How to set a default value on a Boolean in a Code First model?

Question

I have an existing table / model into which I want to drop a new Boolean column. This table already has many hundreds of rows of data, and I can\'t touch the existing data.

Answer 1

Another option is create a default constructor and set the properties with the default values you need:

public class Revision
{
    public Boolean IsReleased { get; set; }

    public Revision()
    {
        IsReleased=true;

    }
}

To set the values to true of the existing rows when you run Update-Database command, you could do this in your Configuration class:

protected override void Seed(YourContext context)
{
    var entities=context.Revisions.Where(r=>!r.IsReleased)
    foreach(var e in entities)
    {
      e.IsReleased=true;
     //context.Entry(e).State = EntityState.Modified; If you have disabled change tracking then add this line
    }
    context.SaveChanges();
}

Update

If it is a new column you are adding via migration maybe you can also do this:

AddColumn("dbo.Revisions", "IsReleased", c => c.Boolean(nullable: false, defaultValue: true));