UniqueConstraint.Columns Property

Definition

Namespace:

System.Data

Assembly:

System.Data.Common.dll

Source:

UniqueConstraint.cs

Gets the array of columns that this constraint affects.

public:
 virtual property cli::array <System::Data::DataColumn ^> ^ Columns { cli::array <System::Data::DataColumn ^> ^ get(); };

public virtual System.Data.DataColumn[] Columns { get; }

member this.Columns : System.Data.DataColumn[]

Public Overridable ReadOnly Property Columns As DataColumn()

Property Value

DataColumn[]

An array of DataColumn objects.

Examples

The following example returns the DataColumn objects that the UniqueConstraint constrains.

Private Sub GetColsFromConstraint()
    Dim dataColumns() As DataColumn

    ' Get a named relation from a DataSet.
    Dim dataRelation As DataRelation
    dataRelation = DataSet1.Relations("CustomerOrders")

    ' Get the ParentKeyConstraint
    Dim uniqueConstraint As UniqueConstraint
    uniqueConstraint= dataRelation.ParentKeyConstraint

    ' Get the DataColumn objects being constrained.
    dataColumns = uniqueConstraint.Columns

    ' Print the column name of each column.
    Dim i As Integer
    For i = 0 to dataColumns.GetUpperBound(0)
       Console.Write(dataColumns(i).ColumnName)
    Next i
 End Sub

See also

• Adding Constraints to a Table