Which Total Apps (sub) has 6 goals total?
CREATE TABLE "playing_career_statistics" (
  "season" text,
  "league_apps_sub" text,
  "league_goals" text,
  "cup_apps_sub" text,
  "cup_goals" text,
  "total_apps_sub" text,
  "total_goals" text
);
SELECT "total_apps_sub" FROM "playing_career_statistics" WHERE "total_goals"='6';