One of the ways you can make your queries more flexible is by passing it some parameters. For example, suppose that you want to list the films that belong to a given category and you have that category in a properties file. If the category in your file is Comedy, the query to run will look as follows:
SELECT f.title FROM public.film f JOIN public.film_category fc ON f.film_id = fc.film_id JOIN public.category ca ON fc.category_id = ca.category_idWHERE ca.name = 'Comedy';
In your Transformation, you want to replace Comedy with a parameter, so the category changes according to the content of your file. This is done in two parts:
- You have to prepare a stream with the parameter(s) that the query will receive ...