Find empty strings in parameters

Background

Sometimes users can define empty strings in Parameters. This can cause problems when calculating. Therefore it is necessary to find empty strings in Parameters.

Solution

Get the data field from the Parameters in to a table and apply the Formula Operator.
For a parameter named par_WHERE1_ADD_MANUAL
apply

#par_WHERE1_ADD_MANUAL# == null ? "xxxx": (((string)#par_WHERE1_ADD_MANUAL#).Trim() == "" ? "yyy": "ok")

So if the Parameter is a Null Value then xxxx is returned, if it is an empty string then yyy is returned, if everything is fine, then ok is returned.