PHP Check for NULL

Question

Here is the below Code:

$query = mysql_query("SELECT * FROM tablex");

if ($result = mysql_fetch_array($query)){

    if ($result['column'] == NULL) { print "<input type='checkbox' />"; }
    else { print "<input type='checkbox' checked />"; }
}

If the values are NOT NULL i still get the uncheked box. Am i doing something wrong from above, shoudnt $result['column'] == NULL work?

Any Ideas?

Solution 1

Use is_null or === operator.

is_null($result['column'])

$result['column'] === NULL

Solution 2

How about using

if (empty($result['column']))

Solution 3

Make sure that the value of the column is really NULL and not an empty string or 0.

Solution 4

I think you want to use

mysql_fetch_assoc($query)

rather than

mysql_fetch_row($query)

The latter returns an normal array index by integers, whereas the former returns an associative array, index by the field names.

View more solutions

Comments

[Scott Evernden]

is that really your code? you have a coding error and probably an error_log file

[Angel.King.47]

Im simply printing the checkbox. And its checked if the value is not null. It dosent seem to do that.. Hense it always goes into the first if statment

[Scott Evernden]

the code posted is missing a right paren and a right brace and i get down-voted for spotting that? eyeroll

[Angel.King.47]

Sry this might sound mean.. But i didnt ask for syntax problems.. I asked for the Null value.. And if there was syntax error.. the code will output the error. However said that i did see the bracket.. I didnt actually copy and paste my code.. it was more of a type it my self. PS it wasnt me who downvoted you :D

[Angel.King.47]

sry im using mysql_fetch_array()... put the wrong one in.. Editing now

[Angel.King.47]

i had results in two places... Its late and my brain is blown up.. Exactly what i did to figure it out :D

[Anthony Rutledge]

Using PHP's empty() function leaves too much room for interpretation (php.net/manual/en/function.empty.php) and is more of a language specific solution to a general programming scenario. If he uses ===, he will have a solution that he can use in many languages.

[Anthony Rutledge]

That's why fernyb's answer is not a preferable solution.

[Zoran]

This is not correct because if filed may be null application may have different meaning for the field for example null may represent not checked and 0 false and 1 true

[Adam]

empty also returns true if column is 0

[Andris]

$result['column'] === NULL did not work. Worked is_null($result['column']). Php version 7.0.