How to test null recordset value 2

[clivehenderson]

Hi
I've just managed to create a joined recordset with a mixture of values and nulls in the recordset fields.
This was my intention and I now need to be able to test if field has a null value null value for example


if (@$row_rsCourt1['bookingID'] = null) {
?>
<span class="courtFree">FREE</span>
<?php
// else Conditional region1
} else { ?>
<span class="courtBooked">BOOKED</span>
<?php }
The 'else' part of the statement is always executed.

I've tried concatenating the nullfield with a letter but it still returns a null value

Not sure what else to do

Appreciate any help on this
kind regards
Clive

 

[feherke]

Hi

I now need to be able to test if field has a null value

[b]select[/b] [teal]*[/teal] [b]from[/b] table [b]where[/b] field [highlight][b]is[/b] [b]null[/b][/highlight][teal];[/teal]

I've tried concatenating the nullfield with a letter but it still returns a null value

[b]select[/b] concat[teal]([/teal][highlight]coalesce[teal]([/teal][/highlight]field[highlight][teal],[/teal][green][i]''[/i][/green][teal])[/teal][/highlight][teal],[/teal][green][i]'letter'[/i][/green][teal])[/teal] [b]from[/b] table[teal];[/teal]

By the way, what kind of SQL ?

By the way, how is this related to PHP ?

Two advices :

if (@$row_rsCourt1['bookingID'] = null) {

[ul]
[li]Add the [tt]@[/tt] operator only after you are sure your code is correct and functional.[/li]
[li]Setting a variable to [tt]null[/tt] will be always evaluated to false. ( The equality test operator is [tt]==[/tt] . )[/li]
[/ul]


Feherke.

http://free.rootshell.be/~feherke/

 

[alan92rttt]

If your using mySql

http://dev.mysql.com/doc/refman/4.1/en/control-flow-functions.html#function_ifnull

select ifnull(bookingID,0) as bookingID from ....


To do it in PHP

http://www.php.net/manual/en/function.is-null.php

if((is_null(@$row_rsCourt1['bookingID'])?0,@$row_rsCourt1['bookingID'])!=0)
{
?>
<span class="courtFree">FREE</span>
<?php
// else Conditional region1
} else { ?>
<span class="courtBooked">BOOKED</span>
<?php }