[prev in list] [next in list] [prev in thread] [next in thread] 

List:       php-general
Subject:    Re: [PHP] Recursion with database tables
From:       Ernest E Vogelsinger <ernest () vogelsinger ! at>
Date:       2003-02-19 12:49:41
[Download RAW message or body]

At 14:43 19.02.2003, Jono Bacon said:
--------------------[snip]--------------------
>At the moment I have three tables: Topic, Message, Comment. A topic has 
>messages and each message can have comments. I have set this up with a 
>table each and a field for the id of the parent (e.g. a comment will 
>have the id of the message that it refers to).
>
>My mate said to me that I should really put all of this in one big table 
>with a parent and child field. He said that my code should then figure 
>out what is the child of what and how it is displayed.

This are one-to-many relationships? If yes, then your mate is wrong, you
can't easily implement one-to-many using a single table.

A problem like yours is usually laid out like this (pseudocode):

TABLE TOPIC
  id       integer primary key;
  topic    varchar;

TABLE MESSAGE
  id       integer primary key;
  id_topic integer foreign key references TOPIC(id);
  message  text;

TABLE COMMENT
  id       integer primary key;
  id_message integer foreign key references MESSAGE(id);
  comment  text;

>I have two questions about this:
>
>    1. First, is this idea of using one big table with parent/child 
>fields better than my seperate table approach?

See above.

>    2. Secondly, how would I write the logic for the single table approach.

Forget it, use the approach above :)


-- 
   >O     Ernest E. Vogelsinger
   (\)    ICQ #13394035
    ^     http://www.vogelsinger.at/



-- 
PHP General Mailing List (http://www.php.net/)
To unsubscribe, visit: http://www.php.net/unsub.php

[prev in list] [next in list] [prev in thread] [next in thread]