Doesn't work with XtraGrid server mode
Joined: 22-Mar-2006
Actually there is an exception (I didn't catch it before because I've turned out caching external exceptions 
)
The good news is that it doesn't look like LINQ to LLLBLGenPro bug - instead LinqServerModeSource is trying to select ObjectID column from database for some reason:
The property 'ObjectID' isn't mapped to a field or database construct of entity type 'CustomersEntity'. Did you mean to call an extension method instead? ('Count' vs. 'Count()') ?
Not sure why the same provider works with LINQ to SQL - perhaps L2S is ignoring invalid columns?
AH 
This is what I expected: they use reflection and simply add a filter on every property. You get the same exception when you do this: var q = from c in metaData.Customer select c.Orders.Count;
Here, 'Count' is the property of the 'Orders' collection, not the extension method Count(). So the provider has no idea what to do with it, as it's not mapped onto a method or a db field or anything, so it gives up.
Entity types have 'ObjectID' as a property (and other properties as well). These properties are all marked as 'Browsable(false)', with the browsable attribute.
Two things can be done: 1) I can ignore the properties, but that's not always easy: in the above query: what should the query do? So it's not always ignorable and KEEP the query as-is. or 2) They can filter out properties which are marked as Browsable(false). Or use ITypedList if possible, as that's going to give you the right results.
Linq to Sql doesn't have this as their entity classes don't have properties which aren't mapped onto a db field, and their entityset properties are mapped onto methods (e.g. 'Count' is mapped onto Count()) I think you can get the same kind of error from linq to sql if you add a custom property in code which is returning another property in the entity.
Right. In the meantime I am keeping them busy on this issue as well .
mihies wrote:
Right. In the meantime I am keeping them busy on this issue as well
Do you have an URL for me on their forums about this issue so I can post there if necessary?
Thanks for the hard work in this btw!
Otis wrote:
mihies wrote:
Right. In the meantime I am keeping them busy on this issue as well
Do you have an URL for me on their forums about this issue so I can post there if necessary?
If you are a customer use Support Center http://www.devexpress.com/support/center/ or alternatively you can send an e-mail to support@devexpress.com. (you can also reference issue i posted http://www.devexpress.com/support/center/p/B92896.aspx). Forums are mostly peer to peer.
mihies wrote:
Otis wrote:
mihies wrote:
Right. In the meantime I am keeping them busy on this issue as well
Do you have an URL for me on their forums about this issue so I can post there if necessary?
If you are a customer use Support Center http://www.devexpress.com/support/center/ or alternatively you can send an e-mail to support@devexpress.com. (you can also reference issue i posted http://www.devexpress.com/support/center/p/B92896.aspx). Forums are mostly peer to peer.
Hmm...
I'll send them an email referring this thread and your bugreport. I definitely want to know what the reason is for this weird query.
Joined: 22-Mar-2006
DvK wrote:
Heh thanks for the support, Danny
I'm sure it's solvable, after all the query is pretty weird, so I'm sure it's fixable into a more appropriate query.
Joined: 22-Mar-2006
I have to say : they're always willing and pretty responsive at DevExpress to issues. Not as responsive as at SD 
....but they do at least their best !
Let's keep them busy....
DevExpress has responded, and I'm not a bit wiser... 
I just thought of another thing: paging. They likely will use Skip/Take for paging. However, skip for paging isn't supported by us, nor by some competitors of ours: we all use an extension method for paging. Linq to Sql often dies with using skip/take as it requires other elements to be in the query to work with skip/take (like order by, you can't always use joins etc. etc.).
Ok, I managed to implement grouping on constants. It required a different, special case codepath inside the groupby handler, but as this is an edge case, I think it's ok.
LinqMetaData metaData = new LinqMetaData(adapter);
var q = from c in metaData.Customer
where c.Country=="USA"
group c by 0 into cc
select cc.Count();
foreach(var v in q)
{
Assert.AreEqual(13, v);
}
Not sure if this works with the rest of the elements DevExpress tries to cram into the query, but at least grouping on constants works. THough I still would like to see them change this requirement, as it's not really helpful to them either: requiring edge-case queries to do simple things is IMHO not what they should try to achieve.
(attached).
Could someone with xtragrid 8.1 rc try this one?
SOmething else fails, 22 tests fail, looking into it.
(edit) oh how embarrasing I changed the internals into publics in LinqUtils, but this made the methodinfo grabbing code for a method inside LinqUtils not working anymore.