Converting string to a numeric type

[Anon]

Is there a way of converting a string that contains only numbers to a numeric type?

Im trying to execute the following SQL and I get nothing ($student_exam_number contains a 1 and is passed from $PHP_SELF and then to this script by the post method to execute the SQL with MYSQL)

select * from question_table where exam_id = $student_exam_number

however

select * from question_table where exam_id = 1

works.

I tried

if (is_string ($student_exam_number))
{
echo "string";
}

and It always is string.

Is there a PHP Version 3.0.12 function that will help me out or is there something I can do with MYSQL Version 3.22.27 ?

When I do a PHPINFO here is what the HTTP_POST_VARS is: HTTP_POST_VARS["student_exam_number"] s%3A1%3A%222%22%3B

All my other numerics are fine. TIA

[Anon]

String conversion ca be done by using settype function.

settype ($student_exam_number, "integer");

Settype returns true if conversion is successfull.

if (settype ($student_exam_number, "integer))
{ echo ("Conversion succeeded.");
} else {
echo ("Coversion error.");
}

[trellie]

basically in php you do not need to do type-juggling... it will automatically do so.

and in your example it should work...

$sql="select * from question_table where exam_id = $student_exam_number";

this will definitly work if $student_exam_number contains only '1'...

[Anon]

hi,

the solns given above are good enough, but there is another method also.

since php automatically sets the type, just increment and decrement the no. once

eg. if $i is string, just put these two lines in your page

$i++;
$i--;

done! your variable is type set to integer

steve