How many hit records did Dragnet inspire ?

While I really have no idea, and do not even know your definition of "Hit Record," I do remember a comedy record by Stan Freeburg, "St. George and the Dragnet.' In it, St. George sounded a lot like Sgt. Joe Friday as he used his detective's powers to find the dragon.

That's one of them DG.

Ray Anthony released a popular
version of the "Dragnet Theme".
In fact, it was so popular that
a plagiarism suit was filed
against Walter Schumann (who wrote
the distinctive 4 note opening
theme) by Miklos Rozsa, claiming
that part was taken from his
theme "Danger Ahead" written for
the film The Killers. Rozsa
won the suit and the rights to
the royalties of the music!