Updating the existing rows
Now that we've got a new location
column, we can add some data to it. Any new user records we create, of course, can have a location
value, but perhaps some of our existing users would like to input their location
value too. To do this, we need to be able to update existing rows. The process should, once again, look quite familiar to anyone who is familiar with SQL:
UPDATE "users" SET "location" = 'New York, NY' WHERE "username" = 'alice';
Like the INSERT
and DELETE
statements, the UPDATE
statement does not give us any feedback on the operation. However, we can confirm it worked by reading from the users
table again:
SELECT * FROM "users";
As we hoped, alice
now has a location:
Note
A full reference for the UPDATE
statement can be found in the DataStax CQL documentation at http://www.datastax.com/documentation/cql/3.1/cql/cql_reference/update_r.html
Updating multiple columns
As in the SQL UPDATE
statement, we can specify multiple column-value pairs to be updated in a...