字符是2，那么emailsStr=2
DECLARE totalemailsStr VARCHAR(1000);  -- 所有截取替换操作前的所有字符  如1,2,3  1,2已经操作 totalemailStr=1,2
DECLARE subcount INT(10); -- 判断当前是第几次截取
DECLARE appendEmails VARCHAR(1000);  -- 为email数据最后追加,
set limitcount=0;
-- LOCATE查询字符串第一次出现的位置  left函数  左截取
while(totalCount>0) DO
   SELECT LENGTH(emails)-LENGTH(REPLACE(emails,',','')) into comma from t_author where emails!='' limit limitcount,1;
   set subcount=1;
   set totalemailsStr='';
   set appendEmails ='';
          if(comma<=0) THEN
select emails into ema from t_author where emails!='' limit limitcount,1;
select count(pid) into repeatcount from t_email where email=ema;
if(repeatcount = 0) THEN -- 判断当前即将插入数据是否存在
INSERT into t_email(email) values(ema);
END IF;

ELSE
    WHILE(comma>=0) DO
IF(subcount=1) THEN
     /**第一次截取  */
     select SUBSTR(emails,1,LENGTH(left(emails, LOCATE(',',emails)-1))) into ema from t_author where emails!='' limit limitcount,1;
     SELECT left(emails, LOCATE(',',emails)) into totalemailsStr FROM t_author where emails!='' limit limitcount,1;
     select count(pid) into repeatcount from t_email where email=ema;
     if(repeatcount = 0) THEN
INSERT into t_email(email) values(ema);
     END IF;

     set subcount = subcount + 1;
     set comma = comma - 1;
     ELSE
select concat(emails,',') into appendEmails from t_author where emails!='' LIMIT limitcount,1;
select SUBSTR(REPLACE(appendEmails,totalemailsStr,''),1,LENGTH(left(REPLACE(appendEmails,totalemailsStr,''), LOCATE(',',REPLACE(appendEmails,totalemailsStr,''))-1))) into ema from t_author where emails!='' limit limitcount,1;
SELECT left(REPLACE(appendEmails,totalemailsStr,''), LOCATE(',',REPLACE(appendEmails,totalemailsStr,''))) into emailsStr  from t_author where emails!='' limit limitcount,1;
set totalemailsStr = concat(totalemailsStr,emailsStr);
select count(pid) into repeatcount from t_email where email=ema;
if(repeatcount = 0) THEN
INSERT into t_email(email) values(ema);
END IF;

set subcount = subcount + 1;
set comma = comma - 1;
END IF;
END WHILE;
end IF;
set totalCount = totalCount-1;
set limitcount = limitcount+1;
end WHILE;
END;


CALL dealEmail(568);


使用的是mysql5.5




[b]允许对上面代码进行修剪[/b]
drop PROCEDURE if EXISTS dealEmail

CREATE PROCEDURE dealEmail()
BEGIN
DECLARE limitcount INT(10);  -- 保证每次查询仅有一条数据 
DECLARE comma INT(10);  -- emails数据中，的个数
DECLARE ema VARCHAR(500); -- 插入另外一张表的email数据 
DECLARE searchname VARCHAR(500); -- 插入另外一张表的email数据 
DECLARE repeatcount INT(10); -- 判断是否有重复数据
DECLARE emailsStr VARCHAR(500);  -- 本次截取后的字符 如1,2,3 本次操作留下的字符是2，那么emailsStr=2
DECLARE totalemailsStr VARCHAR(1000);  -- 所有截取替换操作前的所有字符  如1,2,3  1,2已经操作 totalemailStr=1,2
DECLARE subcount INT(10); -- 判断当前是第几次截取
DECLARE appendEmails VARCHAR(1000);  -- 为email数据最后追加,
DECLARE totalCount INT(10);
set limitcount=0;
SELECT count(1) into totalCount from t_author where emails is not null;
-- LOCATE查询字符串第一次出现的位置  left函数  左截取
while(totalCount>0) DO
SELECT LENGTH(emails)-LENGTH(REPLACE(emails,',','')) into comma from t_author where emails is not null limit limitcount,1;
set subcount=1;
set totalemailsStr='';
set appendEmails ='';
if(comma<=0) THEN
SELECT emails,researchname into ema,searchname from t_author where emails is not null limit limitcount,1;
/**SELECT count(pid) into repeatcount from t_email where email=ema; */
INSERT into t_email(email,researchname) values(trim(ema),trim(searchname));
ELSE
SELECT concat(emails,',') into appendEmails from t_author where emails is not null LIMIT limitcount,1;
WHILE(comma>=0) DO
SELECT SUBSTR(REPLACE(appendEmails,totalemailsStr,''),1,LENGTH(left(REPLACE(appendEmails,totalemailsStr,''), LOCATE(',',REPLACE(appendEmails,totalemailsStr,''))-1))),researchname into ema,searchname from t_author where emails is not null limit limitcount,1;
SELECT left(REPLACE(appendEmails,totalemailsStr,''), LOCATE(',',REPLACE(appendEmails,totalemailsStr,''))) into emailsStr  from t_author where emails is not null limit limitcount,1;
set totalemailsStr = concat(totalemailsStr,emailsStr);
/**SELECT count(pid) into repeatcount from t_email where email=ema; */
INSERT into t_email(email,researchname) values(trim(ema),trim(searchname));
set subcount = subcount + 1;
set comma = comma - 1;
END WHILE;
end IF;
set totalCount = totalCount-1;
set limitcount = limitcount+1;
end WHILE;
END;
CALL dealEmail()
[b]如果数据量大，mysql会执行很长时间，现在提供一种快速的办法，再次更新，嘻嘻
使用的时游标，网上很多说使用游标处理数据不要超过1W，否则会很慢，但是我现在还不知道更好的办法，只能先用这个，后续有好的，再次更新，然后修改mysql不自动提交，这样效率会更好。不多说了，贴代码[/b]
set autocommit=0;
drop PROCEDURE if EXISTS dealEmail;
CREATE PROCEDURE dealEmail()
BEGIN
DECLARE comma INT(10);  -- emails数据中，的个数
DECLARE ema VARCHAR(500); -- 插入另外一张表的email数据 
DECLARE searchname VARCHAR(500); -- 插入另外一张表的email数据 
DECLARE emailsStr VARCHAR(500);  -- 本次截取后的字符 如1,2,3 本次操作留下的字符是2，那么emailsStr=2
DECLARE totalemailsStr VARCHAR(1600);  -- 所有截取替换操作前的所有字符  如1,2,3  1,2已经操作 totalemailStr=1,2
DECLARE subcount INT(10); -- 判断当前是第几次截取
DECLARE appendEmails VARCHAR(1600);  -- 为email数据最后追加,
DECLARE id INT(10);
DECLARE beforeid INT(10);
DECLARE cur CURSOR for select pid  from t_author;
DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET id=0;
open cur;
FETCH cur into id;
WHILE id !=0 DO
SELECT LENGTH(emails)-LENGTH(REPLACE(emails,',','')) into comma from t_author where pid=id;
set subcount=1;
set totalemailsStr='';
set appendEmails ='';
if(comma<=0) THEN
SELECT emails,researchname into ema,searchname from t_author where  pid=id;
INSERT into t_email(email,researchname) values(trim(ema),trim(searchname));
ELSE
SELECT concat(emails,',') into appendEmails from t_author where  pid=id;
WHILE(comma>=0) DO
SELECT SUBSTR(REPLACE(appendEmails,totalemailsStr,''),1,LENGTH(left(REPLACE(appendEmails,totalemailsStr,''), LOCATE(',',REPLACE(appendEmails,totalemailsStr,''))-1))),researchname into ema,searchname from t_author where pid=id;
SELECT left(REPLACE(appendEmails,totalemailsStr,''), LOCATE(',',REPLACE(appendEmails,totalemailsStr,''))) into emailsStr  from t_author where pid=id;
set totalemailsStr = concat(totalemailsStr,emailsStr);
INSERT into t_email(email,researchname) values(trim(ema),trim(searchname));
set subcount = subcount + 1;
set comma = comma - 1;
END WHILE;
end IF;
set beforeid = id;
FETCH cur into id;
END WHILE;

CLOSE cur;
commit;
END

DELETE from t_email;
commit;
call dealEmail();
SELECT count(*) from t_email;