How to compare API key correctly?

Question

PHP

Currently implemented as follows:

$request = "SELECT APIKey, FullName FROM users WHERE UserName = '$USER_NAME'";

if((isset($rs->APIKey) && !empty($rs->APIKey)) && (decrypt($rs->APIKey) == $API_KEY))
{
}

Question: Why not use $encAPIKey = encrypt($API_KEY)and substitute it in the SQL query:

$request = "SELECT APIKey, FullName FROM users WHERE UserName = '$USER_NAME' AND APIKey = '$encAPIKey'";

Perhaps I don’t understand something and there are some moments of security violations, etc.?

Answer 1

Q: Why not use

Firstly, this way you will not know what the reason is - in the login or in the password, or in both fields. Secondly, it MAY work with keys, but it doesn’t work like that with passwords, there is a different reconciliation algorithm, and it is advisable not to produce entities and create algorithms that are as close as possible in implementation in similar places.