It’s possible. Here’s an extension method: public static bool IsOrdered<T>(this IQueryable<T> queryable) { if (queryable == null) { throw new ArgumentNullException(nameof(queryable)); } return queryable.Expression.Type == typeof(IOrderedQueryable<T>); }
I have been thinking about this a lot lately, after starting at my current job. I am used to Repositories, they go the full IQueryable path using just bare bones repositories as you suggest. I feel the repo pattern is sound and does a semi-effective job at describing how you want to work with the … Read more
OrderBy(i => i.PropertyName).ThenBy(i => i.AnotherProperty) In OrderBy and ThenBy you have to provide keySelector function, which chooses key for sorting from object. So if you know property name only at runtime then you can make such function with Reflection like: var propertyInfo = i.GetType().GetProperty(“PropertyName”); var sortedList = myList.OrderBy(i => propertyInfo.GetValue(i, null)) But it will be … Read more
You can’t have extension methods invoked on anonymous lambda expressions, so you’ll want to use a Cache class. In order to properly cache a query you’ll also need to ‘lift’ any parameters (including your DataContext) into parameters for your lambda expression. This results in very verbose usage like: var results = QueryCache.Cache((MyModelDataContext db) => from … Read more
it will return an iQueryable, you will need to do something like using the First cit.CountryID = db.Countries.First(a=>a.DOTWInternalID == citee.CountryCode).ID
Do you want to add it to the database, or just to the list of results that other things like databinding will use? If it’s the former, you’ll need to use the normal add operation for whatever kind of LINQ you’re using, but to the table representation rather than the IQueryable. Queries only read data. … Read more
It depends on what behavior you want. Returning an IList<T> tells the caller that they’ve received all of the data they’ve requested Returning an IEnumerable<T> tells the caller that they’ll need to iterate over the result and it might be lazily loaded. Returning an IQueryable<T> tells the caller that the result is backed by a … Read more
I usually do exactly what you ended up doing in your test. When writing my tests I assume that the .Net library classes work correctly and don’t contain bugs, so I can use them in the tests. When I need a test list, collection, queryable, dictionary, etc. I just create the real thing and populate … Read more
I get stuck on this issue today and this lib resolve it for me https://github.com/romantitov/MockQueryable completely, please refer: Mocking Entity Framework Core operations such ToListAsync, FirstOrDefaultAsync etc. //1 – create a List<T> with test items var users = new List<UserEntity>() { new UserEntity{LastName = “ExistLastName”, DateOfBirth = DateTime.Parse(“01/20/2012”)}, … }; //2 – build mock by … Read more
You’re not using the return value – just like all other LINQ operators, the method doesn’t change the existing sequence – it returns a new sequence. So try this: var list3 = list1.Concat(list2); or var list4 = list1.Union(list2); Union is a set operation – it returns distinct values. Concat simply returns the items from the … Read more