ForeignKeyConstraint.UpdateRule Property
Definition
Important
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Gets or sets the action that occurs across this constraint on when a row is updated.
public:
virtual property System::Data::Rule UpdateRule { System::Data::Rule get(); void set(System::Data::Rule value); };
public virtual System.Data.Rule UpdateRule { get; set; }
[System.Data.DataSysDescription("ForeignKeyConstraintUpdateRuleDescr")]
public virtual System.Data.Rule UpdateRule { get; set; }
member this.UpdateRule : System.Data.Rule with get, set
[<System.Data.DataSysDescription("ForeignKeyConstraintUpdateRuleDescr")>]
member this.UpdateRule : System.Data.Rule with get, set
Public Overridable Property UpdateRule As Rule
Property Value
One of the Rule values. The default is Cascade
.
- Attributes
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
Applies to
See also
Met ons samenwerken op GitHub
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