mysql处置以逗号分开的数据_mysql

mysql处理以逗号分开的数据
假如当前有一条数据
id                emails
1             [email protected],[email protected],[email protected]

现在想要分别取出[email protected],[email protected],[email protected]  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

允许对上面代码进行修剪
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()

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