ConstraintCollection.Add Method (Constraint)

 

Adds the specified Constraint object to the collection.

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

public void Add(
	Constraint constraint
)

Parameters

constraint
Type: System.Data.Constraint

The Constraint to add.

Exception Condition
ArgumentNullException

The constraint argument is null.

ArgumentException

The constraint already belongs to this collection, or belongs to another collection.

DuplicateNameException

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

If the collection is successfully changed by adding or removing constraints, the CollectionChanged event occurs.

The following example adds a UniqueConstraint to the ConstraintCollection of a DataTable.

private void AddConstraint(DataTable table)
{
    UniqueConstraint uniqueConstraint;
    // Assuming a column named "UniqueColumn" exists, and 
    // its Unique property is true.
    uniqueConstraint = new UniqueConstraint(
        table.Columns["UniqueColumn"]);
    table.Constraints.Add(uniqueConstraint);
}

.NET Framework
Available since 1.1
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