What is the average silver for a rank less than 8, were there were no more than 4 bronze and 12 in total?
CREATE TABLE "sporting_events" (
  "rank" real,
  "nation" text,
  "gold" real,
  "silver" real,
  "bronze" real,
  "total" real
);
SELECT AVG("silver") FROM "sporting_events" WHERE "rank"<8 AND "total"=12 AND "bronze"<4;