If i have a infected industrial piercing will i have to take it or can i just take cephalexin?

Take it out!: Any foreign body will make it very difficult for your body to get rid of the infection. You need to remove any piercing hardware, allow the infection to heal, and then consider how badly you want a piercing there. Often the infection will heal without cephalexin once the hardware is out, but may need cephalexin (or other antibiotic if resistant staph germ) if it's been infected awhile.