System.Data (system.data.dll) |
enum |
This enumeration is used to specify two properties of the
ForeignKeyConstraint class:
ForeignKeyConstraint.UpdateRule and
ForeignKeyConstraint.DeleteRule . The value from
this enumeration indicates what will happen to the related child rows
when a change is made to a parent row. For example, by using a
ForeignKeyConstraint.DeleteRule or
Cascade , all child rows are removed when the
parent row is deleted. If you use SetNull , the
foreign key field in the child record is set to a
null value. SetDefault restores
the default value for the foreign key field; None
performs no action.
public enum Rule {
None = 0,
Cascade = 1,
SetNull = 2,
SetDefault = 3
}
Hierarchy
System.Object
System.ValueType System.Enum(System.IComparable, System.IFormattable
, System.IConvertible)
Rule
Returned By
ForeignKeyConstraint.{DeleteRule
, UpdateRule}
Passed To
ForeignKeyConstraint.{DeleteRule
, ForeignKeyConstraint( )
, UpdateRule}
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