Adds the projection of a query for the specified alias to the mappings. This is useful when we've a SetReferenceExpression which refers to a set with an alias and we need to obtain its projection (which is all we need from the referenced set anyway, the rest is already in the SetReferenceExpression.

public void AddQueryProjectionForAlias(
	ProjectionExpression toAdd,
	SetAlias alias
)

Public Sub AddQueryProjectionForAlias ( 
	toAdd As ProjectionExpression,
	alias As SetAlias
)