Re: Database Tables Relation Issue

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Yes that's right, until now I didn't spent time on writing another table
because my job was to develop some internal system to manage the company
projects & HR (we are too small, it won't make the difference).

Well umm thanks, I'm going to write the blueprints for the tables :P

On Fri, Jan 30, 2009 at 4:10 PM, Bastien Koert <phpster@xxxxxxxxx> wrote:

>
>
> On Fri, Jan 30, 2009 at 8:37 AM, Andrew Ballard <aballard@xxxxxxxxx>wrote:
>
>> On Fri, Jan 30, 2009 at 3:38 AM, Nitsan Bin-Nun <nitsan@xxxxxxxxxxxx>
>> wrote:
>> > Hi there,
>> >
>> > I'm working on something similar to mailing list in which every
>> registered
>> > user has the ability to create a mailing list and join others mailing
>> lists.
>> >
>> > My users table is something like that (in short):
>> >
>> > CREATE TABLE IF NOT EXISTS `users` (
>> >    `id` INT( 11 ) UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
>> >    `email` VARCHAR( 255 ) NOT NULL,
>> >    `password` CHAR( 64 ) NOT NULL,
>> >    UNIQUE (`email`)
>> > );
>> >
>> > And my mailinglists table is as following:
>> > CREATE TABLE IF NOT EXISTS `lists` (
>> >    `id` INT( 11 ) UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
>> >    `creator_id` INT( 11 ) UNSIGNED NOT NULL,
>> >    `name` VARCHAR( 255 ) NOT NULL,
>> >    `description` TEXT NOT NULL
>> > );
>> >
>> > I must have relation between the users table and the lists table, but
>> I'm
>> > not sure what is the best way to implement it.
>> >
>> > I have thought of using comma-separated ID's in special field in the
>> lists
>> > table of the users who have joined that specific list, but I have also
>> > thought of doing the same at the users table, then I had another
>> solution
>> > which is to create new table:
>> >
>> > create table `relations` (
>> >  `listid` int(11),
>> >  `userid` int (11)
>> > );
>> >
>> > Which will contain the relations.
>> >
>> > I want it to be optimised so when I'm fetching the mailinglists that a
>> > specific user is registered (by user id) to and when I'm fetching the
>> users
>> > in specific mailinglist (by mailinglist id) it will be the fastest.
>> >
>> > The question itself is kinda newbie but I have to make sure it is as
>> > scalable as much because in few weeks it will have 10-20 unique
>> visitors/DAY
>> > ;)
>> >
>> > --
>> > ?>
>> > Nitsan Bin-Nun
>> > Web Applications Developer
>> > nitsan@xxxxxxxxxxxx
>> > 972-52-5722039
>> >
>>
>> I will second the other replies and say use the relation table. I
>> would only add that your relation table definition should include a
>> two-column primary key on both listid and userid, as this will ensure
>> that each user can be subscribed to a list no more than one time.
>>
>> CREATE TABLE `relations` (
>>    `listid` int(11) UNSIGNED NOT NULL,
>>    `userid` int(11) UNSIGNED NOT NULL,
>>    PRIMARY KEY `PK_relations` ( `listid`, `userid`)
>> );
>>
>>
>> Another nice thing about this relations table is that you can later
>> expand it to include other things, such as defining the relationship
>> of a user to a list (moderator, administrator, subscriber, etc.) if
>> that becomes necessary.
>>
>> Andrew
>>
>> --
>> PHP General Mailing List (http://www.php.net/)
>> To unsubscribe, visit: http://www.php.net/unsub.php
>>
>> Third table is the way to go. From a performance perspective, with a
> packed field (values delimited in some way) you would likely be doing a LEFT
> LIKE or FULL LIKE (%value or %value%) statement which causes full tables
> scans since the index can't be used. That is much slower than querying a
> simple table with single values where the index can be used.
>
> --
>
> Bastien
>
> Cat, the other other white meat
>



-- 
?>
Nitsan Bin-Nun
Web Applications Developer
nitsan@xxxxxxxxxxxx
972-52-5722039

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