C# – ‘Date’ is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported

centity-frameworklinqlinq-to-entities

I am trying to execute the following code and am receiving an error

public List<Log> GetLoggingData(DateTime LogDate, string title)
{
     var context = new LoggingEntities();
     var query = from t in context.Logs

           where t.Title == title 
           && t.Timestamp == LogDate

           select t;
     return query.ToList();
}

The error I'm receiving is "The specified type member 'Date' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported." I have tried various attempts of casting everythign to a string, only comparing the date part, but can't seem to get the right combinaation. Any help is greatly appreciated.

Best Answer

If you are using EF 6.0+, you can use DbFunctions.TruncateTime(DateTime?) :

var query =
    from t in context.Logs
    where t.Title == title 
    && DbFunctions.TruncateTime(t.Timestamp) == LogDate.Date
    select t;

Note: For earlier version of EF where DbFunctions isn't available, EntityFunctions.TruncateTime(DateTime?) can be used instead.

Related Solutions

C# – LINQ to Entities group-by failure using .date

Use the EntityFunctions.TruncateTime method:

var myQuery = from p in dbContext.Trends
          group p by EntityFunctions.TruncateTime(p.UpdateDateTime) into g
          select new { k = g.Key, ud = g.Max(p => p.Amount) };

Entity-framework – Only initializers, entity members, and entity navigation properties are supported

Entity is trying to convert your Paid property to SQL and can't because it's not part of the table schema.

What you can do is let Entity query the table with no Paid filter and then filter out the not Paid ones.

public ActionResult Index()
{
    var debts = storeDB.Orders
        //.Where(o => o.Paid == false)
        .OrderByDescending(o => o.DateCreated);

    debts = debts.Where(o => o.Paid == false);

    return View(debts);
}

That, of course, would mean that you bringing all of the data back to the web server and filtering the data on it. If you want to filter on the DB server, you can create a Calculated Column on the table or use a Stored Procedure.

Best Answer

Related Solutions

C# – LINQ to Entities group-by failure using .date

Entity-framework – Only initializers, entity members, and entity navigation properties are supported

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