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ForeignKeyConstraint Constructor (String, DataColumn[], DataColumn[])

Initializes a new instance of the ForeignKeyConstraint class with the specified name, and arrays of parent and child DataColumn objects.

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

public ForeignKeyConstraint(
	string constraintName,
	DataColumn[] parentColumns,
	DataColumn[] childColumns


Type: System.String
The name of the ForeignKeyConstraint. If null or empty string, a default name will be given when added to the constraints collection.
Type: System.Data.DataColumn[]
An array of parent DataColumn in the constraint.
Type: System.Data.DataColumn[]
An array of child DataColumn in the constraint.


One or both of the columns is null.


The columns have different data types.

-Or -

The tables don't belong to the same DataSet.

The following example creates a new ForeignKeyConstraint, sets some of its properties, and adds it to a DataTable object's ConstraintCollection.

Private Sub CreateConstraint(ByVal suppliersProducts As DataSet)
    ' Declare parent column and child column variables.
    Dim parentColumns(1) As DataColumn
    Dim childColumns(1) As DataColumn
    Dim fkConstraint As ForeignKeyConstraint

    ' Set parent and child column variables.
    parentColumns(0) = _
    parentColumns(1) = _
    childColumns(0) = _
    childColumns(1) = _
    fkConstraint = New ForeignKeyConstraint( _
        "ProductSalesOrders", parentColumns, childColumns)

    ' Set various properties of the constraint.
    With fkConstraint
        .DeleteRule = Rule.SetDefault
        .UpdateRule = Rule.Cascade
        .AcceptRejectRule = AcceptRejectRule.Cascade
    End With

    ' Add the constraint, and set EnforceConstraints to true.
    suppliersProducts.Tables("OrderDetails").Constraints.Add( _
    suppliersProducts.EnforceConstraints = True
End Sub

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.