CREATE TABLE "classification_leadership_by_stage" (
  "stage" text,
  "winner" text,
  "general_classification" text,
  "points_classification" text,
  "mountains_classification" text,
  "team_classification" text
);

Question: What is the general classification of Mapei-clas in stage 12?
SQL: SELECT "general_classification" FROM "classification_leadership_by_stage" WHERE "team_classification"='mapei-clas' AND "stage"='12';

Question: Which winner has a P stage?
SQL: SELECT "winner" FROM "classification_leadership_by_stage" WHERE "stage"='p';

Question: Which stage corresponds to Banesto and Tony Rominger?
SQL: SELECT "stage" FROM "classification_leadership_by_stage" WHERE "team_classification"='banesto' AND "points_classification"='tony rominger';