XPO Classes Comparison
时间:2010-09-09 来源:Elvin Chen
XPO Classes Comparison |
eXpress Persistent Objects > Feature Center > Data Representation > XPObject > XPO Classes Comparison
There are four classes from which you can derive your persistent objects. These are: XPBaseObject, XPObject, XPLiteObject and XPCustomObject.
Deriving from any class automatically enables various XPO features for your persistent object. For example, when creating a persistent object by deriving from the XPBaseObject, XPCustomObject or XPObject class, an OptimisticLockingAttribute is automatically applied to it. This enables the optimistic locking feature. If your persistent class derives from the XPLiteObject class, the optimistic locking feature is disabled.
The table below shows the difference between the XPO classes.
Class Name | Deferred Deletion | Optimistic Locking | Built-in OID key |
---|---|---|---|
XPBaseObject | - | + | - |
XPLiteObject | - | - | - |
XPCustomObject | + | + | - |
XPObject | + | + | + |
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