Posted by Juliette on 07/16/06 04:02

mindwarp wrote:
> Hi,
>
> When a user submits / posts data my php script Inserts data into my
> database.
> If they refresh the script or click back and click submit again I get
> duplicate record.
>
> Is there an easy solution to this?
>
> Or do I need to create a hidden field which contains some sort of
> unquie data, like a time stamp and have a have a unique field which
> stops it adding the record?
>
> Best regards,
>
> Jules.
>


You could for instance:

a) test the values received against the database before inserting, i.e.
do a SELECT count(*) FROM table WHERE field1=$_POST[field1] AND
field2=$_POST[field2] ...

If the count if 1 or more, give an error message to the user and don't
insert.

b) make one or a combination of fields in your table unique which should
make the insert fail. Be careful which combination you choose.


Having a unique field in your table is always a good idea. Normally this
would be a record-id field which auto-increments. This however will not
prevent duplicate records from being entered as each record gets a new
unique auto-incremented id.

Having a timestamp as a unique field does not sound like a good idea.
What about two users opening the same form page at the exact same moment
? (depending on how busy your site is, probably a very rare occurance,
but still)
It could work if your site does not have large volumes of traffic, but
it is not a stable solution.

Good luck,
Juliette

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