Aug 12, 2016 12:43 PM|PatriceSc|LINK
You can use abc.ToString() to get the underlying SQL for a query.
Here they basically check if the parameter is populated to take into account if it is but to ignore it if it is not. You can also "compose" queries ie something such as :
Each where clause "enrich" the current clause. At the end it allows to have a SQL statement that really just include what you need/want