Enum - saving to property / field

Question

Premise:
An enum in a model does not create a property / field to hold the enum value.

Question:
How do you have this enum value saves into a property / field?

What does declaring an enum value accomplish if it is not creating a corresponding property / field that saves the value?

        public enum Option : byte
        { Option1, Option2, Both};

Answer 1

An enum is a named constant. Enums are used like any constant.

OptionTest option = new OptionTest();
option.Value = Option.Option1;

public enum Option : byte
{ 
    Option1, 
    Option2,
    Both 
};

public class OptionTest
{
    public Option Value { get; set; }
}

Your expectation is not clear but if you are trying to figure out how to enums with Entity Framework then see if the following helps.

Value Conversions

Answer 2

enum are value types, based on a numeric with a defined set of values. once you define a enum type, you just use the type name. they can be cast as their base type (byte in your case) for your example Option:

public class MyClass
{
     private Option _optionPrivate = Option.Option1;
     public Option OptionField  = Option.Option1;
     public Option OptionProperty {get; set;} = Option.Option1
}

these all define a byte enum typed as Option

Answer 3

Hi @Dean Everhart

By default, for the Enum property, EF core will create the column with int type:

For example:

Using the following class, after generating the table via EF core migration, the customer table will generate a MembershipType column with int type. When insert new customer, the MembershipType column value is: 0, 1, 2 ...

    public class Customer
    {
        [Key]
        public int Id { get; set; }

        public string FirstName { get; set; }

        public string LastName { get; set; }

        public MembershipType MembershipType { get; set; }
    }
    public enum MembershipType
    {
        Free,
        Premium,
        SuperVIP
    }

The result:

If change the enum as below:

    public enum MembershipType:byte
    {
        Free,
        Premium,
        SuperVIP
    }

After migration, the MembershipType column is tinyint type: When insert new customer, the MembershipType column value is: 0, 1, 2...

If you want to save the enum value as string format. You can add the value conversion in the OnModelCreating method, like this:

        public DbSet<Customer> Customers { get; set; } 
        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);
            modelBuilder.Entity<Customer>()
            .Property(u => u.MembershipType)
            .HasConversion<string>()
            .HasMaxLength(50);
        }

The result as below: and when add customer, the MembershipType column value is: Free, Premium and SuperVIP.

Besides, you can also refer this screenshot:

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Best regards,

Dillion