How to get the number of groups by issuing a separate query after group by? about jinq HOT 3 CLOSED

I’ve never used Spanner, and I’m not sure if Jinq even works with Spanner. But assuming Spanner is supposed to work like SQL, then you can

• use distinct and then count to count the number of groups http://www.jinq.org/docs/queries.html#N67275
• if you’re using a query to fetch the groups anyway, then once you’ve called toList() to execute the query and store the results in memory, then just call size() to get the number of groups.

from jinq.

Thank you for your help.

from jinq.

Sharing my experience, I am collecting information and have not verified it yet.
Spanner database supports PostgreSQL dialect, and PostgreSQL supports the method of obtaining the total number of records.
It may be used to solve the problem of getting the total number of the groups.

from jinq.