| 321 | | At FdoISelect::Execute time a feature reader will be returned, even though there might be cases when the join class returned by the reader contains a primary key or a geometry column. In cases where select commands do not provide a property selection list, all columns will be added to the feature class reader built at runtime. In cases where users request a subset of properties, only those properties will be added to the feature class, even if that means the returned feature class might then contain no primary key or no geometry properties. This behaviour will be implemented due to the fact that a feature reader, even one that does not contain primary key or geometry properties, is very useful in applications. In the worst case, the implementation can add all primary keys from the selected classes to the result primary key of the joined class definition. Also, in case there is no way to return a primary key, users can add one of the property to the primary key collection of the returned class to allow a primary key to be defined. NOTE that the returned class will be read-only since there is no way to know if the resulting class can be updated. |
| | 321 | At FdoISelect::Execute time a feature reader will be returned, even though there might be cases when the join class returned by the reader will not contain a primary key or a geometry property. In cases where select commands do not provide a property selection list, all properties can be added to the feature class reader built at runtime. In cases where users request a subset of properties, only those properties will be added to the feature class, even if that means the returned feature class might then contain no identity properties or geometry properties. This behaviour will be implemented due to the fact that a feature reader, even one that does not contain primary key or geometry properties, is very useful in applications. In the worst case, a provider implementation can add all identity properties from the selected classes to the resulting identity property list of the joined class definition. Also, in case there is no way to return an identity property, providers can add a non-identity property to the identity ptroperty collection of the returned class as a shortcut to allow a primary key to be defined. NOTE that the returned class will be read-only since there is no way to know if the resulting class can be updated. |
