SQL不在Linq中

Question

I have a (Oracle)SQL query that I want to translate to Linq to use on a NHibernate context. What the query does is to get me all the Functions that has been deleted from a given Module (ie. they don't exist in the given module but are linked to a predecessor Module )

"SELECT * FROM Function WHERE ModID = " + module.PredecessorID + "
   AND FncName NOT IN
      (SELECT FncName FROM Function WHERE ModId = " + module.ModID + " )"

Here is a image to explain the data model

I'm looking for an expression with the "dot notation", something like this:

DBContext.GetAll<Function>()
    .Where(x => x.Module.ModID == module.PredecessorID)...

Answer 1

You could do this in two steps (for readability).

var excludedNames = DbContext.GetAll<Function>()
                             .Where(x => x.ModeID == module.ModID)
                             .Select(x => x.FncName);

var result = DBContext.GetAll<Function>()
                      .Where(x => x.Module.ModID == module.PredecessorID &&
                                  !excludedNames.Contains(x.FncName));