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Posted to user@cassandra.apache.org by Tony Anecito <ad...@yahoo.com> on 2013/06/25 17:02:38 UTC

Is nexted selects supported by Cassandra JDBC??

Hi All,

Is nested select supported by Cassandra JDBC driver?

So for a simple example to get a list of user details from a users column family:

Select * from user_details where user_id in (Select user_id from users)

Thanks!
-Tony

Re: Is nexted selects supported by Cassandra JDBC??

Posted by Job M Thomas <jo...@yahoo.com>.

Please read the below blog 

Cassandra : Sub-Query Implementation

http://cassandrapowerfulnosql.blogspot.in/2015/03/sub-query-in-
cassandra.html

Re: Is nexted selects supported by Cassandra JDBC??

Posted by Sylvain Lebresne <sy...@datastax.com>.

Yes, denormalization is usually the answer to the absence of sub-queries
(and joins for that matter) in Cassandra (though sometimes, simply doing 2
queries is fine, depends on your use case and performance requirements).


On Tue, Jun 25, 2013 at 6:46 PM, Tony Anecito <ad...@yahoo.com> wrote:

> Ok. So if I have a composite key table instead of a nested select I will
> have to run 2 queries else denormalize? Unless there is something provided
> by CQL 3 to do the same thing?
>
> Thanks,
> -Tony
>
>
>   ------------------------------
>  *From:* Sylvain Lebresne <sy...@datastax.com>
> *To:* "user@cassandra.apache.org" <us...@cassandra.apache.org>; Tony
> Anecito <ad...@yahoo.com>
> *Sent:* Tuesday, June 25, 2013 9:06 AM
> *Subject:* Re: Is nexted selects supported by Cassandra JDBC??
>
> No. CQL3 doesn't support nested selects.
>
> --
> Sylvain
>
>
> On Tue, Jun 25, 2013 at 5:02 PM, Tony Anecito <ad...@yahoo.com> wrote:
>
> Hi All,
>
> Is nested select supported by Cassandra JDBC driver?
>
> So for a simple example to get a list of user details from a users column
> family:
>
> Select * from user_details where user_id in (Select user_id from users)
>
> Thanks!
> -Tony
>
>
>
>
>

Re: Is nexted selects supported by Cassandra JDBC??

Posted by Tony Anecito <ad...@yahoo.com>.

Ok. So if I have a composite key table instead of a nested select I will have to run 2 queries else denormalize? Unless there is something provided by CQL 3 to do the same thing?

Thanks,
-Tony

________________________________
 From: Sylvain Lebresne <sy...@datastax.com>
To: "user@cassandra.apache.org" <us...@cassandra.apache.org>; Tony Anecito <ad...@yahoo.com> 
Sent: Tuesday, June 25, 2013 9:06 AM
Subject: Re: Is nexted selects supported by Cassandra JDBC??

No. CQL3 doesn't support nested selects.

--
Sylvain

On Tue, Jun 25, 2013 at 5:02 PM, Tony Anecito <ad...@yahoo.com> wrote:

Hi All,
>
>
>Is nested select supported by Cassandra JDBC driver?
>
>
>So for a simple example to get a list of user details from a users column family:
>
>
>Select * from user_details where user_id in (Select user_id from users)
>
>
>Thanks!-Tony

Re: Is nexted selects supported by Cassandra JDBC??

Posted by Sylvain Lebresne <sy...@datastax.com>.

No. CQL3 doesn't support nested selects.

--
Sylvain


On Tue, Jun 25, 2013 at 5:02 PM, Tony Anecito <ad...@yahoo.com> wrote:

> Hi All,
>
> Is nested select supported by Cassandra JDBC driver?
>
> So for a simple example to get a list of user details from a users column
> family:
>
> Select * from user_details where user_id in (Select user_id from users)
>
> Thanks!
> -Tony
>