Columns Property
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UniqueConstraint.Columns Property


Gets the array of columns that this constraint affects.

Namespace:   System.Data
Assembly:  System.Data (in System.Data.dll)

public virtual DataColumn[] Columns { get; }

Property Value

Type: System.Data.DataColumn[]

An array of DataColumn objects.

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)
    Next i
 End Sub

.NET Framework
Available since 1.1
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