With EF Code-First it’s easy create a database starting from domain objects,
but it’s always possible create an our custom configuration.
In my project I have two class, Role and User:
public class Role
{
public Guid Id { get; set; }
public string Name { get; set; }
}
public class User
{
IList<Role> _role;
public virtual IList<Role> Roles
{
get { return _role ?? ( _role = new List<Role>() ); }
}
public Guid Id { get; set; }
public string UserName{ get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
}
If you want create custom configuration for User and Role, you can write others two class that works as configuration, RoleConfigration and UserConfiguration that extend EntityTypeConfiguration:
// custom configuration for Role
public class RoleConfiguration : EntityTypeConfiguration<Role>
{
public RoleMapping()
{
ToTable( "Roles" ); // ef will create a table with name Roles
HasKey(o => o.Id); // define a key
Property( o => o.Name ).IsRequired(); // this property is required on repository
}
}
// custom configuration for User
public class UserConfiguration : EntityTypeConfiguration<User>
{
public UserMapping()
{
ToTable( "Users" ); // ef will create a table with name Users
HasKey(o => o.Id); // define a key
// the property is required on repository
Property( o => o.UserName ).IsRequired();
// this property is nullable and map on column with name firstname
Property( o => o.FirstName ).HasColumnName("firstname");
// this property is nullable and map on column with name lastname
Property( o => o.LastName ).HasColumnName("lastname");
// configure many-to-many navigation property between
// User and Role
HasMany( o => o.Roles ).WithMany();
}
}
Now, for use our custom configuration, we will simply add RoleConfiguration and UserConfiguration to DbContext:
public class MyDbContext : DbContext
{
public virtual IDbSet CreateSet()
where TEntity : class
{
return Set();
}
protected override void OnModelCreating( DbModelBuilder modelBuilder )
{
modelBuilder.Configurations.Add( new RoleConfiguration() );
modelBuilder.Configurations.Add( new UserConfiguration() );
base.OnModelCreating( modelBuilder );
}
}
Hope this helps,
Tony
.
