DROP VIEW "cancion_principal";
--> statement-breakpoint
ALTER TABLE "cancion" DROP CONSTRAINT "cancion_muestra_id_medio_id_fk";
--> statement-breakpoint
ALTER TABLE "cancion" DROP COLUMN "muestra_id";
--> statement-breakpoint
CREATE VIEW "cancion_principal" AS
  SELECT * FROM "cancion" WHERE "version_de_id" IS NULL;
--> statement-breakpoint
DELETE FROM "medio" AS m
WHERE m."clase" = 'muestra'
  AND m."clave" LIKE 'muestras/%'
  AND NOT EXISTS (
    SELECT 1 FROM "instrumento" AS i WHERE i."muestra_id" = m."id"
  );