Database Reference
In-Depth Information
Consider a scenario where the user wants to store only a collection of follower's id (not
full name). Cassandra offers collection support for keeping a
list
or
set
of such ele-
ments. Let's discuss how to implement it using
set
support.
1.
First, let's create a keyspace
twitter
and column family
users
.
create keyspace twitter with replication =
{'class':'SimpleStrategy','replication_factor':3};
use twitter;
create table users(twitter_id text primary
key,followers set<text>);
2.
Store few columns in
users
column family for row key value
'im-
vivek'
.
insert into users(twitter_id,followers)
values('imvivek',
{'guestuser','ritaf','team_marketing'});
Here we are adding followers as dynamic columns as set attributes for
user
imvivek
.
3.
Let's add the following:
'imvivek'
and
'team_marketing'
as followers for
'ritaf'
'ritaf'
as a follower for
'jhassell'
insert into users(twitter_id,followers)
values('ritaf',
{'imvivek','jhassell','team_marketing'});
insert into users(twitter_id,followers)
values('jhassell', {'ritaf'});
4.
To view the list of rows in
users
column family (see
Figure 2-10
), use
the following command:
select * from users;
