Learning Apache Cassandra - Second Edition

Counting rows

While, in some cases, it might be fine to simply keep requesting pages until no more records are encountered, it's often nice to give the user a sense of how many records they're dealing with up front. Happily, we can use the COUNT function to do just this:

SELECT COUNT(1) FROM "user_status_updates"WHERE "username" = 'alice';

Instead of requesting a list of columns or a wildcard to get all columns, we select COUNT(1) to get a total count of rows matching the WHERE condition:

We could have also used COUNT(*), which behaves in the same way as COUNT(1). There are, however, no other valid ways to use the COUNT function in CQL. ...