Changes between Version 49 and Version 50 of FDORfc33


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Timestamp:
Apr 20, 2009, 12:19:27 PM (15 years ago)
Author:
gregboone
Comment:

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  • FDORfc33

    v49 v50  
    4848In cases where the resulting columns come from an existing FDO feature table, a provider can return the class definition corresponding to that table. In cases where the columns come from an unknown table, a class definition can be constructed on the fly. By definition, the FDO class definition returned by a feature reader does not necessarily correspond exactly to an existing FDO class definition. Existing class definitions may contain the properties that were asked for in the Select command, plus additional computed properties. It is perfectly legal to return a constructed class definition, which is only valid for the select that was executed, and not usable for further updates or inserts.
    4949
    50 In the circumstance that a computed class is generated, the FDO class definition’s !IsComputed property will return true. In that manner, applications are able to distinguish the content of the feature reader responses coming from the providers and tailor their implementation accordingly. In such a situation, some care will also need to be given to the name of the generated schema and classes. At this point no standards exist for naming auto-generated or comuted schema, class and property names. It would be beneficial if, as a result of this RFC, some uniform conventions could be adopted.
    51 
    52 Providers that do return feature readers from SQL commands will need to come up with the appropriate class definition that the feature reader could expose. Here are a few general use cases that can be used to guide their implementations:
     50In the circumstance that a computed class is generated, the FDO class definition’s !IsComputed property will return true. In this manner, applications are able to distinguish the content of the feature reader responses coming from the providers and tailor their implementation accordingly. In such a situation, some care will also need to be given to the name of the generated FDO schema and class definitions. At this point no standards exist for naming auto-generated schema, class and property names. It would be beneficial if, as a result of this RFC, some uniform naming conventions could be adopted.
     51
     52Providers that do return feature readers from SQL commands will need to come up with the appropriate class definition that the feature reader could expose. Here are a few general use cases that should be used to guide provider implementation:
    5353
    5454    - Select is against a table that has an existing class definition and the select returns the same information as defined by the class definition (e.g. select * from roads).