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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)

'Declaration
Public Sub New ( _
	constraintName As String, _
	parentColumns As DataColumn(), _
	childColumns As DataColumn() _
)

Parameters

constraintName
Type: System.String

The name of the ForeignKeyConstraint. If Nothing or empty string, a default name will be given when added to the constraints collection.

parentColumns
Type: System.Data.DataColumn()

An array of parent DataColumn in the constraint.

childColumns
Type: System.Data.DataColumn()

An array of child DataColumn in the constraint.

ExceptionCondition
ArgumentNullException

One or both of the columns is Nothing.

InvalidConstraintException

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) = _
        suppliersProducts.Tables("OrderDetails").Columns("OrderID")
    parentColumns(1) = _
        suppliersProducts.Tables("OrderDetails").Columns("ProductID")
    childColumns(0) = _
        suppliersProducts.Tables("Sales").Columns("OrderID")
    childColumns(1) = _
        suppliersProducts.Tables("Sales").Columns("ProductID")
    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( _
        fkConstraint)
    suppliersProducts.EnforceConstraints = True 
End Sub

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0
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