That’s because you are using LINQ To Entities which is ultimately convert your Lambda expressions into SQL statements. That means the case sensitivity is at the mercy of your SQL Server which by default has SQL_Latin1_General_CP1_CI_AS Collation and that is NOT case sensitive. Using ObjectQuery.ToTraceString to see the generated SQL query that has been actually … Read more
If you remove the connection string from the app.config file, re-running the entity Data Model wizard will guide you to build a new connection.
Check to see if you have any ICollections. What I have figured out is when you have an ICollection that references a table and there is no column that it can figure out, it creates one for you to try to make the connection between the tables. This specifically happens with ICollection and has driven … Read more
I got annoyed by this recently too. I fixed it by putting a wrapper function in the Configuration class in the Seed method, and replaced calls to SaveChanges with calls to my function instead. This function would simply enumerate the errors within the EntityValidationErrors collection, and rethrow an exception where the Exception message lists the … Read more
Here is an overview of the different methods: Find() – when you want to get an item by primary key. This will return null if it can’t find an item. It will look in the context before going to the database (as pointed out by Yaron in the comments) which can be an important efficiency … Read more
ObjectContext.AddObject and ObjectSet.AddObject: The AddObject method is for adding newly created objects that do not exist in the database. The entity will get an automatically generated temporary EntityKey and its EntityState will be set to Added. When SaveChanges is called, it will be clear to the EF that this entity needs to be inserted into … Read more
In addition to connecting with a read-only user, there are a few other things you can do to your DbContext. public class MyReadOnlyContext : DbContext { // Use ReadOnlyConnectionString from App/Web.config public MyContext() : base(“Name=ReadOnlyConnectionString”) { } // Don’t expose Add(), Remove(), etc. public DbQuery<Customer> Customers { get { // Don’t track changes to query … Read more
DateTime.Date cannot be converted to SQL. Use EntityFunctions.TruncateTime method to get date part. var eventsCustom = eventCustomRepository .FindAllEventsCustomByUniqueStudentReference(userDevice.UniqueStudentReference) .Where(x => EntityFunctions.TruncateTime(x.DateTimeStart) == currentDate.Date); UPDATE: As @shankbond mentioned in comments, in Entity Framework 6 EntityFunctions is obsolete, and you should use DbFunctions class, which is shipped with Entity Framework.
I think it will be easier using syntax-based query: var entryPoint = (from ep in dbContext.tbl_EntryPoint join e in dbContext.tbl_Entry on ep.EID equals e.EID join t in dbContext.tbl_Title on e.TID equals t.TID where e.OwnerID == user.UID select new { UID = e.OwnerID, TID = e.TID, Title = t.Title, EID = e.EID }).Take(10); And you should … Read more
I suspect that your issue is coming from the fact that you have more than one project in your solution and the one that contains your entity framework stuff including edmx files is NOT the solutions’s startup project. In this case even if the connection string exists in the EF app.config project, still CLR cannot … Read more