Using custom field content as expression in IF statement [closed]

I asked the question in another group and here I got an answer that has turned out to be useful.

BE AWARE! It must be dealt with with caution as the PHP eval() function can be a significant security risk.

Find the answer here:
https://stackoverflow.com/a/55518496/11309498

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)