mysql - Display the number of replies to a message with inner joins in PHP -


anything beyond basic sql statements, not strong point.

i have messaging system i'm coding kind of facebook's instead of separate messages, reply 1 main message, , messages you're participating in displayed in 1 spot.

mail table:

  • mailid
  • mailuser: person sent message
  • mailto
  • mailunread: 1 unread
  • mailsubject
  • mailbody
  • mailcurrency
  • mailtime
  • maildeleted: 1 deleted

relevant fields in mailreply table:

  • mailreplyid
  • mailreplyuser: user that's replying
  • mailreplydeleted: 1 deleted
  • mailreplyto: id of message replied to

original coded didn't count number of replies , worked fine, decided helpful include number.

this had:

select      a.mailid,      a.mailuser,      a.mailto,      b.username usernamea,      c.username usernameb      mail a, users b, users c       (a.mailuser = b.id or a.mailuser = c.id)      , (a.mailto = '".$id."' or a.mailuser = '".$id."')      , a.maildeleted = '0' group a.mailid order a.mailid desc

this attempt:

select     a.mailid,      a.mailuser,      a.mailto,      b.username usernamea,      c.username usernameb      mail a, users b, users c     left join mailreply d      on d.mailreplyto = a.mailid      (a.mailuser = b.id or a.mailuser = c.id)      , (a.mailto = '".$id."' or a.mailuser = '".$id."')      , a.maildeleted = '0' group a.mailid order a.mailid desc

thanks

try this:

select     a.mailid,      a.mailuser,      a.mailto,      b.username fromusername,      c.username tousername,     count(d.mailreplyid) mailcount      mail     inner join users b on b.id=a.mailuserid     inner join users c on c.id=a.mailto     left join mailreply d      on d.mailreplyto = a.mailid     (a.mailto = '".$id."' or a.mailuser = '".$id."')      , a.maildeleted = '0' group a.mailid order a.mailid desc

you need join users table on each side of message usernames. think confusing clause check if current user sender or recipient join specification, that's reason using inner join syntax rather separating tables commas , putting join spec in clause.

you group mail id correctly did, , add in count column on mailreply table. table left joined, right about, return messages count of 0 replies.

hope sorts - there!

james


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