System.Data Namespace   ConstraintCollection Class

Constructs a new UniqueConstraint using the specified array of DataColumn objects, and adds it to the collection.

[ VB ]
Overridable Overloads Public Function Add ( _
   ByVal name As String, _
   ByVal columns( ) As DataColumn, _
   ByVal primaryKey As Boolean _
) As Constraint

[ C# ]
public virtual Constraint Add (
   String name,
   DataColumn [ ] columns,
   bool primaryKey
);

[ C++ ]
public: virtual Constraint* Add (
   String* name,
   DataColumn* columns [ ],
   bool primaryKey
);

[ JScript ]
public function Add (
   name : String,
   columns : DataColumn [ ],
   primaryKey : Boolean
) : Constraint

name

The name of the UniqueConstraint.

columns

An array of DataColumn objects that are affected by the constraint.

primaryKey

Indicates whether the columns are primary key columns. true if the columns are primary key columns; otherwise, false.

The CollectionChanged event occurs if the constraint is added succesfully.

The following example creates an array of DataColumn objects that are used to create a new UniqueConstraint in a given DataTable.

private void AddUniqueConstraint ( DataTable myTable ) {
   DataColumn [ ] myColumns = new DataColumn [1];
   myColumns [0] = myTable.Columns ["ID"];
   myColumns [1] = myTable.Columns ["Name"];
   myTable.Constraints.Add ( "idNameConstraint", myColumns, true );
}

Private Sub AddUniqueConstraint ( myTable As DataTable )
   Dim myColumns ( 1 ) As DataColumn
   myColumns ( 0 ) = myTable.Columns ( "ID" )
   myColumns ( 1 ) = myTable.Columns ( "Name" )
   myTable.Constraints.Add ( "idNameConstraint", myColumns, True )
End Sub

ConstraintCollection Members   ConstraintCollection.Add Overload List   UniqueConstraint