CREATE TABLE "classification_leadership_by_stage" (
  "stage" text,
  "winner" text,
  "general_classification" text,
  "points_classification" text,
  "mountains_classification" text,
  "young_rider_classification" text,
  "intergiro_classification" text,
  "trofeo_fast_team" text
);

Question: Who's the leader in the young rider classification in stage 12?
SQL: SELECT "young_rider_classification" FROM "classification_leadership_by_stage" WHERE "stage"='12';

Question: Who's leading in the general classification in stage 1a?
SQL: SELECT "general_classification" FROM "classification_leadership_by_stage" WHERE "stage"='1a';

Question: How many leaders are there in the intergiro classification in stage 20?
SQL: SELECT COUNT("intergiro_classification") FROM "classification_leadership_by_stage" WHERE "stage"='20';

Question: What's the leader team in the Trofeo Fast Team in stage 20?
SQL: SELECT "trofeo_fast_team" FROM "classification_leadership_by_stage" WHERE "stage"='20';

Question: Who's the winner in stage 1a, where the leader in the young rider classification is Francesco Casagrande?
SQL: SELECT "winner" FROM "classification_leadership_by_stage" WHERE "young_rider_classification"='Francesco Casagrande' AND "stage"='1a';

Question: Who's the leader in the general classification in stage 1a?
SQL: SELECT "general_classification" FROM "classification_leadership_by_stage" WHERE "stage"='1a';