Prevent entering duplicate records to mysql table

[phopman]

Hi there!

Since this is my first post, I'll try to be gentle with you :-)

I have a script that goes like this:

Connect to db. select data from db, and list up (only one variable, text).

I also have a form so I can insert into the database (insert into table where $id = contentid).

How can I check in php, if it is already there?

My code is something like this:

            $id = intval( mysql_real_escape_string($_GET['id']));
            $as_text = addslashes($_POST['text']);
            $tr_text = trim($as_text);
                $query = "INSERT INTO jos_issues(ID,text,contentid)
                    VALUES(NULL,'$tr_text','$id')";
            $result = mysql_query($query);
 

How can I easily check if it has already been inserted into the database?

the table consists of 3 columns; id, text and contentid.
contentid is used so I can list all text that is connected to one particular content.

So, now I've been gentle with you, so you can be gentle with me :-)


Phopman

[ak1dnar]

Welcome to TheScripts.com

Your "ID" column is an auto increment field correct?
Then no Need to insert a Null value to it. remove it first.

And back to the question, As I feel you are trying to prevent entering duplicate records to the table.
But when you need it to check? in other words, duplicate entries could be store to the table when pressing refresh button after inserting record(when on the same page) or is it any other instance?

[phopman]

Welcome to TheScripts.com

Your "ID" column is an auto increment field correct?
Then no Need to insert a Null value to it. remove it first.

And back to the question, As I feel you are trying to prevent entering duplicate records to the table.
But when you need it to check? in other words, duplicate entries could be store to the table when pressing refresh button after inserting record(when on the same page) or is it any other instance?

I am trying to prevent duplicate records. one text (ex. 'Heidi',
belongs only to one contentID.

I need to check whenever someone press submit after filling out the form, or whenever someone press refresh button.

How do I do that? do you have any simple examples of this problem? I couldn't find any good examples on google.com, but I don't think I am the first one with a problem like this.


Phopman

[ak1dnar]

There were few threads on the site, I'm sure. I'll try to find out one for you. keep posting with your updates, then more experts comes to the thread. Please use the site search tool to find out.

Thread Title changed to match with the question:
Update delete and a select from db php. How?

[pbmods]

Heya, Phopman.

Try using REPLACE instead of INSERT.

REPLACE will automatically remove the conflicting row if it exists before INSERTing the new data.

[phopman]

Thanks for the tips. It works like a charm!

[pbmods]

Heya, Phopman.

Glad to hear you got it working! Good luck with your project, and if you ever need anything, post back anytime :)

[phopman]

Will do!

I just found this forum, and I hope I can contribute more in time than I am doing now.

Real friendly forum with nice people it seems.

You are people and not computers? :-)

[pbmods]

I'm sorry, Dave.

I'm afraid I can't answer that.

[phopman]

What are you talking about, HAL?