You probably found out that you can’t join an Entity Framework LINQ query with a local list of entity objects, because it can’t be translated into SQL. I would preselect the database data on the account numbers only and then join in memory. var accountNumbers = lstFarmerProfiles.Select(x => x.AccountNo).ToArray(); var duplicationChecklist = from profile in … Read more
This problem is normally caused by a failure in type inference from in the expression provided to the Where statement. As was mentioned in the comments above it is 100% caused by the assignment operator in the lambda returning an int instead of a bool. To be clear – where you have var result = … Read more
from item in db.vw_Dropship_OrderItems where (listStatus != null ? listStatus.Contains(item.StatusCode) : true) && (listMerchants != null ? listMerchants.Contains(item.MerchantId) : true) select item; Might give strange behavior if both listMerchants and listStatus are both null.
You can’t do that with a LINQ joins – LINQ only supports equijoins. However, you can do this: var query = from e in entity.M_Employee from p in entity.M_Position where e.PostionId >= p.PositionId select p; Or a slightly alternative but equivalent approach: var query = entity.M_Employee .SelectMany(e => entity.M_Position .Where(p => e.PostionId >= p.PositionId));
You aren’t deleting the object with the remove statement. Instead you are attempting to alter a record and make it an orphan (by setting the foreign key to null). The database has a non-null constraint on that column and prevents you from doing so.
You can use the Linq methods that are defined in the System::Linq namespace, but you’ll have to jump through a couple extra hoops. First, C++/CLI doesn’t support extension methods. However, the extension methods are regular methods defined on various classes in System::Linq, so you can call them directly. List<int>^ list = gcnew List<int>(); int i … Read more
If you need to do the Left joins then you have to use into and DefaultIfEmpty() as shown below. var result = from person in _dbContext.Person join detail in _dbContext.PersonDetails on person.Id equals detail.PersonId into Details from m in Details.DefaultIfEmpty() select new { id = person.Id, firstname = person.Firstname, lastname = person.Lastname, detailText = m.DetailText … Read more
Well, the easiest way would be to do it at the client side rather than the database side, and use the overload of Select which provides an index as well: public List<ScoreWithRank> GetHighScoresWithRank(string gameId, int count) { Guid guid = new Guid(gameId); using (PPGEntities entities = new PPGEntities()) { var query = from s in … Read more
While you cant expand them to columns, you can simply return the entities. Eg: select new { CTLJCRJOB, CTLRFDSTM } If you need it flattened, then you will have to write out the mapping yourself, but will still be very trivial.
There’s a difference between a null reference and an empty collection. It’s fine to call Take on an empty collection. And the argument specifies a maximum number to take, so it’s also fine to specify more than there are items in the collection. I recommend referring to MSDN for precise details like this. For Linq … Read more