database_update_script_idempotent_external_dependency.sql

-- the following external database with new prices should have ben created before execution of this script
/*
CREATE TABLE tmpProductPrices
(
  ProductId int
  , Price number(10,2)
)
*/

UPDATE p
SET p.Price = tmp.Price
FROM Products AS p
INNER JOIN tmpProductPrices as tmp
   ON p.ProductId = tmp.ProductId