Deleting columns
Upon further consideration, we may decide that location
is a better column name than city_state
. Cassandra does not allow us to rename existing data columns; however, since we haven't put any data in the city_state
column yet, we can achieve our goals simply by dropping the city_state
column and adding a location
column instead:
ALTER TABLE "users" DROP "city_state"; ALTER TABLE "users" ADD "location" text;
The DROP
command within the ALTER TABLE
statement looks just like the ADD
command, except that we need not specify the column's type; only its name is sufficient. Looking at the output of DESCRIBE
again, we've now got the columns set up the way we'd like:
Now that we've got our expanded schema, we can take a look at the actual ...
Get Learning Apache Cassandra now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.