[TYPO3-dev] Newbie: IRRE question

[Olivier Laurent]

I'm currently developing my first plugin with Typo3.
I bought Dmitry Dulepov's book "TYPO3 Extension development".

My plugin uses two different tables. Normally I would have used what you 
call Many-to-many relation (ie a third table storing various 
relationships between two other tables). But Dmitry seemed to be a great 
supporter of IRRE (inline relationship?) So I picked it up :-).

But now I'm in trouble, I can't find the correct SQL query, it doesn't 
seem I can make a join

Here is my problem
I've a got a table for documents, documents can be part of several groups:
so it is
uid int
documentpath string (varchar i guess)
groups (comma separated lists of uid)


and a second table for groups
uid
groupname string (varchar i guess)

let's say that I want all documents from the group name "administrative" 
which has the uid 2 for example,
how do you build your SQL query to select all documents being part of 
this group?

In a traditionnal approach I would have a third table storing the 
different relatshionships between these two tables and all I would have 
to do is to make a select wich a join statement. How do you solve this 
problem with IRRE?

Olivier