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How to make derived propeties persistent

Technically, derived properties can not be persistent. But their values can be derived from persistent field properties, making them behave like they are persistent.

The most common example of this is the implementation of navigation over a relationship by a derived or multi value property. In example 2 the derived property Hours>>employee returns an instance of Employee whose 'id' is equal to the value of Hours>>employeeId. See  how to add relationship navigation.

A different example is the property Employee>>name whose value is derived from persistent field properties 'firstName' and 'lastName'. See example 1.