Check for null entities in EF statement

Using HTML, create an empty textbox. An EF entity's TextBoxFor on a not-null attribute

I am using Entity Framework (v4) entities. I have an entity called Car with a Year property of type integer. The Year property does not allow NULL. I have the following in my Create view:...<%= Html.TextBoxFor(model => model.Year) %> ...I am required to return a new Car object (due to other requirements) in my HttpGet Create action in the CarContro...

LINQ and Entity Framework are used to check for null values in C# variables.

In VB...Dim entry = myDB.Entries.Where(Function(e) e.Email = entry.Email).SingleOrDefault()...If entry IsNot Nothing Then...' we have a value...else...' we dont have a value...End If

In Entity Framework, check for null values in Linq queries.

If you are comparing to a ...null... value, you must first compare your value to ...null... due to a bug....var field = from field in table where (value == null ? field.property == null : field.property == value) select field;

Is Null, Is Not Null in Entity Framework Linq

From what I can tell, the problem look like the condition of the query are not written correctly. Let check what will append with an example:...The Data:...Id = 1, Param1 = null, Param2 = null Id = 2, Param1 = 'a' param2 = null Id = 3, Param1 = null, Param2 = 'b' Id = 4, Param1 = 'a' param2 = 'c' ...With the current query and the other solution...

LINQ check if FirstOrDefault is null and use it

My take:...int count = itemsQuery.Select(i => i.Assignments.OrderByDescending(a => a.DateAssigned)) .Count(i => i.FirstOrDefault() != null && i.First().DateReturned == null);

CREATE DATABASE statement not allowed within multi-statement transaction

You can also use ...db.Database.ExecuteSqlCommand(TransactionalBehavior.DoNotEnsureTransaction, sqlCommand);...See ...https://stackoverflow.com/a/24344654/375114... for details

EF (entity framework) usage of "using" statement

The proper or best practice way of using DBContext variable is with the Using. ... using (var db = new MyEntities()) { return db.Items.Where(it => it.ItemId == itemId && !it.IsDeleted).FirstOrDefault(); } ...The benefit is many things are done automatically for us. For example once the block of code is completed the dispose is ca...

How to check model string property for null in a razor view

I am working on an ...ASP.NET MVC 4... application. I use ...EF 5... with code first and in one of my entities I have :...public string ImageName { get; set; } public string ImageGUIDName { get; set; } ...those two properties which are part of my entity. Since I may not have image uploaded these values can be null but when I render the view passing...

Check if EF entity already exist in current context

This worked for me:...public virtual async Task<bool> InsertOrUpdate(TE entity) { if (entity.Id == 0 || entity.Id == ModelState.New) { // insert new item _context.Entry<TE>(entity).State = EntityState.Added; } else { var attachedEntity = _context.ChangeTracker.Entries<TE>().FirstOrDefault(e => ...

FirstOrDefault inline null checking

You can use ...Enumerable.DefaultIfEmpty Method...Rating = s.Performance.OrderByDescending(o => o.Year) .Select(o => o.Rating) .DefaultIfEmpty(0) .First()