Duplicate records added from post forms, easy solutions?

[mindwarp]

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.

[Alvaro G. Vicario]

Re: Duplicate records added from post forms, easy solutions?

*** mindwarp escribió/wrote (15 Jul 2006 02:31:04 -0700):

If they refresh the script or click back and click submit again I get
duplicate record.
>
Is there an easy solution to this?

This simpliest solution is to move user away from insert script. After
inserting data you can use header() to send a "Location" header and
redirect user to another page (which can be even the same, but with an
empty form).

Of course, this is not bulletproof but should be enough.


--
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--

[Juliette]

Re: Duplicate records added from post forms, easy solutions?

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

[Jerry Stuckle]

Re: Duplicate records added from post forms, easy solutions?

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 also set a session variable indicating the record had been
added.

--
=============== ===
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex@attgl obal.net
=============== ===

[Sheldon Glickler]

Re: Duplicate records added from post forms, easy solutions?

"mindwarp" <mindwarpltd@gm ail.comwrote in message
news:1152955864 .173058.229680@ p79g2000cwp.goo glegroups.com.. .

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?

Generally I have a primary key and the "WHERE" clause prevents duplicates.
However, to avoid errors you could check first for its existence and the
either ignore it, send a message, or do an UPDATE.

Shelly

[rik.catlow@gmail.com]

Re: Duplicate records added from post forms, easy solutions?

You can add an if to check the database if the has the record already.

$query_check = "SELECT * FROM `contest` WHERE record='$record '";
$query = @mysql_query($q uery_check) or die("Could not check for
account in our database.");

if (mysql_num_rows ($query) 0) {
$rv echo "That record is already in the database";
}

Well something like that...



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.

[s a n j a y]

Re: Duplicate records added from post forms, easy solutions?

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.
>

I would go with what Jerry said. Set a session variable indicating that
insertion has been done. If user tries to repost, check for existence of
the variable and just escape all the insertion code.

[Juliette]

Re: Duplicate records added from post forms, easy solutions?

s a n j a y wrote:

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.
>>

>
I would go with what Jerry said. Set a session variable indicating that
insertion has been done. If user tries to repost, check for existence of
the variable and just escape all the insertion code.

I wouldn't advice that as that would also exclude a user from posting
*something else* using the same form.

[Jerry Stuckle]

Re: Duplicate records added from post forms, easy solutions?

Juliette wrote:

s a n j a y wrote:
>

>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.
>>>

>>
>I would go with what Jerry said. Set a session variable indicating
>that insertion has been done. If user tries to repost, check for
>existence of the variable and just escape all the insertion code.

>
>
>
I wouldn't advice that as that would also exclude a user from posting
*something else* using the same form.

Why? When the form is first displayed, clear the session variable.
Then when the form is submitted, set the variable.

Pretty standard programming.

--
=============== ===
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex@attgl obal.net
=============== ===