Lighting, Light Fixtures, Ceiling and Exhaust Fans - Flood light, motion and on demand

I want to install a motion detecter flood light but also want to be able to turn and leave it on on demand with a wall switch. Are any made this way or would I have to make wiring bypass mods?

Yes, many if not most of these fixtures have various forms of override so that you can force it to be on all the time until manually turned off, off all the time until manually turned on, or under the full control of the motion sensor and/or light sensor. The on-all-the-time override usually involves some sequence of flipping the switch on/off/on in rapid sequence. Some of these fixtures have a restriction that there only be one fixture on one switch, so read the instructions carefully if you plan more than one fixture.