Create custom property mapping for all properties in EF6

Question

Model:

Entity class as the Id is shared between all entities

public abstract class Entity
{
    public int Id { get; set; }
}

And the Student class, which inherits the Entity class

public class Student : Entity
{
    public string LastName { get; set; }

    public string Forenames { get; set; }

    public DateTime EnrolmentDate { get; set; }

    public virtual ICollection<Enrolment> Enrolments { get; set; }
}

Table columns have the naming convention STUDENT_ID, LAST_NAME, FORENAMES etc. All tables will have the ID column of [NAME]_ID

How do I create a custom mapping for all properties in all entity classes? The code referenced here does not work as the .Entities() method does not exist any more.

score 2 · Answer 1 · answered Nov 28 '15 at 12:07

Override the OnModelCreating method on the context class, and then you can set a custom name for the ID column for each entity like this:

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    modelBuilder.Entity<Student>().Property(x => x.Id).HasColumnName("STUDENT_ID");
    modelBuilder.Entity<Teacher>().Property(x => x.Id).HasColumnName("TEACHER_ID");
}

score 1 · Answer 2 · answered Nov 28 '15 at 11:50

1

You can use the column attribute to have the custom column name mapping:

public class Student
{
  [Column("STUDENT_ID")]
  public int Id { get; set; }

  //...
}

answered Nov 28 '15 at 11:50

PythaLye

314
1
8

I'll try this. However, all my entity classes will eventually inherit from a custom class Entity as the ID column will be shared between all entities. Is there a way to set a column as [Entity]_ID? – Omar.Ebrahim Nov 28 '15 at 11:54

score 1 · Accepted Answer · edited May 23 '17 at 10:30

I am unable to mark both answers as correct (which they are), but the idea I was trying to get to was to set all column names automatically map from ColumnName to COLUMN_NAME without having to specify the column name manually for every property.

I found the answer from Loop over entity column mappings to transform column name which works for every column except the ID column, so I just set these manually with the code that Yacoub Massad suggested.

So:

// Make all properties UPPER_CASE
modelBuilder.Properties()
            .Configure(x => x.HasColumnName(Regex.Replace(x.ClrPropertyInfo.Name, "(?<=.)(?=[A-Z])", "_").ToUpper()));

// Set the ID columns to ENTITY_ID
modelBuilder.Entity<Course>()
    .ToTable("COURSE")
    .Property(x => x.Id)
    .HasColumnName("STUDENT_ID");

Setting the [Column("ENTITY_ID")] attribute for every property would be fine if I didn't have that many tables and columns, but as the database grows and there are more and more entity classes added it can be quite repetitive and could be brittle as it's manually named.

Create custom property mapping for all properties in EF6

3 Answers3