if the double bass were fretted like its electric cousin how many frets would it have, what im trying to say is how mant "frets" does a db have?
Frets are not determined by the scale length, so the number of frets on a 42" scale double bass could be no different than the number of a 34" scale electric bass. If you had "frets" on an imaginary fingerboard from the nut to the bridge, both instruments would have the same number of frets. Fingerboard lengths vary among double basses, just as they do with electric basses. My Kay (non-original fingerboard) has 28 positions, or "frets" if they existed. Maybe that answers your question.
The number of frets is not determined by the scale length, but the fret spacing is. THe number of frets is based on how much room you have given the spacing determined by scale. I use a little program called "Fret Specs" for determining measurements on my instruments. Works well. There are plenty of fret calculators out there for free though. Fret Spacings For 42.0 Scale Length 24 Frets FRET In REMAINDER #1 2.357 39.643 #2 2.225 37.418 #3 2.100 35.318 #4 1.982 33.336 #5 1.871 31.465 #6 1.766 29.699 #7 1.667 28.032 #8 1.573 26.459 #9 1.485 24.974 #10 1.402 23.572 #11 1.323 22.249 #12 1.249 210000 #13 1.179 19.821 #14 1.112 18.709 #15 1.050 17.659 #16 0.991 16.668 #17 0.936 15.732 #18 0.883 14.849 #19 0.833 14.016 #20 0.787 13.229 #21 0.742 12.487 #22 0.701 11.786 #23 0.662 11.124 #24 0.624 10.500