I see articles on using SPMetal to generate the .cs file that allows LINQ to work properly. The file I'm talking about inherits from the Microsoft.SharePoint.Linq.DataContext class. How can I use LINQ without recompiling on my production environment, since I would need to regenerate this file using SPMetal on my production environment? I suspect the answer is going to be "can't do it".
I guess I'll use a CAML query instead unless there is some easier way to use LINQ that I am missing.
If the objective is just to query lists using LINQ and you want to avoid such recompilations, do not use SPMetal.
LINQ can be directly used on SPListItemCollection
e.g.
var FindCustomer = from SPListItem Item in Customers.Items
where Item["Orders"] as int == 5
select Item;
//or select new{Title = Item["Title"]}
This does not have hard coded entities but is more flexible. And as long as your list column names remain same, code can be deployed on any environment even if other lists are changing.
Also you can choose to retrieve few chosen field's data instead of retrieving data of all the fields every time.
There is no problem I guess. Personally I have been using Linq for good amount of time. I never generated the cs specifically for production. Is your site different across environments?
Im not sure if I'm missing the point or not, but the DataContext object takes the URL as apart of the constructor, so you should retrieve the URL from config somewhere E.g. database
DataContext teamSite = new DataContext("http://MarketingServer/SalesTeam");
OR use the SPContext object, if your code has a SharePoint context. E.g. in a web part
DataContext teamSite = new DataContext(SPContext.Current.Web.Url);
Related
I've been refactoring an existing Umbraco project to use more performant querying when getting back document data as everything was previously being returned using LINQ. I have been using a combination of Umbraco's querying via XPaths and Examine.
I am currently stumped on trying to get child documents using the Umbraco.ContentAtXPath() method. What I would like to do is get child document based on a path I parse to the method. This is what I have currently:
IEnumerable<IPublishedContent> umbracoPages = Umbraco.ContentAtXPath("//* [#isDoc]/descendant::/About [#isDoc]");
Running this returns a "Object reference not set to an instance of an object." error and unable to see exactly where I'm going wrong (new to this form of querying in Umbraco).
Ideally, I'd like to enhance the querying to also carry out sorting using the non-LINQ approach, as demonstrated here.
Up until Umbraco 8, content was cached in an XML file, which made XPath perfect for querying content efficiently. In v8, however, the so called "NuCache" is not file based nor XML based, so the XPath query support is only there for ... well... Old times sake, I guess? Either way it's probably not going to be super efficient and (I'd advise) not something to "aim for". That said I of course don't know what you are changing from (Linq can be a lot of things) :-/
It certainly depends on how big your dataset is.
As Umbraco has moved away from the XML backed cache, you should look into Linq queries against your content models. Make sure you use ModelsBuilder to generate the models.
On a small dataset Linq will be much quicker than examine. On a large dataset Examine/Lucene will be much more steady on performance.
Querying NuCache is pretty fast in Umbraco 8, only beaten by an Examine search.
Assuming you're using Models Builder, and your About page is a child of Home page, you could use:
var homePage = (HomePage) Model.Root();
var aboutPage = homePage?.Children<AboutPage>().FirstOrDefault();
var umbracoPages = aboutPage.Children();
Where HomePage is your home page Document Type Alias and AboutPage is your About page Document Type alias.
In the following microsoft documentation: -
https://learn.microsoft.com/en-us/sql/ado/guide/appendixes/microsoft-data-shaping-service-for-ole-db-ado-service-provider?view=sql-server-2017
this feature is being removed and the suggestion is to use XML. Has anyone done this? I'm wondering what they mean, in terms of loading the structure of what MSDataShape is by using XML, or just to use XML objects?
TIA
I believe this is referring to the FOR XML clause of T-SQL, which performs much the same job as MSDataShape in that it returns hierarchically nested data.
Port your MSDataShape queries to FOR XML queries and change the client to parse the results instead of using the MSDataShape OLEDB provider.
At the client side, SAX or pull parsing would be the best fit to port code that previously used MSDataShape (which also had a move-through-the-records cursor based model).
This is my bit of code that is helpful. My MSDataShape code still works, therefore I propose using that to generate your XML as a template, then use that going forward to load them: -
Dim objShapeMaker As clsShapeMaker
Dim rsoTemp As ADODB.Recordset
Dim strXMLTemplate As String
' Template file
strXMLTemplate = "C:\Temp\Template_GI.xml"
' Create the MSDataShape and save it to XML
Set rsoTemp = objShapeMaker.CreateGI()
rsoTemp.Save strXMLTemplate, adPersistXML
' Now we have the XML in a file going forward, load it in my recordset
Set rsoTemp = New ADODB.Recordset
rsoTemp.Open strXMLTemplate, , , , adCmdFile
' Cleanup
Set rsoTemp = Nothing
Set objShapeMaker = Nothing
If you don't like the idea of generating XML template files to maintain, you could do this via .NET and expose it to COM to use in your VB6/VBA application as mentioned here.
I have made a .NET application that can generate these XML files from simple code lines should anyone want going forward that is similar to the blog listed, however it handles child recordsets with relationships.
EDIT 1: This works great if you have schema set ups without returning data. As far as I can tell, to populate these effectively, it's better to write code to load the structure first, and populate it after from seperate recordsets (which is slower!)
EDIT 2: This is the approach we are taking with a replacement in a .NET Interop. Initially looking at bringing XML from SQL and parsing that back as required. This could be bought back into a DataSet and that's parsed into the target recordset as well, but then the relationship between the tables in the result dataset needs to be set in code rather than the one place in T-SQL with XML output.
I am trying to list the view template’s properties so we can compare them with another old template.
For example what model elements are hidden or have overrides in a given template or which Revit links have been hidden or overridden in a given template.
View Template
(https://www.google.com/search?q=view+template+revit&rlz=1C1GGRV_enUS770US770&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjLndrd2cTbAhVESq0KHX1cAPwQ_AUICygC&biw=1536&bih=824#imgrc=Q0v-pV7Nxl4kfM:)
I’m looking to devise a View Template Compare tool and access to the owner and creator of them.
public void ApplyViewTemplateToActiveView()
{
Document doc = this.ActiveUIDocument.Document;
View viewTemplate = (from v in new FilteredElementCollector(doc)
.OfClass(typeof(View))
.Cast<View>()
where v.IsTemplate == true && v.Name == "MyViewTemplate"
select v)
.First();
using (Transaction t = new Transaction(doc,"Set View Template"))
{
t.Start();
doc.ActiveView.ViewTemplateId = viewTemplate.Id;
t.Commit();
}
}
With Revit API you can access with:
GetTemplateParameterIds Method / ViewTemplateId Property
The Revit API exposes almost all the ViewTemplate properties.
For instance this method returns all the Visibility/Graphic Overrides for a specific category:
https://apidocs.co/apps/revit/2019/ed267b82-56be-6e3b-0c6d-4de7df1ed312.htm
The only thing I couldn't get for a ViewTemplate are the "includes", but all the rest seems to be there.
Update:
The list or properties "not included" can be retrieved with GetNonControlledTemplateParameterIds().
Yes, and no.
Yes, I guess you can use Forge Model Derivative API to export RVT file and then build a dashboard around the View Templates data. That's assuming that View Templates data actually gets exported when the model is translated. That data is not attached to any geometry so I would not be surprised if it was skipped. The question here is why? This is like renting a 16-wheel truck to move a duffel bag across the street.
No, if your intention is to directly interact with the RVT model. Forge can view it, but to push anything back or request changes to the model, is not available yet. Then again, I am not even sure that the view template data is available via model derivative exports.
This brings me another alternative. Why not just collect the data using Revit API, the standard way and then push it out to a Database and build on top of that? There is no reason to employ Forge for any of that.
Thanks Jeremy, I had dig into your amazing website and also some solution that Konrad post in the Dynamo Forum about this. In Revit seems pretty achievable, you filter the View that is View Template and then extracts these properties, is it correct?.
I am wondering if someone can point me in the right direction with Forge.
Some amazing guys are developing a BQL https://www.retriever.works/.
BQL(Building Query Language) is a query language for buildings, similar to how SQL is a query language for databases. It is fast and flexible. BQL helps improve efficiency for QA/QC (quality assurance and quality control), and building data extraction without leaving Revit. I am also trying these and I would like to understand if there are some works where I could start with Forge next week about this.
My collegue helped me with starting programming in c# although I had no experience but I like it. All went well until I came across some problems we both can't fix. He uses SQL himself but started me up with LINQ.
To do a LINQ-query I use this object : _oDBConnection (in clsApplication.cs)
So when opening the programm this object is built. But it creates some problems:
When saving a new object (putting data into table), I cannot load those values with a query. I need to restart the programm.
When running 2 instances of the programm, one is not getting the latest values when changed in the other (but it is showing the new ones but not the changed ones!)
According to these problems I can only conclude that when I call clsApplication._oDBConnection.tblTAble a second time it is not relinking again to the db but is giving me the old db-states back.
This is the code he built:
public static DBReservationDataContext _oDBConnection;
private static frmMain _fMain;
public clsApplication()
{
Thread.CurrentThread.Name = "main";
clsErrorLog.ErrorLocation = "C:\\Software\\ErrorLog";
clsErrorLog.setPassword("*****");
clsErrorLog.LockApplication += new clsErrorLog.dLockApplication(lockApplication);
_oDBConnection = new DBReservationDataContext();
_fMain = new frmMain();
_fMain.Show();
}
What can I do to fix this problem?
Example:
although present in the database, it crashes on this query because the entity with id == iID is not found. But the iID is correct and it does exist in the database. The query will work after closing and restarting the programm. Then the clsApplication is called again.
public clsReservationDetail(int iID)
:this()
{
_oReservationDetail = (from oReservationDetailQuery in clsApplication._oDBConnection.tblReservationDetails
where oReservationDetailQuery.ID == iID
select oReservationDetailQuery).First();
}
thx in advance
Your data context will have a Refresh method which will clear any cached results, and should allow your query to complete with no problems
The static keyword makes it so that you have one reference per AppDomain. That is the wrong way to use DataContext instances.
Each instance of DataContext tracks the objects it has seen. This is for consistency. If you get a Customer instance with CustomerID = 4 from one query, you should get the same Customer instance from another query that returns the CustomerID = 4 record.
If you want to see the changes in the database, you must
1) Tell the datacontext to stop tracking changes. This must be done before the first query and makes the datacontext instance unable to SubmitChanges (since it can't track them anymore).
OR
2) Tell the datacontext to Refresh each instance you suspect has changed. If you do that, you should specify how resolve the conflict between your local changes and the remote changes - the simplest way of resolving this conflict is to have no local changes.
OR
3) (The right way) Make a new DataContext instance and load the record with that!
Also note: Since DataContext implements IDisposable, you are required to call Dispose when you are done with each instance even when exceptions occur. The using block is a good way to get that to happen.
I have been trying to use dynamic LINQ to Entity in my application for specifying the OrderBy attribute at runtime. However when using the code as described in the majority of documentation:
var query = context.Customer.OrderBy("Name");
I received the following exception:
System.Data.EntitySqlException: 'Name' could not be resolved in the current scope or context. Make sure that all referenced variables are in scope, that required schemas are loaded, and that namespaces are referenced correctly.
After much searching I found this MSDN page:
http://msdn.microsoft.com/en-us/library/bb358828.aspx
Which included the following code example:
ObjectQuery<Product> productQuery2 = productQuery1.OrderBy("it.ProductID");
This prompted me to change my code to the following:
var query = context.Customer.OrderBy("it.Name");
After this the code works perfectly. Would anyone be able to confirm that this is indeed the correct way to get OrderBy working with LINQ to Entity? I can’t believe that the framework would have been implemented in this way, perhaps I have overlooked something?
Thanks, Matt
The it.Name syntax is ESQL and is indeed specific to the EF. There are good reasons to use this sometimes (e.g., collation specifiers), but it's not what I normally do.
Usually I use standard LINQ expressions:
var query = context.Customer.OrderBy(p => p.Name);
You can also use System.Linq.Dynamic, if you download it from Code Gallery, and then your original query:
var query = context.Customer.OrderBy("Name");
...will work.
No nice way, so far
My answer to this question was to create a stored procedure which has parameter to control sorting.