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AcceptRejectRule Enumeration
Determines the action that occurs when the AcceptChanges or RejectChanges method is invoked on a DataTable with a ForeignKeyConstraint.
Members
| Member Name | Description |
|---|---|
| Cascade | Changes are cascaded across the relationship. |
| None | No action occurs. |
Remarks
Changes to a DataTable are not final until you call the AcceptChanges method. At that time, constraint-related errors can occur because any ForeignKeyConstraint objects associated with a DataTable are activated to allow deletions and edits to occur freely. Prior to that time, ForeignKeyConstraint objects are inactive. When the ForeignKeyConstraint becomes activated, and errors occur, AcceptRejectRule is called to determine the next course of action.
If changes to a DataTable are rejected, using the RejectChanges method, AcceptRejectRule is called to determine how changes to the relationship are rolled back.
Example
The following example initializes a ForeignKeyConstraint, sets some of its various properties, including the AcceptRejectRule, and adds it to a DataTable object' s ConstraintCollection.
private void SetConstraint ( DataSet myDataSet, string table1,
string table2, string column1, string column2 ) {
// declare parent column and child column variables.
DataColumn parentColumn;
DataColumn childColumn;
ForeignKeyConstraint myFKeyConst;
// set parent and child column variables.
parentColumn = myDataSet.Tables [ Table1 ].Columns [ Column1 ];
childColumn = myDataSet.Tables [ Table2 ].Columns [ Column2 ];
myFKeyConst = new ForeignKeyConstraint
( "SupplierFKeyConst", parentColumn, childColumn );
// set null values when a value is deleted.
myFKeyConst.DeleteRule = Rule.SetNull;
myFKeyConst.UpdateRule = Rule.Cascade;
myFKeyConst.AcceptRejectRule = AcceptRejectRule.Cascade;
// add the constraint, and set EnforceConstraints to true.
myDataSet.Tables [ Table1 ].Constraints.Add ( myFKeyConst );
myDataSet.EnforceConstraints = true;
}
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| C# | VB | |
See Also
Constraint ConstraintCollection ForeignKeyConstraint Rule UniqueConstraint
