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If you are starting with this (which could be the result from a table subquery) ... +----+----------------------+------------+-----------------+----------+ | id | disciplina | moduloUfcd | idcpDisciplinas | anoTurma | +----+----------------------+------------+-----------------+----------+ | 58 | Comunicação Visual | 8599 | 49 | 11 | | 59 | Comunicação Visual | 133 | 49 | 11 | | 60 | Comunicação Visual | 134 | 49 | 10 | +----+----------------------+------------+-----------------+----------+ then this query ... SELECT group_concat(id separator ', ') as ids , disciplina , group_concat(moduloUfcd separator ', ') as mods , idcpDisciplinas , anoTurma FROM gmc GROUP BY idcpDisciplinas, anoTurma; gives ... +--------+----------------------+-----------+-----------------+----------+ | ids | disciplina | mods | idcpDisciplinas | anoTurma | +--------+----------------------+-----------+-----------------+----------+ | 60 | Comunicação Visual | 134 | 49 | 10 | | 58, 59 | Comunicação Visual | 8599, 133 | 49 | 11 | +--------+----------------------+-----------+-----------------+----------+

Typically yes, that's what you see out on the net, but I would have to disagree with this method. IMO there is really only two common cases to use Try/Catch, that being the DB Connection and handling a duplicate constraint error. There is no need to litter the code base with Try/Catch blocks. (Yes, I was guilty of that until I got spanked by @Jacques1 and learned better) What "should" be done is set the PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION and let the exceptions bubble up and let PHP handle it, which it does very well. set_exception_handler can also be used if you want a custom handler for exceptions.

Actually, I think that Barand just made a small mistake, which is certainly very unusual for him The unique constraint should be: UNIQUE KEY `unq_page_link` (`user_id`, `page_link`), That will enforce uniqueness on a user/link basis, which is what I assume you are going for. This is a better solution in that you are using the db to enforce your integrity rule rather than relying on the front end code to do it for you. With that said, code around database queries needs to be written in a way that you catch and deal with database errors appropriately. Typically that is done with a try..catch block. I can't give you specifics without knowing in advance what db api you are using (mysqli vs pdo) . Here's an example out of the "(The only proper) PDO tutorial" which is highly recommended reading for anyone learning the PDO api: try { $pdo->prepare("INSERT INTO users VALUES (NULL,?,?,?,?)")->execute($data); } catch (PDOException $e) { $existingkey = "Integrity constraint violation: 1062 Duplicate entry"; if (strpos($e->getMessage(), $existingkey) !== FALSE) { // Take some action if there is a key constraint violation, i.e. duplicate name } else { throw $e; } } Assuming you are using PDO this could be adjusted to fit your problem as it is essentially the same issue you would face in dealing with the unique constraint violation to prevent a user from adding the same link multiple times. If you are using mysqli, then you should certainly read this. A general discussion of php error handling strategies is good to read. The important thing to note about this, is that you don't want to generalize error handling to try .. catch blocks around all your queries. This is a specific issue, having to do with something you expect to happen frequently. Lots of other database exceptions can happen, and you want to have a generalized exception handling solution for those.

Hi Barand, Amazing code and you only read a description of my bookmark profile. You are a 'helluva' coder. Your expertise and mastery shows in your replies. I don't really need to change anything that you have posted other than names but i didn't post to get free code. I am trying to learn from your example. I'm reading about sql now so that i can think better about these problems and approprite solutions. I'd like to come to the same conclusions as you oneday. I really learn alot from you and i thank you for that. Meantime, i've changed the last login code and it works well. I was actuly just inserting your login into lastlogin then inserting the current login into current login. I guess it is easier to say that login becomes your last login before i update the login. I guess i was thinking wrong here. Your idea is better. I don't have time to add the book mark code today. I have alot of things to do and i am behind schedule. I'll read more about sql before i go to bed, then tomorrow i will tackle this topic. I finished adding the bookmark profile to each page, so all i have to do now is submit it to the dbase. This code example is a great start! I also have to read the data from the db before i can display the bookmarks. I do not have so much coding experience as you do, so i am a bit slow. I'll update the post when i can finish this feature. I'll let you see the final code here so you can offer an opinion if you want to do so. Thank you, Barand, i have learned alot about sql today. You are steeringme in the right direction!