There are some pitfalls when retrieving CRM entities with LinqtoCRM and trying to update them through the CRM web service. The most intuitive (but wrong) approach would be this:
var res = from c in p.Linq()
select c;
foreach (var con in res)
{
con.address1_line1 = "foo";
service.Update(con);
}
This fails unfortunately. I think someone at Netcompany (my former employer) worked out why this was at some point, but I’ve forgotten.
Instead what you want to do it is new up new entities yourself while setting the relevant id attribute, and then updating the attributes you want to change:
var res = from c in p.Linq()
select new contact() { contactid = c.contactid };
foreach (var con in res)
{
con.address1_line1 = "foo";
service.Update(con);
}
A few days, a former collegue alerted me to xRM LINQ, a new commercial query provider for Microsoft CRM. I’ve downloaded the trial, of course, and it looks pretty good. xRM LINQ decided not to use usual web service classes and instead provide their own class generator/entity mapper (LinqtoCRM has one too, but only for generating many-to-many classes). This means you can’t mix and match Linq with traditional web service calls, and they had to implement their own create/update functionality. It’s a less gradual and more comprehensive approach than LinqtoCRM but it may give a smoother experience for the programmer. At any rate, I welcome xRM LINQ onto the CRM query provider stage and wish them the best of luck :-).
A less welcome addition is a company called Softpedia, a Romanian outfit. I won’t link to them, to avoid giving them any more Google Juice, but you can find them by googling LinqtoCRM. They seem to be screen-scraping CodePlex and similar sites for projects with permissive licenses and then put up copy-cat pages with downloads for these project on their own site. While not illegal, it’s not very useful for project owners or users either. They’ve been caught inflating their Wikipedia article and many user report trojans and similar on siteadvisor (to be fair, this seems to happen for other popular download sites too).
In other news, a new version of LinqtoCRM is out. It fixes some bugs that have surfaced over the last few months. I’ve also reorganised the wiki, hopefully making it easier for people to find what they’re looking for.
I’ve just recorded a web cast demontrating joins with LinqtoCRM. The piece de resistance is a join across a many-to-many relationship with the intermediary class generated by CRMMetal:
var res = from u in p.Linq()
join sr in p.Linq() on u.systemuserid.Value equals sr.systemuserid.Value
join r in p.Linq() on sr.roleid.Value equals r.roleid.Value
select new { u.fullname, r.name };
The equivalent example query in the CRM SDK is around forty lines, compared to four for LinqtoCRM. Watch the web cast here.