Database Reference
In-Depth Information
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
com-
mand, except that we need not specify the column's type; only its name is sufficient. Look-
ing 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 contents of the
table:
SELECT * FROM "users";
The output now includes our new
location
column: