ForeignKeyConstraint.UpdateRule
Property
Definition
Gets or sets the action that occurs across this constraint on when a row is updated.
public virtual System.Data.Rule UpdateRule { get; set; }
Property Value
Examples
The following example creates a ForeignKeyConstraint, sets various of its properties, and adds it to a DataTable object's ConstraintCollection.
' The next line goes into the Declarations section of the module:
' SuppliersProducts is a class derived from DataSet.
Private suppliersProducts As SuppliersProducts
Private Sub CreateConstraint()
' Declare parent column and child column variables.
Dim parentColumn As DataColumn
Dim childColumn As DataColumn
Dim fkConstraint As ForeignKeyConstraint
' Set parent and child column variables.
parentColumn = suppliersProducts.Tables("Suppliers").Columns("SupplierID")
childColumn = suppliersProducts.Tables("Products").Columns("SupplieriD")
fkConstraint = New ForeignKeyConstraint( _
"SuppierFKConstraint", parentColumn, childColumn)
' Set null values when a value is deleted.
fkConstraint.DeleteRule = Rule.SetNull
fkConstraint.UpdateRule = Rule.Cascade
fkConstraint.AcceptRejectRule = AcceptRejectRule.Cascade
' Add the constraint, and set EnforceConstraints to true.
suppliersProducts.Tables("Suppliers").Constraints.Add(fkConstraint)
suppliersProducts.EnforceConstraints = True
End Sub