在Code First EF中将N重命名为N表

Question

I have two tables that are connect N to N:

[Table("Backoffice_Roles")]
public class Role
{
    [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid RoleId { get; set; }

    public ICollection<User> Users { get; set; }
}


[Table("Backoffice_Users")]
public class User
{
    // Primary key
    [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public Guid UserId { get; set; }

    public ICollection<Role> Roles { get; set; }
}

This all works fine and it creates 3 tables: Backoffice_Roles , Backoffice_Users and RoleUsers .

Is there a way to rename RoleUsers to Backoffice_RoleUsers ?

I tried renaming the table manually in the migration file but it gives this error:

System.Data.Entity.Infrastructure.DbUpdateException: An error occurred while saving entities that do not expose foreign key properties for their relationships. The EntityEntries property will return null because a single entity cannot be identified as the source of the exception. Handling of exceptions while saving can be made easier by exposing foreign key properties in your entity types. See the InnerException for details. ---> System.Data.Entity.Core.UpdateException: An error occurred while updating the entries. See the inner exception for details. ---> System.Data.SqlClient.SqlException: Invalid object name 'dbo.RoleUsers'.

This the migration without changing the name of the last table manually:

public override void Up()
{
    CreateTable(
        "dbo.Backoffice_Users",
        c => new
            {
                UserId = c.Guid(nullable: false, identity: true),
            })
        .PrimaryKey(t => t.UserId);

    CreateTable(
        "dbo.Backoffice_Roles",
        c => new
            {
                RoleId = c.Guid(nullable: false, identity: true),
            })
        .PrimaryKey(t => t.RoleId);

    CreateTable(
        "dbo.RoleUsers",
        c => new
            {
                Role_RoleId = c.Guid(nullable: false),
                User_UserId = c.Guid(nullable: false),
            })
        .PrimaryKey(t => new { t.Role_RoleId, t.User_UserId })
        .ForeignKey("dbo.Backoffice_Roles", t => t.Role_RoleId)
        .ForeignKey("dbo.Backoffice_Users", t => t.User_UserId)
        .Index(t => t.Role_RoleId)
        .Index(t => t.User_UserId);

}

Answer 1

Use following mapping to provide name for junction table:

modelBuilder.Entity<Role>()
            .HasMany(r => r.Users)
            .WithMany(u => u.Roles)
            .Map(m => m.ToTable("Backoffice_RoleUsers"));

You can provide mappings by overriding OnModelCreating method of your DbContext class.