ConstraintCollection.Add Method (String, DataColumn, DataColumn)

 

Constructs a new ForeignKeyConstraint with the specified name, parent column, and child column, and adds the constraint to the collection.

Namespace:   System.Data
Assembly:  System.Data (in System.Data.dll)

public Constraint Add(
	string name,
	DataColumn primaryKeyColumn,
	DataColumn foreignKeyColumn
)

Parameters

name
Type: System.String

The name of the ForeignKeyConstraint.

primaryKeyColumn
Type: System.Data.DataColumn

The primary key, or parent, DataColumn.

foreignKeyColumn
Type: System.Data.DataColumn

The foreign key, or child, DataColumn.

Return Value

Type: System.Data.Constraint

A new ForeignKeyConstraint.

The CollectionChanged event occurs if the constraint is added successfully.

The following example adds a new ForeignKeyConstraint to the ConstraintCollection of a DataTable.

private void AddForeignConstraint(DataSet dataSet)
{
    try
    {
        DataColumn parentColumn = 
            dataSet.Tables["Suppliers"].Columns["SupplierID"];
        DataColumn childColumn = 
            dataSet.Tables["Products"].Columns["SupplierID"];
        dataSet.Tables["Products"].Constraints.Add
            ("ProductsSuppliers", parentColumn, childColumn);
    }
    catch(Exception ex)
    {
        // In case the constraint already exists, 
        // catch the collision here and respond.
        Console.WriteLine("Exception of type {0} occurred.", 
            ex.GetType());
    }
}

.NET Framework
Available since 1.1
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