CREATE TABLE "nfl_draft" (
  "round" real,
  "pick" real,
  "player" text,
  "position" text,
  "school_club_team" text
);

Question: Name the Round which has a Position of defensive back and a Pick of 226?
SQL: SELECT MIN("round") FROM "nfl_draft" WHERE "position"='defensive back' AND "pick"=226;

Question: Name the Round which has a Player of zack walz?
SQL: SELECT "round" FROM "nfl_draft" WHERE "player"='zack walz';

Question: Name the Round which has a Position of defensive back and corey chavous?
SQL: SELECT MIN("round") FROM "nfl_draft" WHERE "position"='defensive back' AND "player"='corey chavous';

Question: Name all Pick that has a Round of 7, and a School/Club Team of arizona st.?
SQL: SELECT COUNT("pick") FROM "nfl_draft" WHERE "round"=7 AND "school_club_team"='arizona st.';