How to find general solution (in terms of parameters) for diofantine equations x^2+y^2-z^2=1 and x^2+y^2-z^2=-1?

It's easy to find such solutions for x^2+y^2-z^2=0 or x^2+y^2-z^2-w^2=0 or x^2+y^2+z^2-w^2=0, but for these ones I cannot find anything relevant.

Victor Kuliamin