Name the motogp winner for 6 may
CREATE TABLE "grands_prix" (
  "round" real,
  "date" text,
  "grand_prix" text,
  "circuit" text,
  "moto_gp_winner" text,
  "moto2_winner" text,
  "moto3_winner" text,
  "report" text
);
SELECT "moto_gp_winner" FROM "grands_prix" WHERE "date"='6 May';