Updating datastore snippets (#338)
Updating datastore snippets (#338)

* Using Query.key_filter(), fixes #198
* Using Query.distinct_on instead of group_by.

Change-Id: I3ad2cad1fb60ca7db4b887b9f58481e7b5bc4a1c
GoogleCloudPlatform/python-docs-samples,JavaRabbit/CS496_capstone,canglade/NLP,canglade/NLP,canglade/NLP,sharbison3/python-docs-samples,canglade/NLP,GoogleCloudPlatform/python-docs-samples,GoogleCloudPlatform/python-docs-samples,BrandonY/python-docs-samples,sharbison3/python-docs-samples,hashems/Mobile-Cloud-Development-Projects,BrandonY/python-docs-samples,JavaRabbit/CS496_capstone,JavaRabbit/CS496_capstone,sharbison3/python-docs-samples,hashems/Mobile-Cloud-Development-Projects,JavaRabbit/CS496_capstone,hashems/Mobile-Cloud-Development-Projects,sharbison3/python-docs-samples,BrandonY/python-docs-samples,GoogleCloudPlatform/python-docs-samples,hashems/Mobile-Cloud-Development-Projects,BrandonY/python-docs-samples