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  • Filtering DBNull With LINQ

    - by Steven
    Why does the following query raise the error below for a row with a NULL value for barrel when I explicitly filter out those rows in the Where clause? Dim query = From row As dbDataSet.conformalRow In dbDataSet.Tables("conformal") _ Where Not IsDBNull(row.Cal) AndAlso tiCal_drop.Text = row.Cal _ AndAlso Not IsDBNull(row.Tran) AndAlso tiTrans_drop.Text = row.Tran _ AndAlso Not IsDBNull(row.barrel) _ Select row.barrel If query.Count() > 0 Then tiBarrel_txt.Text = query(0) Run-time exception thrown : System.Data.StrongTypingException - The value for column 'barrel' in table 'conformal' is DBNull. How should my query / condition be rewritten to work as I intended?

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  • Subsonic 3.0 Query limit with MySQL c#.net LinQ

    - by omegawkd
    Hello, a quick question which may or may not be easily answered. Currently, in order to return a limited result set of data to my calling reference using SubSonic I use a similar function as below: _DataSet = from CatSet in t2_aspnet_shopping_item_category.All() join CatProdAssignedLink in t2_aspnet_shopping_link_categoryproduct.All() on CatSet.CategoryID equals CatProdAssignedLink.CategoryID join ProdSet in t2_aspnet_shopping_item_product.All() on CatProdAssignedLink.ProductID equals ProdSet.ProductID where ProdSet.ProductID == __ProductID orderby CatProdAssignedLink.LinkID ascending select CatSet; and select the first item from the data set. Is there a way to limit the lookup initially to a certain amount of rows? I'm using MySQL as the base database.

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  • Linq guru - filtering related entities...

    - by vdh_ant
    My table structure is as follows: Person 1-M PesonAddress Person 1-M PesonPhone Person 1-M PesonEmail Person 1-M Contract Contract M-M Program Contract M-1 Organization At the end of this query I need a populated object graph where each person has their: PesonAddress's PesonPhone's PesonEmail's PesonPhone's Contract's - and this has its respective Program's Now I had the following query and I thought that it was working great, but it has a couple of problems: from people in ctx.People.Include("PersonAddress") .Include("PersonLandline") .Include("PersonMobile") .Include("PersonEmail") .Include("Contract") .Include("Contract.Program") where people.Contract.Any( contract => (param.OrganizationId == contract.OrganizationId) && contract.Program.Any( contractProgram => (param.ProgramId == contractProgram.ProgramId))) select people; The problem is that it filters the person to the criteria but not the Contracts or the Contract's Programs. It brings back all Contracts that each person has not just the ones that have an OrganizationId of x and the same goes for each of those Contract's Programs respectively. What I want is only the people that have at least one contract with an OrgId of x with and where that contract has a Program with the Id of y... and for the object graph that is returned to have only the contracts that match and programs within that contract that match. I kinda understand why its not working, but I don't know how to change it so it is working... This is my attempt thus far: from people in ctx.People.Include("PersonAddress") .Include("PersonLandline") .Include("PersonMobile") .Include("PersonEmail") .Include("Contract") .Include("Contract.Program") let currentContracts = from contract in people.Contract where (param.OrganizationId == contract.OrganizationId) select contract let currentContractPrograms = from contractProgram in currentContracts let temp = from x in contractProgram.Program where (param.ProgramId == contractProgram.ProgramId) select x where temp.Any() select temp where currentContracts.Any() && currentContractPrograms.Any() select new Person { PersonId = people.PersonId, FirstName = people.FirstName, ..., ...., MiddleName = people.MiddleName, Surname = people.Surname, ..., ...., Gender = people.Gender, DateOfBirth = people.DateOfBirth, ..., ...., Contract = currentContracts, ... }; //This doesn't work But this has several problems (where the Person type is an EF object): I am left to do the mapping by myself, which in this case there is quite a lot to map When ever I try to map a list to a property (i.e. Scholarship = currentScholarships) it says I can't because IEnumerable is trying to be cast to EntityCollection Include doesn't work Hence how do I get this to work. Keeping in mind that I am trying to do this as a compiled query so I think that means anonymous types are out.

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  • Cannot add table to context - LINQ-To-SQL

    - by Oskar Kjellin
    Hey, I'd be happy to give you more info if you need, just ask for it. I have in my database a table of articles, a table of tags and a link table. The article table has values like Id, Subject etc etc, the tags only have Id and Tag. The link has TagId and ArticleId. The problem is that when I drag drop the link-table nothing happens! This all worked before I decided to rename my column in the tables from "ID" to "Id" to correct spelling. Thanks in advance!

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  • LINQ Joining in c# with multiple conditions

    - by Ratheesh
    Hi Following query is not working is there any problem with it? var possibleSegments = from epl in eventPotentialLegs join sd in segmentDurations on new { epl.ITARequestID, epl.ITASliceNumber, epl.DepartAirportAfter, epl.AirportId_Origin, epl.AirportId_Destination } equals new { sd.ITARequestId, sd.SliceIndex, sd.OriginAirport, sd.DestinationAirport } where epl.DepartAirportAfter > sd.UTCDepartureTime and epl.ArriveAirportBy > sd.UTCArrivalTime select new PossibleSegments{ ArrivalTime = sd.arrivalTime };

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  • Refreshing BindingSource after insert (Linq To SQL)

    - by Armagan
    I have a grid bound to a BindingSource which is bound to DataContext table, like this: myBindingSource.DataSource = myDataContext.MyTable; myGrid.DataSource = myBindingSource; I couldn't refresh BindingSource after insert. This didn't work: myDataContext.Refresh(RefreshMode.OverwriteCurrentValues, myBindingSource); myBindingSource.ResetBinding(false); Neither this: myDataContext.Refresh(RefreshMode.OverwriteCurrentValues, myDataContext.MyTable); myBindingSource.ResetBinding(false); What should I do?

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  • Referencing a Newly inserted Row's seeded PK in C# Linq

    - by Laurence Burke
    I want to use the primary key that was just created on the dc.submitchanges() to create a new EmployeeAddress row that references the employee to the address. protected void btnAdd_Click(object sender, EventArgs e) { if (txtZip.Text != "" && txtAdd1.Text != "" && txtCity.Text != "") { TestDataClassDataContext dc = new TestDataClassDataContext(); Address addr = new Address() { AddressLine1 = txtAdd1.Text, AddressLine2 = txtAdd2.Text, City = txtCity.Text, PostalCode = txtZip.Text, StateProvinceID = Convert.ToInt32(ddlState.SelectedValue) }; dc.Addresses.InsertOnSubmit(addr); lblSuccess.Visible = true; lblErrMsg.Visible = false; dc.SubmitChanges(); // // TODO: insert new row in EmployeeAddress to reference CurEmp to newly created address // SetAddrList(); } else { lblErrMsg.Text = "Invalid Input"; lblErrMsg.Visible = true; } } protected void SetAddrList() { TestDataClassDataContext dc = new TestDataClassDataContext(); dc.ObjectTrackingEnabled = false; var addList = from addr in dc.Addresses from eaddr in dc.EmployeeAddresses where eaddr.EmployeeID == _curEmpID && addr.AddressID == eaddr.AddressID select new { AddValue = addr.AddressID, AddText = addr.AddressID, }; ddlAddList.DataSource = addList; ddlAddList.DataValueField = "AddValue"; ddlAddList.DataTextField = "AddText"; ddlAddList.DataBind(); ddlAddList.Items.Add(new ListItem("<Add Address>", "-1")); }

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  • Linq query with aggregate function OrderBy

    - by Billy Logan
    Hello everyone, I have the following LinqToEntities query, but am unsure of where or how to add the orderby clause: var results = from d in db.TBLDESIGNER join s in db.TBLDESIGN on d.ID equals s.TBLDESIGNER.ID where s.COMPLETED && d.ACTIVE let value = new { s, d} let key = new { d.ID, d.FIRST_NAME, d.LAST_NAME } group value by key into g orderby g.Key.FIRST_NAME ascending, g.Key.LAST_NAME ascending select new { ID = g.Key.ID, FirstName = g.Key.FIRST_NAME, LastName = g.Key.LAST_NAME, Count = g.Count() }; This should be sorted by First_Name ascending and then Last_Name ascending. I have tried adding ordering but It has had no effect on the result set. Could someone please provide an example of where the orderby would go assuming the query above. Thanks, Billy

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  • VB.NET add an element to the XML document with LINQ to XML

    - by Bayonian
    Hi, I'm adding an element to existing XML doc with the following code: Dim theXMLSource As String = Server.MapPath("~/Demo/") & "LabDemo.xml" Dim nodeElement As XElement Dim attrAndValue As XElement = _ <LabService> <ServiceType> <%= txtServiceType.Text.Trim %> </ServiceType> <Level> <%= txtLevel.Text.Trim %> </Level> </LabService> nodeElement.Add(New XElement(attrAndValue)) nodeElement.Save(theXMLSource) It makes error like this: System.NullReferenceException: Object reference not set to an instance of an object. Object reference not set to an instance of an object. Error line: nodeElement.Add(New XElement(attrAndValue)) I debugged it but I couldn't get the error yet. Can you show what the problem is? Thank you

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  • LINQ to SQL: To Attach or Not To Attach

    - by bradhe
    So I'm have a really hard time figuring out when I should be attaching to an object and when I shouldn't be attaching to an object. First thing's first, here is a small diagram of my (very simplified) object model. Edit: Okay, apparently I'm not allowed to post images...here you go: http://i.imgur.com/2ROFI.png In my DAL I create a new DataContext every time I do a data-related operation. Say, for instance, I want to save a new user. In my business layer I create a new user. var user = new User(); user.FirstName = "Bob"; user.LastName = "Smith"; user.Username = "bob.smith"; user.Password = StringUtilities.EncodePassword("MyPassword123"); user.Organization = someOrganization; // Assume that someOrganization was loaded and it's data context has been garbage collected. Now I want to go save this user. var userRepository = new RepositoryFactory.GetRepository<UserRepository>(); userRepository.Save(user); Neato! Here is my save logic: public void Save(User user) { if (!DataContext.Users.Contains(user)) { user.Id = Guid.NewGuid(); user.CreatedDate = DateTime.Now; user.Disabled = false; //DataContext.Organizations.Attach(user.Organization); DataContext.Users.InsertOnSubmit(user); } else { DataContext.Users.Attach(user); } DataContext.SubmitChanges(); // Finished here as well. user.Detach(); } So, here we are. You'll notice that I comment out the bit where the DataContext attachs to the organization. If I attach to the organization I get the following exception: NotSupportedException: An attempt has been made to Attach or Add an entity that is not new, perhaps having been loaded from another DataContext. This is not supported. Hmm, that doesn't work. Let me try it without attaching (i.e. comment out that line about attaching to the organization). DuplicateKeyException: Cannot add an entity with a key that is already in use. WHAAAAT? I can only assume this is trying to insert a new organization which is obviously false. So, what's the deal guys? What should I do? What is the proper approach? It seems like L2S makes this quite a bit harder than it should be...

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  • Upper extension method in linq to NHibernate

    - by Daniel
    I would like to use the Upper extension method which is declared on the IDbMethods interface against Sql Server 2008. I understand that this will translate to UPPER() on sql server. However I can not figure out how to get an implementation of IDbMethods so that I can use the extension method.

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  • dataset to List<T>using linq

    - by bharat
    I have the dataset and I want to convert the dataset into List<T> T - type object How do I do it my dataset? It has 10 columns, with all 10 properties my object has and it's returning over 15000 rows. I want to return that dataset into List<obj> and loop it how do I do that?

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  • Need Simple way to access XML in VB.Net - Pain with Linq-to-Xml

    - by aiart
    Dim myXDoc As XDocument = _ I want to access this in a simple way in VB.Net - Like: Dim Integer SizeXStr = CInt(MyZDoc.Cameras(1).Camera_Desc.@SizeX) ' where (1) is an index Why isn't this implemented in VB.Net? Better yet, type the values with a Schema and eliminate the conversion. Is this so hard? How do I access, in a simple way, data in XML - this would be VERY VERY useful! I have been using Query to try to get the values - when I use MsgBox() to display results, they display, but my main Windows Form is Trashed - changed colors, etc. The system has Bugs. Instead, I have to create an elaborate structure of arrays of objects and read the XML line-by-line and do the same for saving - this is the dark ages. Art

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  • XmlDocument from LINQ to XML query

    - by Ben
    I am loading an XML document into an XDocument object, doing a query and then returning the data through a web service as an XmlDocument object. The code below works fine, but it just seems a bit smelly. Is there a cleaner way to take the results of the query and convert back to an XDocument or XmlDocument? XDocument xd = XDocument.Load(Server.MapPath(accountsXml)); var accounts = from x in xd.Descendants("AccountsData") where userAccounts.Contains(x.Element("ACCOUNT_REFERENCE").Value) select x; XDocument xd2 = new XDocument( new XDeclaration("1.0", "UTF-8", "yes"), new XElement("Accounts") ); foreach (var account in accounts) xd2.Element("Accounts").Add(account); return xd2.ToXmlDocument();

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  • C# LINQ to SQL Except Operator

    - by kb
    Hi i have a list of event Ids that i want to be excluded from my select statement, but no sure how to implement this: this is what stores my list of event Ids List<int> ExcludedEvents; and this is my select statement (from an XML feed) var allEvents = from eventsList in xmlDoc.Elements("shows").Elements("Show") select new EventFeed() { EventName = eventsList.Attribute("Name").Value, EventSummary = eventsList.Attribute("ShortDesc").Value, EventDetails = eventsList.Attribute("LongDesc").Value, EventShowCode = eventsList.Attribute("Code").Value }; i want to select all events except for the events that have their eventId matching the EventShowCode value i have looked at the except operator, but not sure how to implement it thanks

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  • How to select all the attributes that contain certain String in an XML Document using LINQ

    - by jaircazarin
    Similar to XPath: How to match attributes that contain a certain string but without using XPath. Is it possible? <c BarFoo="val1"> <d Foo="val2" someAttribute=""> <e FooBar="val3" /> </d> </c> Basically I want to select all the attribute values in the document that their attribute name contains "Foo", so it should return the values of "BarFoo", "FooBar", "Foo" (va1, val2, val3)

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  • Linq to SQL Web Service XML

    - by Bryan
    I built a .NET web service connecting to an MSSQL database. There is a web service call GetAllQuestions() that will not change. I saved the result of GetAllQuestions to GetAllQuestions.xml in the local application folder and set it to content. Normally I would get the result of the web service like this: var myService = new SATService(); var serviceQuestions = myService.GetAllQuestions(); I want to try something like: var serviceQuestions = File.Open("GetAllQuestions.xml"); Any suggestions are much appreciated!

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  • Linq-to-sql orderby thenby

    - by Curtis White
    I'm using the following query syntax from table where where orderby orderby Where the first orderby is a date and second orderby is a date. I would assume this would work like orderby thenby but appears to be doing something else. 1 How can I do an orderby thenby using the above syntax without using extension syntax. (Got it) 2 And what does the orderby, orderby do?

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  • LINQ to XML Cloning

    - by Sir Psycho
    Can anyone explain why the original address XElement street node changes? It looks like customer1 holds a reference to the address XElement but customer2 and customer3 have taken copies. Why did the original address change? (LINQPad example) var address = new XElement ("address", new XElement ("street", "Lawley St"), new XElement ("town", "North Beach") ); var customer1 = new XElement ("customer1", address); var customer2 = new XElement ("customer2", address); var customer3 = new XElement ("customer3", address); customer1.Element ("address").Element ("street").Value = "Another St"; Console.WriteLine (customer2.Element ("address").Element ("street").Value); Console.WriteLine (); address.Dump(); Console.WriteLine (); customer1.Dump(); Console.WriteLine (); customer2.Dump(); Console.WriteLine (); customer3.Dump(); OUTPUT Lawley St <address> <street>Another St</street> <town>North Beach</town> </address> <customer1> <address> <street>Another St</street> <town>North Beach</town> </address> </customer1> <customer2> <address> <street>Lawley St</street> <town>North Beach</town> </address> </customer2> <customer3> <address> <street>Lawley St</street> <town>North Beach</town> </address> </customer3>

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  • XML Reader or Linq to XML

    - by Nasser Hajloo
    I have a 150MB XML file which used asDB in my project. Currently I'm using XMLReader to read content from it. I want to know it is better to use XMLReader or LinqToXML for this scenario. Note that I'm searching for an item in this xmland display search result, soitcan be take along or just a moment.

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  • Linq help using "Contains"

    - by Kettenbach
    Good Morning All, I'm trying to use "Contains" to see if an object is within the collection. When I break I can see that the object is indeed part of the collection however "Contains" seems to be returning false indicating the item is not in the collection. Any idea what I'm doing wrong? if(HttpContext.Current.Session["AutoPayTypes"] != null) { var autopays = HttpContext.Current.Session["AutoPayTypes"] as List<PaymentTypeInfo>; char? coverageProductLine = null; if(entityProps.ContainsKey("CoverageProductLine")) { coverageProductLine = (char?)entityProps["CoverageProductLine"]; } var paymentTypeInfoRepository = new PaymentTypeInfoRepository(); var payType = paymentTypeInfoRepository.GetPaymentTypeInfo(paymentAdd.PayType, coverageProductLine); if (autopays != null && payType != null) paymentAdd.DaysPaid = autopays.Contains(payType) ? null : paymentAdd.DaysPaid; } If the object is not in the collection the "DaysPaid" needs to be null. Any ideas? Thanks, ~ck in San Diego

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  • refactor LINQ TO SQL custom properties that instantiate datacontext

    - by Thiago Silva
    I am working on an existing ASP.NET MVC app that started small and has grown with time to require a good re-architecture and refactoring. One thing that I am struggling with is that we've got partial classes of the L2S entities so we could add some extra properties, but these props create a new data context and query the DB for a subset of data. This would be the equivalent to doing the following in SQL, which is not a very good way to write this query as oppsed to joins: SELECT tbl1.stuff, (SELECT nestedValue FROM tbl2 WHERE tbl2.Foo = tbl1.Bar), tbl1.moreStuff FROM tbl1 so in short here's what we've got in some of our partial entity classes: public partial class Ticket { public StatusUpdate LastStatusUpdate { get { //this static method call returns a new DataContext but needs to be refactored var ctx = OurDataContext.GetContext(); var su = Compiled_Query_GetLastUpdate(ctx, this.TicketId); return su; } } } We've got some functions that create a compiled query, but the issue is that we also have some DataLoadOptions defined in the DataContext, and because we instantiate a new datacontext for getting these nested property, we get an exception "Compiled Queries across DataContexts with different LoadOptions not supported" . The first DataContext is coming from a DataContextFactory that we implemented with the refactorings, but this second one is just hanging off the entity property getter. We're implementing the Repository pattern in the refactoring process, so we must stop doing stuff like the above. Does anyone know of a good way to address this issue?

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  • count on LINQ union

    - by brechtvhb
    I'm having this link statement: List<UserGroup> domains = UserRepository.Instance.UserIsAdminOf(currentUser.User_ID); query = (from doc in _db.Repository<Document>() join uug in _db.Repository<User_UserGroup>() on doc.DocumentFrom equals uug.User_ID where domains.Contains(uug.UserGroup) select doc) .Union(from doc in _db.Repository<Document>() join uug in _db.Repository<User_UserGroup>() on doc.DocumentTo equals uug.User_ID where domains.Contains(uug.UserGroup) select doc); Running this statement doesn't cause any problems. But when I want to count the resultset the query suddenly runs quite slow. totalRecords = query.Count(); The result of this query is : SELECT COUNT([t5].[DocumentID]) FROM ( SELECT [t4].[DocumentID], [t4].[DocumentFrom], [t4].[DocumentTo] FROM ( SELECT [t0].[DocumentID], [t0].[DocumentFrom], [t0].[DocumentTo FROM [dbo].[Document] AS [t0] INNER JOIN [dbo].[User_UserGroup] AS [t1] ON [t0].[DocumentFrom] = [t1].[User_ID] WHERE ([t1].[UserGroupID] = 2) OR ([t1].[UserGroupID] = 3) OR ([t1].[UserGroupID] = 6) UNION SELECT [t2].[DocumentID], [t2].[DocumentFrom], [t2].[DocumentTo] FROM [dbo].[Document] AS [t2] INNER JOIN [dbo].[User_UserGroup] AS [t3] ON [t2].[DocumentTo] = [t3].[User_ID] WHERE ([t3].[UserGroupID] = 2) OR ([t3].[UserGroupID] = 3) OR ([t3].[UserGroupID] = 6) ) AS [t4] ) AS [t5] Can anyone help me to improve the speed of the count query? Thanks in advance!

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