text: ALTER TABLE "machines" DROP CONSTRAINT IF EXISTS "machines_fk0";
  
  ALTER TABLE "collections" DROP CONSTRAINT IF EXISTS "collections_fk0";
  
  ALTER TABLE "units" DROP CONSTRAINT IF EXISTS "units_fk0";
  
  DROP TABLE IF EXISTS "machines";
  
  DROP TABLE IF EXISTS "collections";
  
  DROP TABLE IF EXISTS "collection to units";
  
  DROP TABLE IF EXISTS "units";
  
  