Support for joins

Is there an eta on when joins will be supported?

Hi MetalAZ,

We have no firm plans to support joins at this stage. While this may sound bad initially, you should find that you can perform queries that return the same data by using the Exists() method with LightSpeed.

Appreciate any feedback you have about this - perhaps you could give me an example of the query you're trying to perform?

If it's a particularly hardcore query that you're writing then perhaps you could leverage the stored procedure support available in the nightly builds of LightSpeed?

I hope that helps,

John-Daniel

Using a stored procedure would be great -- that's what I had originally had wanted to do.  I just updated to the nightly build and tried to use a stored procedure and had the exception "The MySql5 data provider does not support stored procedure queries".

Are procs not supported with MySql yet?

Thanks,

Greg

Hello Greg,

Stored procedures are not yet supported on MySQL, but this is simply due to not having got round to it rather than due to any inherent issue or intent.  I'll try to get this added this week for you, and post here when it becomes available.

Hello Greg,

Basic support for MySQL stored procedures will be in nightly builds dated 6 Jan 2008 and above, available from about 1430 GMT.  See http://www.mindscape.co.nz/blog/index.php/2008/10/20/stored-procedures-and-lightspeed/ for how to use sprocs (MySQL sprocs use the SQL Server style select-as-return rather than the Oracle results parameter convention).  There are currently some limitations around scalar procedures (the IUnitOfWork.Calculate method) which appear to be a MySQL issue but I will investigate further; sprocs that return row sets (which map to entities) should be okay.

In this build, we only have MySQL sproc support in the runtime.  I will be looking at adding drag-and-drop support to the designer over the next couple of days. 

 Works great!

 Ivan,

I have my application ported over from straight LINQ to SQL using ASP.NET MVC to using  Lightspeed. I *really* like how the code works and how it got me thinking (and solving) solutions to problems that haven't yet surfaced. Fantastic job.

The one limiting factor left for me is the lack of joins and group bys. I have a lot of LINQ queries already working and tested, and I'd rather not go through the process of converting LINQ back to the database (via views or SPs).

Is there any possibility of getting this bumped up on the radar over there?

Thanks much.

Dan Miser

Hi Dan,

Thank you for the kind words.

We have some limited work on join support planned in for 2.2, but we don't yet know whether this is going to extend as far as the LINQ Join operator.

It would be really useful to us if you could elaborate on the kind of queries you need to do using joins and group bys.  Full join and group-by support is probably a way off, because it involves potentially substantial extensions to the core query engine as well as all the LINQ bits to go around that; but it may be that we can deliver a limited subset more quickly which will meet the majority of your needs.  We can't promise anything but we would be happy to explore this with you.

By the way, we have made some improvements to the dynamic data support over the last week or so, so if you are looking at having a go with that then I'd encourage you to upgrade to the latest nightly. 

Ivan,

If you want to send me an email to dmiser@wi.rr.com, I can put together a sample schema and some LINQ queries to see if the subset approach will work.

Thanks much.

Here is one more vote for supporting joins.

In fact, lack of support for joins will probably turnout to be the only solid reason for us not to use Lightspeed at the moment and use another option (dotConnect for Oracle from Devart).
In short, with our product's vision and requirements we want to prepare screen based DTOs by using LINQ and joins to balance development complexity and query speed (and I'm not very fond of the idea of making my developers use eager loading named aggregate concept).

I still like your product though, it's very slick. I will keep an eye out on 3.0. Maybe we'll have some more delays on our projects (damn recession :( ) and we'll manage to fit it in when it comes out eventually.

Thanks in advance! 

Hi Juan,

LightSpeed 3.0 will have join and group by capabilities - we're currently fleshing out the missing parts of our LINQ provider. We will likely start providing beta versions of LightSpeed 3.0 around mid year - with a plan to release the final version shortly after that.

This should mean that if you pick LightSpeed today you won't have to wait long for the capabilities you require - we'd love to have you onboard.

I hope that helps - please let me know if there are any other questions you have.

John-Daniel Trask