/* Transformation - There is really no SQL Equivalent here.*/

//Project
//Here you are saying transform one record set to another by
//applying a transformation on each record
Product clean(Product inrec) := TRANSFORM
  SELF.productName := Std.Str.ToUpperCase(inrec.productName);
  SELF := inrec;
END;

upperProducts := PROJECT(products, clean(LEFT));

OUTPUT(upperProducts);

//Iterate
//Here you are saying transform one record set to another by
//applying a transformation on a pair of records at a time
Product doCompute(Product l, Product r) := TRANSFORM
  SELF.quantityInStock := IF(l.productVendor=r.productVendor,
           l.quantityInStock + r.quantityInStock, 0);
  SELF.productVendor := R.productVendor;
  SELF := l;
END;

productsByVendorDS := SORT(products, productVendor);
vendorQtyDS := ITERATE(productsByVendorDS, doCompute(LEFT, RIGHT));


OUTPUT(vendorQtyDS);

//ROLLUP
//Here you are saying transform one record set to another by
//deduping and transforming the matching records during the
//dedup process
Product doRollup(Product l, Product r) := TRANSFORM
  SELF.quantityInStock := IF(l.quantityInStock > r.quantityInStock,
           l.quantityInStock, r.quantityInStock);
  SELF := l;
END;

rolledUpDS := ROLLUP(vendorQtyDS,
      LEFT.productVendor=RIGHT.productVendor,
      doRollup(LEFT, RIGHT));

OUTPUT(rolledUpDS);