Calculated column in EF Code First

Question

I need to have one column in my database calculated by database as (sum of rows) - (sum of rowsb). I\'m using code-first model to create my database.

Here is what I

Answer 1

As of 2019, EF core allows you to have computed columns in a clean way with the fluent API:

Suppose that DisplayName is the computed column you want to define, you have to define the property as usual, possibly with a private property accessor to prevent assigning it

public class Person
{
    public int PersonId { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    // this will be computed
    public string DisplayName { get; private set; }
}

Then, in the model builder, address it with the column definition:

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Entity()
        .Property(p => p.DisplayName)
        // here is the computed query definition
        .HasComputedColumnSql("[LastName] + ', ' + [FirstName]");
}

For further information, have a look at MSDN.