CODEWITHSUNDEEP
cassandradata-modeling
ts178
ts178

Reputation: 329

Cassandra Data Modeling : Dynamic column

I have a table user_activity.

user_activity
{
user_id text
user_name text
email_id text
password text
activity1 text}

Is it possible to add column dynamically?

for ex -

user1(user_id : Rowkey)

user_name, emai_id, password, activity1, activity2 

user2(user_id : Rowkey)

user_name, emai_id, password, activity1, activity2, activity3

user3(user_id : Rowkey)

user_name, emai_id, password, activity1

since activities could be of any number.

thanks in advance :)

Upvotes: 1

Views: 131

Answers (1)

Ashraful Islam
Ashraful Islam

Reputation: 12830

You can use Map

For example : 

CREATE TABLE user_activity (
    user_id text primary key,
    emai_id text,
    password text,
    activity map<text,text>
);

Insert :

INSERT INTO user_activity (user_id, emai_id, password, activity) VALUES ('1', '[email protected]','password1', {'activity1'  : 'test activity 1', 'activity2' : 'test acitivty 2' });

Update : 

UPDATE user_activity SET activity['activity1'] = 'updated test activity 1' where user_id = '1';

Delete : 

DELETE activity['activity2'] FROM user_activity WHERE user_id = '1';

Note : Keep the collection (map) size small, In Cassandra for map Maximum number of keys: 65535 and values size: 65535

Upvotes: 1

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