| Value | Meaning |
|---|---|
| noAction | When a parent key is modified or deleted from the collection, no special action is taken. If you are using MySQL or MSSQL use $(SRCTAG Rule.restrict) instead for the desired effect. |
| restrict | The item is prohibited from deleting or modifying a parent key when there exists one or more child keys mapped to it. This is the default. $(THROWS ForeignKeyException, when a member changes.) |
| setNull | Sets the member to null when deleting or modifying a parent key. $(THROWS ForeignKeyException, when the type cannot be set to null.) |
| setDefault | Sets the member to the Default value when deleting or modifying a parent key. If there is no defined Default then the member is set to its types initial value. |
| cascade | Updates or deletes the item based on what happened to the parent key. |
Rules for foreign keys when updating or deleting.