How to get inserted row immediately after query execution in cassandra?

Question

I am trying to get last inserted row in cassandra but I am getting undefined

Here is how code looks for insert:

const cassandra = require('cassandra-driver');
const client = new cassandra.Client({ contactPoints: ['h1', 'h2'], keyspace: 'ks1' });

let query = "INSERT INTO users (id, name, email ) values (uuid(), ?, ?)";

client.execute(query, [ 'badis', 'badis@badis.com' ])
  .then(result => console.log('User with id %s', result.rows[0].id));

What does the primary key definition on your table look like? — Aaron, May 03 '18 at 18:17
@Aaron sorry if my question was not clear enough. but everything is well structured and works for `select`. my issue is I want to get `id` and other infos of new inserted row. — Badis Merabet, May 03 '18 at 19:03
I am getting this error: `(node:8140) UnhandledPromiseRejectionWarning: TypeError: Cannot read property '0' of undefined` — Badis Merabet, May 03 '18 at 19:10
So the error suggests that either result.rows doesn't exist or it is not an array. Could you console.log `result` and post back what you get? — Mike Rudge, May 05 '18 at 21:17

score 6 · Accepted Answer · answered May 06 '18 at 00:43

Remember you are dealing with NoSQL ("non relational")

If I were to run a SELECT * FROM users LIMIT 1 on this table, my result set would contain a single row. That row would be the one containing the lowest hashed value of username (my partition key), because that's how Cassandra stores data in the cluster. I would have no way of knowing if it was the last one added or not, so this wouldn't be terribly useful to you.

The workings are very different from those that you might be used to in MySQL.

If obtaining the last inserted row's information is needed for your system, then you will have to know it before you insert it.

Generating UUID

const Uuid = require('cassandra-driver').types.Uuid;
const id = Uuid.random();

Then you can use the id as another value for the prepared insert query

const cassandra = require('cassandra-driver');
const client = new cassandra.Client({ contactPoints: ['h1', 'h2'], keyspace: 'ks1' });

let query = "INSERT INTO users (id, name, email ) values (?, ?, ?)";

client.execute(query, [id, 'badis', 'badis@badis.com' ])
  .then(result => console.log('User with id %s', id));

Thank you ! does the generate Uuid is unique across all tables and across time ? — Badis Merabet, May 07 '18 at 16:50

How to get inserted row immediately after query execution in cassandra?

1 Answers1