CREATE TABLE "b" (
  "player" text,
  "pos" text,
  "from" real,
  "school_country" text,
  "rebs" real,
  "asts" real
);

Question: when did asts reach 0?
SQL: SELECT "from" FROM "b" WHERE "asts"=0;

Question: beyond 2001, what is the lowest asts from a pos of sf?
SQL: SELECT MIN("asts") FROM "b" WHERE "pos"='sf' AND "from">2001;