Question

I have a table with the following:

CREATE TABLE [Location]([ADDRESS1] [nvarchar](50) NOT NULL DEFAULT (' '));

I import it into Entity Framework 4.1.

Entity Framework’s designer shows this:

[EdmScalarPropertyAttribute(EntityKeyProperty=false, IsNullable=false)]
        [DataMemberAttribute()]
        public global::System.String ADDRESS1
        {
            get
            {
                return _ADDRESS1;
            }
            set
            {
                OnADDRESS1Changing(value);
                ReportPropertyChanging("ADDRESS1");
                _ADDRESS1 = StructuralObject.SetValidValue(value, false);
                ReportPropertyChanged("ADDRESS1");
                OnADDRESS1Changed();
            }
        }
        private global::System.String _ADDRESS1 = " ";
        partial void OnADDRESS1Changing(global::System.String value);
        partial void OnADDRESS1Changed();

When I build it, I get a *.web.g.cs file in my Silverlight application and the field looks like this:

 [DataMember()]
        [Required()]
        [StringLength(50)]
        public string ADDRESS1
        {
            get
            {
                return this._address1;
            }
            set
            {
                if ((this._address1 != value))
                {
                    this.OnADDRESS1Changing(value);
                    this.RaiseDataMemberChanging("ADDRESS1");
                    this.ValidateProperty("ADDRESS1", value);
                    this._address1 = value;
                    this.RaiseDataMemberChanged("ADDRESS1");
                    this.OnADDRESS1Changed();
                }
            }
        }

Am I missing a setting in Entity Framework? It appears to me that if the field is NOT NULL code generation is flagging the field as required, even though I am telling it the default is string.empty (or blank).

Answer 1

NOT NULL means required. That’s the only thing that controls where a value must be supplied.

An empty string for new records does not mean you can’t explicitly insert a NULL value, but NOT NULL will stop you doing that.