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DataRelationCollection.Add Method (String, DataColumn[], DataColumn[])

Creates a DataRelation with the specified name and arrays of parent and child columns, and adds it to the collection.

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

public virtual DataRelation Add (
	string name,
	DataColumn[] parentColumns,
	DataColumn[] childColumns
public DataRelation Add (
	String name, 
	DataColumn[] parentColumns, 
	DataColumn[] childColumns
public function Add (
	name : String, 
	parentColumns : DataColumn[], 
	childColumns : DataColumn[]
) : DataRelation



The name of the DataRelation to create.


An array of parent DataColumn objects.


An array of child DataColumn objects.

Return Value

The created DataRelation.

Exception typeCondition


The relation name is a null value.


The relation already belongs to this collection, or it belongs to another collection.


The collection already has a relation with the same name. (The comparison is not case sensitive.)


The relation has entered an invalid state since it was created.

If the relation is successfully added to the collection, the CollectionChanged event occurs.

When a DataRelation object is added to the collection, ForeignKeyConstraint and UniqueConstraint objects are created by default if they do not already exist.

private void AddRelation() 
    DataTable table = new DataTable();
    DataColumn column1 = table.Columns.Add("Column1");
    DataColumn column2 = table.Columns.Add("Column2");
    table.ChildRelations.Add("New Relation", column1, column2);

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0