You can write it using two from expressions like below: from a in Table1s from b in Table2s where a.ID1Table1 == b.ID1Table2 && a.ID2Table1 == b.ID2Table2 select new {a.ID1Table1, a.ID2Table1, a.Value1Table1, b.ID3Table2, b.Value1Table2} Using join: from a in Table1s join b in Table2s on new{PropertyName1 = a.ID1Table1, PropertyName2 = a.ID2Table1} equals new{PropertyName1 = b.ID1Table2, PropertyName2 … Read more
You may be changed the assembly name of the project that contained the model. The reference to the original assembly was still in the client application. ASP.net Web Application : – Manually delete dll and pdb files. ASP.net Web Site: – Perform an IIS reset then flush out the asp.net temporary files in the folder … Read more
The easiest way with DbContext and DbSet<T> is just to use ToString() on the IQueryable you have built. For example: var query = context.Blogs.Include(b => b.Posts) .Where(b => b.Title == “AnyTitle”); string sql = query.ToString(); sql contains the SQL command which will be issued to the DB when the query gets executed.
Sounds like your SQL date column is non-nullable, but you haven’t initialized the date on your entity before saving?
You can specify the type in Fluent API: modelBuilder.Entity<Book>() .Property(f => f.DateTimeAdded) .HasColumnType(“datetime2”); This creates a datetime2(7) column in the database. If you want to finetune the precision you can use: modelBuilder.Entity<Book>() .Property(f => f.DateTimeAdded) .HasColumnType(“datetime2”) .HasPrecision(0); … for a datetime2(0) column in the DB. However, the code you have shown in your question works … Read more
It took a lot of fiddling about and testing different things. I was clueless until I decided to make a new vanilla project with the similar data structure from scratch. And when I installed EntityFramework from NuGet, I was shown a message: Known Issues with Entity Framework 4.x and .NET Framework 4.5 Entity Framework 4.1 … Read more
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.
I faced this problem recently when I upgraded my Web Application from Entity Framework 5 to Entity Framework 6. Then, I realized that System.Data.Entity DLL needs to be removed from the application completely in order to work with Entity Framework 6. Entity Framework 6 is not part of .NET Framework anymore and therefore it is … Read more
for future reference: you can use data annotations MSDN EF – Code First Data Annotations [NotMapped] public string AddressAs { get; set; }
The interesting question here is your question from the comments: What kind of object would you have that you do not need to modify the values at some point? I’m guessing not a model class, correct? I’ve had to change the name of a person in my database – this wouldn’t fit with this idea. … Read more