Question

I want to prevent an empty value from going into a MySQL database

I’m using following but for some reason it is letting the empty values get through…

if (trim($var)= '' || !isset($var)){
header("Location:page.php?er=novariablel");
}
else {
...insert into database
}

Note, there is a bunch of complicated stuff that sets the value of var which is why I want to have both the ='' and the !isset because either might be the case.

Am I missing something with the or statement, i.e. it evaluates to false if both are true. Or what am I doing wrong?

Answer 1

Try:

if (!isset($var) || empty(trim($var))){

empty() is a better way to check to see if a variable has no value. Just keep in mind that the following will return true:

The following things are considered to be empty:

• "" (an empty string)
• 0 (0 as an integer)
• 0.0 (0 as a float)
• "0" (0 as a string)
• NULL
• FALSE
• array() (an empty array)
• var $var; (a variable declared, but without a value in a class)