DS201: How to get value of "type timeuuid" while inserting into cassandra using Python Driver?

Question

This is my first query on the forum so please correct if my understanding are wrong.

I am executing exercise Application Driver Connection from DS201.

Table is as follows:

cqlsh:killrvideo> SELECT * FROM videos_by_tag ;

       tag | added_date                      | video_id                             | title
-----------+---------------------------------+--------------------------------------+------------------------------  
  datastax | 2013-10-16 00:00:00.000000+0000 | 4845ed97-14bd-11e5-8a40-8338255b7e33 | DataStax Studio

Now I want to do one task "Python code to insert a new video into the database" as per lab.

I tried this code and getting error:

>>> session.execute(
... "INSERT INTO videos_by_tag (tag, added_date, video_id, title)" +
... "VALUES ('cassandra', '2013-01-10', uuid(), 'Cassandra Is My Friend')")

Traceback (most recent call last):
File "<stdin>", line 3, in <module>
File "cassandra/cluster.py", line 2618, in cassandra.cluster.Session.execute
File "cassandra/cluster.py", line 4877, in cassandra.cluster.ResponseFuture.result
cassandra.InvalidRequest: Error from server: code=2200 [Invalid query] message="Type error: cannot assign result of function system.uuid (type uuid) to video_id (type timeuuid)"
>>>

I tried below but failed:

1. UUIDs.timeBased()

ERROR:

cassandra.InvalidRequest: Error from server: code=2200 [Invalid query] message="Unknown function uuids.timebased called"

2. cassandra.util.uuid_from_time

ERROR:

cassandra.protocol.SyntaxException: <Error from server: code=2000 [Syntax error in CQL query] message="line 1:109 no viable alternative at input '.' (...)VALUES ('cassandra', '2013-01-10', [cassandra].util...)">

For time being I have hardcoded the value.

session.execute(
... "INSERT INTO videos_by_tag (tag, added_date, video_id, title)" +
... "VALUES ('cassandra', '2013-01-10', 245e8024-14bd-11e5-9743-8238357b7e32, 'Cassandra Is My Friend')")

Success in DB:

cassandra | 2013-01-10 00:00:00.000000+0000 | 245e8024-14bd-11e5-9743-8238357b7e32 | Cassandra Is My Friend

But I want to know this ?

Answer 1

You are correct in that the call to the uuid() function is your problem:

INSERT INTO videos_by_tag (tag,added_date,video_id,title)
VALUES ('cassandra', '2013-01-10', uuid(), 'Cassandra Is My Friend');

The uuid() function generates a type-4 UUID, whereas the video_id column is defined as a type-1 UUID (aka a TIMEUUID).

Instead, invoke the now() function to get a TIMEUUID:

INSERT INTO videos_by_tag (tag,added_date,video_id,title)
VALUES ('cassandra', '2013-01-10', now(), 'Cassandra Is My Friend');