Problem with some codes

Hello

Can you help me please..

Here's some PHP code :
// in a while process

$value="";

$reqt = mysql_query("select value from table where ref='$xxx'");

$value = mysql_result($reqt,0,"value");


$ok="0";

if ($value=="0"){

echo "$value";

$ok="1";

}

Normally only when value = 0 , ok = 1

but when i execute this script and when the sql doesn't return any fields

the ok=1 when value from sql = nothing (any fields returned)

i hope i'm clear :)

nobody can help me?

"Nico" <nico-bc@belcenter.com> a écrit dans le message de news:
45228ce7$1@ns2.belcenter.be...
> Hello
>
> Can you help me please..
>
> Here's some PHP code :
> // in a while process
>
> $value="";
>
> $reqt = mysql_query("select value from table where ref='$xxx'");
>
> $value = mysql_result($reqt,0,"value");
>
>
> $ok="0";
>
> if ($value=="0"){
>
> echo "$value";
>
> $ok="1";
>
> }
>
> Normally only when value = 0 , ok = 1
>
> but when i execute this script and when the sql doesn't return any fields
>
> the ok=1 when value from sql = nothing (any fields returned)
>
> i hope i'm clear :)
>
>
>
>

Nico wrote:
> Hello
>
> Can you help me please..
>
> Here's some PHP code :
> // in a while process
>
> $value="";
>
> $reqt = mysql_query("select value from table where ref='$xxx'");
>
> $value = mysql_result($reqt,0,"value");
>
>
> $ok="0";
>
> if ($value=="0"){
>
> echo "$value";
>
> $ok="1";
>
> }
>
> Normally only when value = 0 , ok = 1
>
> but when i execute this script and when the sql doesn't return any fields
>
> the ok=1 when value from sql = nothing (any fields returned)
>
> i hope i'm clear :)

This is happening because "0", is equivalent to FALSE and, I believe,
NULL, in PHP.
When your query returns no values, it is returning a value equivalent
to a 0.

There are two ways to try getting around this. The first, I'm not
certain will work, but you can try anyway.
- use '===' instead of '==' in your if statement. '===' tests for
equality and that the compared values are of the same type.
- check the number of rows returned with mysql_num_rows, then only echo
the variable if >0

i've found a workaround:
i used
if ($value != "" and $value=="0"){
}

works :)
because when sql doesn't return any values
$values = "" :-)

<mootmail-googlegroups@yahoo.com> a écrit dans le message de news:
1159993017.064199.264780@e3g2000cwe.googlegroups.c om...
> Nico wrote:
>> Hello
>>
>> Can you help me please..
>>
>> Here's some PHP code :
>> // in a while process
>>
>> $value="";
>>
>> $reqt = mysql_query("select value from table where ref='$xxx'");
>>
>> $value = mysql_result($reqt,0,"value");
>>
>>
>> $ok="0";
>>
>> if ($value=="0"){
>>
>> echo "$value";
>>
>> $ok="1";
>>
>> }
>>
>> Normally only when value = 0 , ok = 1
>>
>> but when i execute this script and when the sql doesn't return any fields
>>
>> the ok=1 when value from sql = nothing (any fields returned)
>>
>> i hope i'm clear :)
>
> This is happening because "0", is equivalent to FALSE and, I believe,
> NULL, in PHP.
> When your query returns no values, it is returning a value equivalent
> to a 0.
>
> There are two ways to try getting around this. The first, I'm not
> certain will work, but you can try anyway.
> - use '===' instead of '==' in your if statement. '===' tests for
> equality and that the compared values are of the same type.
> - check the number of rows returned with mysql_num_rows, then only echo
> the variable if >0
>