Autogenerate primary key (Guid) Entity Framework CTP5

问题

I have a following POCO class

public class Account
    {
        [Key,DatabaseGenerated(DatabaseGenerationOption.Identity)]
        public string AccountId { set; get; }

        public string FirstName { set; get; }

        public string LastName { set; get; }

        public string Email { set; get; }


    }

I get the following exception when the database gets created

Identity column 'AccountId' must be of data type int, bigint, smallint, tinyint, or decimal or numeric with a scale of 0, and constrained to be nonnullable.

回答1:

Shouldn't you have:

    [Key,DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid AccountId { set; get; }

?

回答2:

Jeff's answer is right. Just a little tip for you. Using EF6 I wrote next configuration in order to set all fields with name "Id" and type "Guid" as identity.

modelBuilder.Properties<Guid>()
           .Where(info => info.Name.ToLower()== "id")
           .Configure(configuration => configuration.HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity));

So I don't have to write [DatabaseGenerated(DatabaseGenerationOption.Identity)] everytime.

回答3:

Sound like you have to update your AccountId property from string to one of the mentioned datatypes in the exception:

int, bigint, smallint, tinyint, or decimal or numeric with a scale of 0, and constrained to be nonnullable

Any reason why it's now a string?

来源：https://stackoverflow.com/questions/5610794/autogenerate-primary-key-guid-entity-framework-ctp5