Regex: only alphanumeric but not if this is pure numeric

Question

For instance:

\'1\'     => NG
\'243\'   => NG
\'1av\'   => OK
\'pRo\'   => OK
\'123k%\' => NG

I tried with

Answer 1

Try this: ^[a-zA-Z0-9]*[a-zA-Z]+[a-zA-Z0-9]*$