[mouse_catcher]

Hi All

I will be starting development of Software as a Service (SaaS) application early in the new year and I am trying to decide on the architecture and frameworks at the moment.

Currently I'm thinking of using NHibernate as an ORM (Object Relational Mapper) and I see that it has support for mysql. I've got zero experience with mysql because I'm a sql server guy but if NHibernate handles the data access layer I'm thinking it would be a lot cheaper to go with mysql.

Anybody had experience with NHibernate with mysql? How about just NHibernate - is it easily maintainable once the system goes live?

I know Linq to sql is out now but I've heard its a lightweight framework - any positive or negative feedback (yeah I'm looking at you Catalyst )?

[Catalyst]

I guess it depends on what you want your ORM to do for you. I wrote my own ORM code generating tool that I've been using while I waited for LINQ to come out because the existing ORMs either didn't do quite what I wanted or they were going to take weeks to learn to use. I started digging into nHibernate a while back and it's very robust but I think it's got a bigger learning curve than LINQ and the project configuration takes enough work that you might avoid using it for small projects.

There's no question for me that LINQ is my choice for ORM. And a benefit to LINQ is you can use it along with nHibernate if you want. So my suggestion is that you try LINQ and if you find that it doesn't do everything you need for this project then you'll still have it as an easy option for other ones. I also think that the integration with VS and the support of MS make LINQ a good choice.

I've got a LINQ book on order so I should know a lot more about it shortly.

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I'm thinking it would be a lot cheaper to go with mysql.

I've used both mysql and MSSql for a while and I'd never choose mysql if I had a choice. I've come up against too many limitations and dealt with enough corrupt mysql databases that it's just left a bad taste. SQL Express is free and it's robust enough that I run commercial sites using it. It limited to only using 1 processor and a max db size of 4GB but I haven't built anything that comes close to needing more than that. And again you've got all the builtin tools, debuggers, etc with VS.

[Catalyst]

I new there was another ORM I was going to suggest looking at and it finally came to me, SubSonic.
http://www.subsonicproject.com/

[mouse_catcher]

Catalyst, on Dec 2 2007, 10:33 AM, said:

I've used both mysql and MSSql for a while and I'd never choose mysql if I had a choice. I've come up against too many limitations and dealt with enough corrupt mysql databases that it's just left a bad taste.

Good to know I've been spoiled. Thanks for the warning on the mysql front. It'll save me time on the R & D front (read; won't go near it with a 10ft pole)

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I've got a LINQ book on order so I should know a lot more about it shortly.

I'd be very interested to know how this goes once you grok it. I've seen the basic stuff in action but It's always those edge cases that really stuff me up. In my case its a multi-tenanted database that needs some pretty rock solid isolation between tenants.

[Catalyst]

I'm just a chapter in, but so far I've got a few thoughts about LINQ. I'll put some bigger separate posts up as I get further along.

First off, it's a LOT more than an ORM and something I'll be using frequently for things that aren't even database related. For example you can use LINQ to return elements from an array.

Second, and more to your comments, there are two ORMish aspects of LINQ. LINQ to SQL is the one that you see the majority of the articles about, and it's a simpler, lighter framework. The other one, LINQ to Entities is the potentially more powerful (but also more complex) framework. So if edge cases are a concern you might want to look into that specific aspect of LINQ to see how it meets your needs. And LINQ to nHibernate is another road to explore.

It's going to be very strange to not be thinking in SQL all the time.

[Bronzytalk]

Hi ,
I don't know much about NHibernate. But I can find some information about this.NHibernate not only takes care of the mapping from .NET classes to database tables but also provides data query and retrieval facilities and can significantly reduce development time in SQL and ADO.NET. NHibernate may not be the best solution for data-centric applications that only use stored-procedures to implement the business logic in the database. I did not find a lot of information on using NHibernate in combination with a MySQL database. If you know some more information about this please share us because its helpful to all who is new to this.