SQL question

[jamesloi]

Hi

does anyone know if its possible to delete a specific row from a table?

thanks

[[deleted]]

lol

ofcourse it is possible, what would be the point of using a database if you couldn't remove any data from it?

[jamesloi]

yeh but i mean,

say i wanted to delete a record that was on row 4, could i delete that record without referencing its ID, or name etc.
bear in mind that row is not a field in the table.

[nnichols]

No. But why would you want to DELETE "row 4"? It is normal to want to DELETE a row based on certain criteria, not because of its location in the table.

[[deleted]]

"say i wanted to delete a record that was on row 4"

There is no 'row 4'. Databases have no rownumbers, just rows that contain data.
The order in which you see them depends entirely on the query.

"could i delete that record without referencing its ID, or name etc."

No, because if you do not reference any of it's content in any way, then there is no possible way to know which record you mean.

[jamesloi]

you must be wondering why i am trying to do this,
I have posted a topic on this forum called Delete query,
i am trying to delete records by Item_code which references
$itemcode using

$query = "DELETE FROM CD_data WHERE Item_code = '$itemcode'";

however this does not work as i think there is a problem because the Item_code field is an int, auto-increment, Primary key. there must be a problem with the databse recognising '$itemcode' because i have replaced this with a number and it works. but not woth $itemcode.

any ideas?
I think there is more explained on the post 'Delete query'
🙂

[[deleted]]

I bet the $itemcode comes from a FORM or a URL and you are using PHP 4.1+ and you forgot to use $GET['itemcode'] or $POST['itemcode'] instead...

[jamesloi]

Vincente,

i am using
$itemcode = $HTTP_POST_VARS['Item_Code'];

do i need to replace this with what you suggested
$GET['itemcode'] or $POST['itemcode']

becuse i have tried this and it still is not working?
😕

any help would be gratefully appreciated.

[[deleted]]

HTTP_POST_VARS was in use before PHP 4.1, as of 4.1 you should use the $POST and $GET equivalents.

Define 'not working' what is the error/problem?

[jamesloi]

Do i need something like

$GET['Item_code'] ;
$itemcode = "GET";

does this make sense? because i am a total beginner.
basically i am not getting any errors but it is just not deleting the record.🙁

[[deleted]]

If the record does not get deleted then there can be two things wrong:

1. The record does not exist

2. You didn't reference the right record.

3. is unlikely because you suppy the itemnumber in a previous script (I assume)

4. Is very likely.
   Make sure the query is correct by printing it before you execute it, a bit like:

<?
$sQuery = "DELETE FROM table WHERE itemcode = ".$_POST['item_code'];
echo $sQuery;
?>

Ofcourse this is only for when you use a form. If you use a URL to send the itemnumber, then you should use $GET instead of $POST.

You can always use the contents of $POST and $GET directly, you never have to copy the value to a new var or anything.

All vars you send through the URL end up in $GET, and all vars you send through a form end up in the $POST array.

[jamesloi]

vincente,

i tried what you said but the $_GET['Item_Code'] is printing nothing. Ive tried it with POST aswell.

'Item_Code' is the name for text box on the form.

im so fustrated. any more ideas dude🙁

[[deleted]]

Are you sure yo got the name right?

try adding this into your script and see exactly what you are sending to your script:

<?
echo '<pre>';
print_r($POST);
print_r($GET);
?>

[statrat]

what is the method of your form? it's probably POST right? then the textbox variable, if named 'Item_Code', should be $_POST['Item_Code']

try posting your entire script on the forum, form and all.

you have delete privileges?

[jamesloi]

I think $POST and $GET have not got any values as nothing appears apart from the usual ?!?

I have used the old $itemcode
$itemcode = $HTTP_POST_VARS['Item_Code'];

to print out the query and it prints it out correctly. But when it comes to executing the query it doesn't work. I have also tried changing the query to

$query = "DELETE FROM CD_data WHERE Item_code = "  . $itemcode;

but this gives me an error 1064: error in syntax

I feel like hurting my computer.:mad:

[nnichols]

$query = "DELETE FROM CD_data WHERE Item_code = '$itemcode'";

[jamesloi]

ive tried that nnichols.

[[deleted]]

and what if you print_r($HTTP_POST_VARS)

The error you get seems to be because $itemcode is empty.

[jamesloi]

It prints this out

Array ( [Sub] => Remove CD [Item_Code] => 54 )

54 is the number i put into the text box.
I dont know why it is not entering this into the query.

[[deleted]]

IS the query built inside a function?