Question

I’m trying to call $row (database array) from within a function but calling the column name based on a variable.

Here is the full code… You can see the results at

http://tlcs.stuart-pinfold.co.uk/test.php?id=20

and

http://tlcs.stuart-pinfold.co.uk/test.php?id=21

<?php
include("includes/db.php"); // includes all the db connections

$id = $_GET['id'];

$sql = "SELECT * FROM users WHERE UserID='".$id."'";
$set = mysql_query($sql);
$row = mysql_fetch_array($set);

function checkAvailability($day)
{
 $check = "UserCommute".$day;
 if($row[$check]=="1")
 {
  echo '<img src="/tick.jpg" alt="Available on this day" />';
 }
 else
 {
  echo '<img src="/cross.jpg" alt="Not available on this day" />';
 }
 echo " = ".$check."<br/>";
}

echo "Full Name:<br/>".$row['UserFullName']; // this works perfectly

echo "<br/><br/>Using the function...<br/>";

echo checkAvailability('Mon');
echo checkAvailability('Tue');
echo checkAvailability('Wed');
echo checkAvailability('Thu');
echo checkAvailability('Fri');
echo checkAvailability('Sat');
echo checkAvailability('Sun'); // these always return a cross even when the database entry is 1

echo "<br/>Using hard-coded row values...<br/>";

echo $row['UserCommuteMon']." = UserCommuteMon<br/>";
echo $row['UserCommuteTue']." = UserCommuteTue<br/>";
echo $row['UserCommuteWed']." = UserCommuteWed<br/>";
echo $row['UserCommuteThu']." = UserCommuteThu<br/>";
echo $row['UserCommuteFri']." = UserCommuteFri<br/>";
echo $row['UserCommuteSat']." = UserCommuteSat<br/>";
echo $row['UserCommuteSun']." = UserCommuteSun<br/>"; // these work perfectly, returning 0s or 1s, matching the database

?>

It only returns crosses, never ticks.

Where am I going wrong?

Answer 1

You’re defining a function, inside the function there is no scope of $row.

Either define a new query there that will check if the user is available on a given day or remove the function and compare the field without the function.

So instead of doing checkAvailability('Mon'); do:

if($row["UserCommuteMon"] === 1) {

}

or give $row to your function. Like checkAvailability($row, 'Mon');

And remember to clean your $_GET['id'] to prevent SQL-injections.