This abstract class represents a rule that can be placed on one or more DataColumn objects. ADO.NET includes two derived constraint classes: ForeignKeyConstraint and UniqueConstraint . Constraints aren't enforced unless the EnforceConstraints property of the DataSet is true.

public abstract class Constraint {
// Protected Constructors
   protected Constraint(  );
// Public Instance Properties
   public virtual string ConstraintName{set; get; } 
   public PropertyCollection ExtendedProperties{get; } 
   public abstract DataTable Table{get; }
// Protected Instance Properties
   protected internal virtual DataSet _DataSet{get; } 
// Public Instance Methods
   public override string ToString(  );                          // overrides object
// Protected Instance Methods
   protected void CheckStateForProperty(  );  
   protected internal void SetDataSet( DataSet dataSet);  
}

Subclasses

ForeignKeyConstraint , UniqueConstraint

Returned By

ConstraintCollection.{Add( ) , this}

Passed To

ConstraintCollection.{Add( ) , AddRange( ) , CanRemove( ) , IndexOf( ) , Remove( )}