troubleshooting Question

Why is my defined string not being up by my function further down in my code?

Avatar of Adam
AdamFlag for United Kingdom of Great Britain and Northern Ireland asked on
DatabasesWeb DevelopmentHTMLPHP* HTML 5
10 Comments1 Solution133 ViewsLast Modified:
Hello all,

I have a line in my code which checks to see if the email value entered in a submitted form already exists in the database. If so,  a value of 0 or 1 is assigned to a string and the string value is displayed.

$select = mysqli_query($db_connection, "SELECT `email` FROM `teachers_table` WHERE `email` = '".$_POST['email']."'") or exit(mysqli_error($db_connection));
	if(mysqli_num_rows($select)) {
    $email_exists = '1';
		$email_exists = '0';
		echo $email_exists;

This part seems to work as intended - at least the value of 0 or 1 is displayed correctly depending on whether the email exists in the database or not. The next part of my code calls another function, (which in turn calls another validation function) which displays errors.

The validation worked but I added to it:
	if($email_exists == '1') {
      $errors[] = "EMAIL Exists IN OUR DATABASE";

However, when I do this, I get an  Undefined variable: email_exists in... notice / error.

I don't understand why this is coming up as not defined if the function is being called after I have defined this value.  The error message is displayed even though I can see the value of $email_exists (i.e. the 1 or 0) output in the screen.

I've tried removing the quotes, changing to single quotes and using TRUE and FALSE but this didn't appear to change anything.

 When I use '=' instead of '==' i.e:
if($email_exists = '1') {
      $errors[] = "EMAIL Exists IN OUR DATABASE";

...the not defined error goes away but the logic doesn't work, in that $email_exists seems to be always 1 and the error EMAIL Exists IN OUR DATABASE is always displayed.

Any help, as always, much appreciated.

Many thanks,


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