group by - How to avoid group_concat separator duplicate in mysql select result -

i have 2 tables call record , user, fields below

record fields:

• recordid (key)
• userid (key)

user fields:

• userid (key)
• username
• usernote

and want know recordid, username, usernote group recordid here sql

 select record.recordid, group_concat(user.username) usernames , group_concat(user.usernote) usernotes record   left outer join user on record.userid = user.userid    group record.recordid  

now can split usernames , usernotes ',' know every username , usernote

but if there ',' in usernote ,it might make mistakes

for example, ben usernote nice,tall , tom's usernote nice

the sql result be

usernames-> ben,tom

usernotes-> nice,tall,nice

in case usernotes have 3 notes, can't differ 1 tom's note

is there way avoid situation?

or best way can use separator hard appear, '！＠＃＠！'

in real case, have 10 tables related key, if left outer join tables, tons of duplicate rows,

one method different separator:

select r.recordid,        group_concat(u.username separator ';') usernames ,           group_concat(u.usernote separator ';') usernotes record r left outer join      user u      on r.userid = u.userid   group r.recordid ;