CQL for Cassandra 2.0

Using lightweight transactions

INSERT and UPDATE statements using the IF clause, support lightweight transactions, also known as Compare and Set (CAS).

Procedure

  1. Register a new user.
    INSERT INTO users (login, email, name, login_count)
    VALUES ('jdoe', 'jdoe@abc.com', 'Jane Doe', 1)
    IF NOT EXISTS
  2. Perform a CAS operation against a row that does exist by adding the predicate for the operation at the end of the query. For example, reset Jane Doe's password.
    UPDATE users
    SET email = ‘janedoe@abc.com’
    WHERE login = 'jdoe'
    IF email = ‘jdoe@abc.com’