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Cassandra CQL3 conditional insert / update

I have a list of unordered events, and my task is to keep the first and last occurrences for them.

I have the following column family in Kassandra:

CREATE TABLE events (
   event_name TEXT,
   first_occurrence BIGINT,
   last_occurrence BIGINT,
   PRIMARY KEY (event_name)
);

So, if I have an event with the name "some_event" and an appearance with 123456, then I want to do something that in terms of MySQL will look like this:

INSERT INTO events (event_name, first_occurence, last_occurence)
VALUES ('some_event', 123456, 123456)
ON DUPLICATE KEY UPDATE 
     first_occurrence = LEAST(first_occurrence, 12345), 
     last_occurrence = GREATEST(last_occurrence, 123456)

I was going to use lightweight transactions in Kassandra to accomplish this, for example:

INSERT INTO events(event_name, first_occurrence, last_occurrence) VALUES ('some_event', 12345, 12345) IF NOT EXISTS;
UPDATE events SET first_occurrence = 123456 WHERE event_name='some_event' IF first_occurrence > 123456;
UPDATE events SET last_occurrence = 123456 WHERE event_name='some_event' IF last_occurrence < 123456;

But, as it turned out, CQL3 does not allow <and> in an IF statement with a lightweight transaction.

So my question is: what is the pattern for doing such conditional updates?

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2 answers

? LWT ​​ 2.1.1 CASSANDRA-6839:

cqlsh:test> UPDATE events SET first_occurrence = 123456 WHERE event_name='some_event' IF first_occurrence > 1;

[applied]
-----------
  True
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