CREATE TABLE "classification_leadership" (
  "stage" real,
  "winner" text,
  "general_classification" text,
  "points_classification" text,
  "mountains_classification" text,
  "combination_classification" text,
  "team_classification" text
);

Question: How many winners were there when the mountains classification was not awarded? 
SQL: SELECT COUNT("winner") FROM "classification_leadership" WHERE "mountains_classification"='not awarded';

Question: Who was awarded mountains classifications when Mikel Nieve was the winner? 
SQL: SELECT "mountains_classification" FROM "classification_leadership" WHERE "winner"='Mikel Nieve';

Question: Who was awarded mountains classification when Alessandro petacchi won? 
SQL: SELECT "mountains_classification" FROM "classification_leadership" WHERE "winner"='Alessandro Petacchi';