ForeignKeyConstraint Constructor (String^, DataColumn^, DataColumn^)
.NET Framework (current version)
Initializes a new instance of the ForeignKeyConstraint class with the specified name, parent and child DataColumn objects.
Assembly: System.Data (in System.Data.dll)
public:
ForeignKeyConstraint(
String^ constraintName,
DataColumn^ parentColumn,
DataColumn^ childColumn
)
Parameters
- constraintName
-
Type:
System::String^
The name of the constraint.
- parentColumn
-
Type:
System.Data::DataColumn^
The parent DataColumn in the constraint.
- childColumn
-
Type:
System.Data::DataColumn^
The child DataColumn in the constraint.
| Exception | Condition |
|---|---|
| ArgumentNullException | One or both of the columns is null. |
| InvalidConstraintException |
The following example creates a new ForeignKeyConstraint, sets some 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 fkeyConstraint As ForeignKeyConstraint ' Set parent and child column variables. parentColumn = _ suppliersProducts.Tables("Suppliers").Columns("SupplierID") childColumn = _ suppliersProducts.Tables("Products").Columns("SupplierID") fkeyConstraint = New ForeignKeyConstraint( _ "SupplierFKConstraint", parentColumn, childColumn) ' Set various properties of the constraint. With fkeyConstraint .DeleteRule = Rule.SetNull .UpdateRule = Rule.Cascade .AcceptRejectRule = AcceptRejectRule.Cascade End With ' Add the constraint, and set EnforceConstraints to true. suppliersProducts.Tables("Products").Constraints.Add(fkeyConstraint) suppliersProducts.EnforceConstraints = True End Sub
.NET Framework
Available since 1.1
Available since 1.1
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