DataColumn.AllowDBNull Property
Important
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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); };C#
public bool AllowDBNull { get; set; }C#
[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, setPublic Property AllowDBNull As Booleantrue if null values are allowed; otherwise, false. The default is true.
- Attributes
The following example creates a new DataColumn and sets its AllowDBNull property to true.
C#
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
| Produkt | Versiounen |
|---|---|
| .NET | Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10 |
| .NET Framework | 1.1, 2.0, 3.0, 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 |
| .NET Standard | 2.0, 2.1 |
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