I was contracted to build an on-line knowledge base that searches and cross-references many thousands of replacement parts for a niche industry. My client furnishes this app to his customers on a subscription basis.

It uses MySQL and PHP and it works great. I want to deploy it in "demo mode" to sell my skills. I want the user to see the functions, but I have to guard the data for my client.

My first idea was to obfuscate the results. That's at cross-purposes with showing how well it searches. I'm considering a limit on how many searches you can perform, but that's awkward too as someone could visit every day and get more answers than we would prefer.

Other posts I've found are about letting people interact with an app, but without the challenge of protecting a big knowledge base.

Can you suggest an approach? (Note, I put the tag obfuscation, but not sure it applies because java code obfuscation seems to be unrelated.)