find a entity with another entity.

Signed-off-by: Flycoding <Flycoding@yeah.net>
using extends in xml Mapper file to simplify the configuration.

Signed-off-by: Flycoding <Flycoding@yeah.net>
select multiple rows data with details(student with address).

Signed-off-by: Flycoding <Flycoding@yeah.net>
using nested resultMap.

Signed-off-by: Flycoding <Flycoding@yeah.net>