NGWS SDK Documentation  

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DataRelation Constructor (String, DataColumn[], DataColumn[], Boolean)

Initializes a new instance of the DataRelation class using the specified name, matched arrays of parent and child columns, and value to create constraints.

[Visual Basic]
Overloads Public Sub New( _
   ByVal relationName As String, _
   ByVal parentColumns() As DataColumn, _
   ByVal childColumns() As DataColumn, _
   ByVal createConstraints As Boolean _
)
[C#]
public DataRelation(
   string relationName,
   DataColumn[] parentColumns,
   DataColumn[] childColumns,
   bool createConstraints
);
[C++]
public: DataRelation(
   String* relationName,
   DataColumn* parentColumns[],
   DataColumn* childColumns[],
   bool createConstraints
);
[JScript]
public function DataRelation(
   relationName : String,
   parentColumns : DataColumn[],
   childColumns : DataColumn[],
   createConstraints : Boolean
);

Parameters

relationName
The name of the relation. If a null reference (in Visual Basic Nothing) or an empty string (""), a default name will be given when the created object is added to the RelationsCollection.
parentColumns
An array of parent DataColumn objects.
childColumns
An array of child DataColumn objects.
createConstraints
A value indicating whether constraints are created. true, if constraints are created, otherwise, false.

Exceptions

Exception Type Condition
ArgumentNullException Either one or both of the DataColumn objects is a null reference (Nothing).
InvalidConstraintException The columns have differing data types

-Or-

The tables don't belong to the same DataSet.

Example [Visual Basic]

The following example creates a new DataRelation and adds it to a DataSet object's RelationsCollection.

[Visual Basic]

Private Sub CreateRelation()
   ' Get the DataColumn objects from two DataTable objects in a DataSet.
   Dim parentCols() As DataColumn
   Dim childCols() As DataColumn
   ' Code to get the DataSet not shown here.
   Set parentCols(0) = DataSet1.Tables("Customers").Columns("CustID")
   Set parentCols(1) = DataSet1.Tables("Customers").Columns("OrdID")

   Set childCols(0) = DataSet1.Tables("Orders").Columns("CustID")
   Set childCols(1) = DataSet1.Tables("Orders").Columns("OrdID")

   Dim bConstraints As Boolean
   bConstraints = True
   ' Create DataRelation.
   Dim relCustOrder As DataRelation
   Set CustOrderRel = New DataRelation("CustomersOrders", parentCols, childCols, bConstraints)
   ' Add the relation to the DataSet.
   DataSet1.Relations.Add(CustOrderRel)
End Sub

See Also

DataRelation Class | DataRelation Members | System.Data Namespace | DataRelation Constructor Overload List | DataColumn | ForeignKeyConstraint | RelationName