EF Core Many-to-Many Relation Table Naming [duplicate] - entity-framework

Question

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Change name of generated Join table ( Many to Many ) - EF Core 5
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Does EF Core provide a way of naming the many-to-many relations mapping to database tables ?
In a code-first pattern, I have the following 2 Entities:
[Table("Prefix.Users")]
public class User
{
public int ID { get; set; }
public IEnumerable<Role> Roles { get; set; }
}
[Table("Prefix.Roles")]
public class Role
{
public int ID { get; set; }
public IEnumerable<User> Users { get; set; }
}
I've skipped the detailed Entity structure here. The ID properties in User & Role are keys (Database generated Identity)
User and Role entities share a many-to-many relationship.
EF Core generates a third table in Database with Table name UsersRoles
Is there a way I can add a prefix to the 3rd table name so it becomes Prefix.UsersRoles without manually adding a third Entity UserRoles that maps User and Role and giving it the desired name with Prefix

Answer 1

Use fluent API instead of using data annotations
Your model classes should be like this.
public class User
{
public int Id { get; set; }
public string Username { get; set; }
public string Email { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public string Password { get; set; }
public virtual ICollection<UserRole> UserRoles { get; set; }
}
public class Role
{
public int Id { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public virtual ICollection<UserRole> UserRoles { get; set; }
}
public class UserRole
{
public int UserId { get; set; }
public int RoleId { get; set; }
public virtual User User { get; set; }
public virtual Role Role { get; set; }
}
Your fluent api configuration classes like be this
public class UserConfiguration : IEntityTypeConfiguration<User>
{
public void Configure(EntityTypeBuilder<User> builder)
{
builder.ToTable("User");
builder.HasKey(x => x.Id);
}
}
public class RoleConfiguration : IEntityTypeConfiguration<Role>
{
public void Configure(EntityTypeBuilder<Role> builder)
{
builder.ToTable("Role");
builder.HasKey(x => x.Id);
}
}
public class UserRoleConfiguration : IEntityTypeConfiguration<UserRole>
{
public void Configure(EntityTypeBuilder<UserRole> builder)
{
builder.ToTable("UserRole");
builder.HasKey(x => new { x.UserId, x.RoleId });
builder
.HasOne<Role>(s => s.Role)
.WithMany(r => r.UserRoles)
.HasForeignKey(s => s.RoleId).OnDelete(DeleteBehavior.Restrict);
builder
.HasOne<User>(s => s.User)
.WithMany(r => r.UserRoles)
.HasForeignKey(s => s.UserId).OnDelete(DeleteBehavior.Restrict);
}
}
Your DbContext class should be like this
public class MyDbContext : DbContext
{
public EEGDbContext()
{
}
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
if (!optionsBuilder.IsConfigured)
{
optionsBuilder.UseSqlServer(#"Server=xxxx;Database=DB;User Id=sa;Password=xxxxx;");
}
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.ApplyConfiguration(new UserConfiguration());
modelBuilder.ApplyConfiguration(new RoleConfiguration());
modelBuilder.ApplyConfiguration(new UserRoleConfiguration());
base.OnModelCreating(modelBuilder);
}
public DbSet<User> Users { get; set; }
public DbSet<Role> Roles { get; set; }
public DbSet<UserRole> UserRoles { get; set; }
}