DataColumn.AllowDBNull Property

Definition

Namespace:
System.Data
Assembly:
System.Data.Common.dll
Assembly:
System.Data.dll
Assembly:
netstandard.dll

Gets or sets a value that indicates whether null values are allowed in this column for rows that belong to the table.

public:
 property bool AllowDBNull { bool get(); void set(bool value); };
public bool AllowDBNull { get; set; }
[System.Data.DataSysDescription("DataColumnAllowNullDescr")]
public bool AllowDBNull { get; set; }
member this.AllowDBNull : bool with get, set
[<System.Data.DataSysDescription("DataColumnAllowNullDescr")>]
member this.AllowDBNull : bool with get, set
Public Property AllowDBNull As Boolean

Property Value

Boolean

true if null values are allowed; otherwise, false. The default is true.

Attributes
DataSysDescriptionAttribute

Examples

The following example creates a new DataColumn and sets its AllowDBNull property to true.

private void AddNullAllowedColumn()
{
    DataColumn column;
    column = new DataColumn("classID",
        System.Type.GetType("System.Int32"));
    column.AllowDBNull = true;

    // Add the column to a new DataTable.
    DataTable table;
    table = new DataTable();
    table.Columns.Add(column);
}

Private Sub AddNullAllowedColumn()
    Dim column As DataColumn
    column = New DataColumn("classID", _
        System.Type.GetType("System.Int32"))
    column.AllowDBNull = True

    ' Add the column to a new DataTable.
    Dim table As DataTable
    table = New DataTable
    table.Columns.Add(column)
End Sub

Applies to

See also