How to process SQL query correctly?

Question

PHP

Good day to all!
There is

$id = mysql_result($res,0,"id") or die(mysql_error());

0 can also be returned from the base, but die(mysql_error()) is selected in this one. How to avoid this and correctly handle 0 if it was given to the database?
Thanks in advance for your reply!

Answer 1

Some people say that I'm nervous.
Well, how can you not be nervous when you see such a monkey * code, the focus of sin and vice?
Well, how can you manage to make SO many mistakes in one line?
Guga, my boy. If you continue to write all this, then you will go to hell.
Here, see how to actually process the SQL query correctly:

$stmt = $pdo->prepare("SELECT id FROM users WHERE email =?");
$stmt->execute([$email]);
$id = $stmt->fetchColumn();

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* from the word "monkey", i.e. repeating certain actions without understanding their meaning.