ColumnAttribute.CanBeNull Property

Reference

Definition

Namespace:: System.Data.Linq.Mapping

Assembly:: System.Data.Linq.dll

Important

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Gets or sets whether a column can contain null values.

public:
 property bool CanBeNull { bool get(); void set(bool value); };

public bool CanBeNull { get; set; }

member this.CanBeNull : bool with get, set

Public Property CanBeNull As Boolean

Property Value

Boolean

Default = true.

Examples

[Column(Storage="_LastName", DbType="NVarChar(20) NOT NULL", CanBeNull=false)]
public string LastName
{
    get
    {
        return this._LastName;
    }
    set
    {
        if ((this._LastName != value))
        {
            this.OnLastNameChanging(value);
            this.SendPropertyChanging();
            this._LastName = value;
            this.SendPropertyChanged("LastName");
            this.OnLastNameChanged();
        }
    }
}

<Column(Storage:="_LastName", DbType:="NVarChar(20) NOT NULL", CanBeNull:=false)>  _
Public Property LastName() As String
    Get
        Return Me._LastName
    End Get
    Set
        If ((Me._LastName = value)  _
                    = false) Then
            Me.OnLastNameChanging(value)
            Me.SendPropertyChanging
            Me._LastName = value
            Me.SendPropertyChanged("LastName")
            Me.OnLastNameChanged
        End If
    End Set
End Property

Remarks

If you set this value to false, the data in the corresponding column is assumed to be non-null.

Napomena

This property is duplicated from the DbType property for convenience. The CreateDatabase method uses only the DbType property. For this reason, you must specify whether a column can contain null values in the DbType property also.

Applies to

Proizvod	Verzije
.NET Framework	3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1

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