geometry SRID mismatch is different from coincident points. Keep both identifiers beside the distance and preserve the distinction between NULL and zero.
SQUARE: Expect a float Result From Numeric Inputs
SQUARE accepts numeric inputs convertible to float and returns float. Explicit decimal display keeps this small example readable without claiming exact decimal multiplication.
SQRT: Keep Fractional Roots in the Result
SQRT produces an approximate square root. These read-only examples preserve fractional roots, state the display precision and distinguish a missing input from zero.