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  • using linq to sql

    - by mazhar
    Well I am new to this orm stuff. We have to create a large project . I read about linq to sql . will it be appropiate to use it in the project of high risk . i found no problem with it personally but the thing is that there will be no going back once started.So i need some feedback from the orm gurus here at the msdn.Will entity framework will be better?( I am in doubt about link to sql because I have read and heard negative feedback here and there) I will be using mvc2 as the framework. So please give the feedback about linq to sql in this regard. q2) Also I am a fan of stored procedure as they are precomputed and fasten up the thing and I have never worked without them.I know that linq to sql support stored procedures but will it be feasible to give up stored procedure seeing the beautiful data access layer generated with little effort as we are also in a need of rapid development. q3) If some changes to some fields required in the database in Link to Sql how will the changes be accommodated in the data access layer.

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  • using linq to sql

    - by user324831
    Well I am new to this orm stuff. We have to create a large project . I read about linq to sql . will it be appropiate to use it in the project of high risk . i found no problem with it personally but the thing is that there will be no going back once started.So i need some feedback from the orm gurus here at the msdn.Will entity framework will be better?( I am in doubt about link to sql because I have read and heard negative feedback here and there) I will be using mvc2 as the framework. So please give the feedback about linq to sql in this regard. q2) Also I am a fan of stored procedure as they are precomputed and fasten up the thing and I have never worked without them.I know that linq to sql support stored procedures but will it be feasible to give up stored procedure seeing the beautiful data access layer generated with little effort as we are also in a need of rapid development. q3) If some changes to some fields required in the database in Link to Sql how will the changes be accommodated in the data access layer.

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  • Convert SQL to LINQ in MVC3 with Ninject

    - by Jeff
    I'm using MVC3 and still learning LINQ. I'm having some trouble trying to convert a query to LINQ to Entities. I want to return an employee object. SELECT E.EmployeeID, E.FirstName, E.LastName, MAX(EO.EmployeeOperationDate) AS "Last Operation" FROM Employees E INNER JOIN EmployeeStatus ES ON E.EmployeeID = ES.EmployeeID INNER JOIN EmployeeOperations EO ON ES.EmployeeStatusID = EO.EmployeeStatusID INNER JOIN Teams T ON T.TeamID = ES.TeamID WHERE T.TeamName = 'MyTeam' GROUP BY E.EmployeeID, E.FirstName, E.LastName ORDER BY E.FirstName, E.LastName What I have is a few tables, but I need to get only the newest status based on the EmployeeOpertionDate. This seems to work fine in SQL. I'm also using Ninject and set my query to return Ienumerable. I played around with the group by option but it then returns IGroupable. Any guidance on converting and returning the property object type would be appreciated. Edit: I started writing this out in LINQ but I'm not sure how to properly return the correct type or cast this. public IQueryable<Employee> GetEmployeesByTeam(int teamID) { var q = from E in context.Employees join ES in context.EmployeeStatuses on E.EmployeeID equals ES.EmployeeID join EO in context.EmployeeOperations on ES.EmployeeStatusID equals EO.EmployeeStatusID join T in context.Teams on ES.TeamID equals T.TeamID where T.TeamName == "MyTeam" group E by E.EmployeeID into G select G; return q; } Edit2: This seems to work for me public IQueryable<Employee> GetEmployeesByTeam(int teamID) { var q = from E in context.Employees join ES in context.EmployeeStatuses on E.EmployeeID equals ES.EmployeeID join EO in context.EmployeeOperations.OrderByDescending(eo => eo.EmployeeOperationDate) on ES.EmployeeStatusID equals EO.EmployeeStatusID join T in context.Teams on ES.TeamID equals T.TeamID where T.TeamID == teamID group E by E.EmployeeID into G select G.FirstOrDefault(); return q; }

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  • Creating a Linq->HQL provider

    - by Mike Q
    Hi all, I have a client application that connects to a server. The server uses hibernate for persistence and querying so it has a set of annotated hibernate objects for persistence. The client sends HQL queries to the server and gets responses back. The client has an auto-generated set of objects that match the server hibernate objects for query results and basic persistence. I would like to support using Linq to query as well as Hql as it makes the queries typesafe and quicker to build (no more typos in HQL string queries). I've looked around at the following but I can't see how to get them to fit with what I have. NHibernate's Linq provider - requires using NHibernate ISession and ISessionFactory, which I don't have LinqExtender - requires a lot of annotations on the objects and extending a base type, too invasive What I really want is something that will generate give me a nice easy to process structure to build the HQL queries from. I've read most of a 15 page article written by one of the C# developers on how to create custom providers and it's pretty fraught, mainly because of the complexity of the expression tree. Can anyone suggest an approach for implementing Linq - HQL translation? Perhaps a library that will the cleanup of the expression tree into something more SQL/HQLish. I would like to support select/from/where/group by/order by/joins. Not too worried about subqueries.

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  • "Most popular" GROUP BY in LINQ?

    - by tags2k
    Assuming a table of tags like the stackoverflow question tags: TagID (bigint), QuestionID (bigint), Tag (varchar) What is the most efficient way to get the 25 most used tags using LINQ? In SQL, a simple GROUP BY will do: SELECT Tag, COUNT(Tag) FROM Tags GROUP BY Tag I've written some LINQ that works: var groups = from t in DataContext.Tags group t by t.Tag into g select new { Tag = g.Key, Frequency = g.Count() }; return groups.OrderByDescending(g => g.Frequency).Take(25); Like, really? Isn't this mega-verbose? The sad thing is that I'm doing this to save a massive number of queries, as my Tag objects already contain a Frequency property that would otherwise need to check back with the database for every Tag if I actually used the property. So I then parse these anonymous types back into Tag objects: groups.OrderByDescending(g => g.Frequency).Take(25).ToList().ForEach(t => tags.Add(new Tag() { Tag = t.Tag, Frequency = t.Frequency })); I'm a LINQ newbie, and this doesn't seem right. Please show me how it's really done.

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  • LINQ query to find if items in a list are contained in another list

    - by cjohns
    I have the following code: List<string> test1 = new List<string> { "@bob.com", "@tom.com" }; List<string> test2 = new List<string> { "[email protected]", "[email protected]" }; I need to remove anyone in test2 that has @bob.com or @tom.com. What I have tried is this: bool bContained1 = test1.Contains(test2); bool bContained2 = test2.Contains(test1); bContained1 = false but bContained2 = true. I would prefer not to loop through each list but instead use a Linq query to retrieve the data. bContained1 is the same condition for the Linq query that I have created below: List<string> test3 = test1.Where(w => !test2.Contains(w)).ToList(); The query above works on an exact match but not partial matches. I have looked at other queries but I can find a close comparison to this with Linq. Any ideas or anywhere you can point me to would be a great help.

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  • WPF & Linq To SQL binding ComboBox to foreign key

    - by ZeroDelta
    I'm having trouble binding a ComboBox to a foreign key in WPF using Linq To SQL. It works fine when displaying records, but if I change the selection on the ComboBox, that change does not seem to affect the property to which it is bound. My SQL Server Compact file has three tables: Players (PK is PlayerID), Events (PK is EventID), and Matches (PK is MatchID). Matches has FKs for the the other two, so that a match is associated with a player and an event. My window for editing a match uses a ComboBox to select the Event, and the ItemsSource is set to the result of a LINQ query to pull all of the Events. And of course the user should be able to select the Event based on EventName, not EventID. Here's the XAML: <ComboBox x:Name="cboEvent" DisplayMemberPath="EventName" SelectedValuePath="EventID" SelectedValue="{Binding Path=EventID, UpdateSourceTrigger=PropertyChanged}" /> And some code-behind from the Loaded event handler: var evt = from ev in db.Events orderby ev.EventName select ev; cboEvent.ItemsSource = evt.ToList(); var mtch = from m in db.Matches where m.PlayerID == ((Player)playerView.CurrentItem).PlayerID select m; matchView = (CollectionView)CollectionViewSource.GetDefaultView(mtch); this.DataContext = matchView; When displaying matches, this works fine--I can navigate from one match to the next and the EventName is shown correctly. However, if I select a new Event via this ComboBox, the CurrentItem of the CollectionView doesn't seem to change. I feel like I'm missing something stupid! Note: the Player is selected via a ListBox, and that selection filters the matches displayed--this seems to be working fine, so I didn't include that code. That is the reason for the "PlayerID" reference in the LINQ query

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  • Slow T-SQL query, convert to LINQ to Object

    - by yimbot
    I have a T-SQL query which populates a DataSet from an MSSQL database. string qry = "SELECT * FROM EvnLog AS E WHERE TimeDate = (SELECT MAX(TimeDate) From EvnLog WHERE Code = E.Code) AND (Event = 8) AND (TimeDate BETWEEN '" + Start + "' AND '" + Finish + "')" The database is quite large and being the type of nested query it is, the Data Adapter can take a number of minutes to fill the DataSet. I have extended the DataAdapter's timeout value to 480 seconds to combat it, but the client still complains about slow performance and occassional timeouts. To combat this, I was considering executing a simpler query (ie. just taking the date range) and then populating a Generic List which I could then execute a Linq query against. The simple query executes very quickly which is great. However, I cannot seem to build a Linq query which generates the same results as the T-SQL query above. Is this the best solution to this problem? Can anyone provide tips on rewriting the above T-SQL into Linq? I have also considered using a DataView, but cannot seem to get the results from that either.

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  • LINQ to SQL Converter

    - by user609511
    How can I convert My LINQ to SQL ? i have this LINQ statement: int LimCol = Convert.ToInt32(LimitColis); result = oListTUP .GroupBy(x => new { x.Item1, x.Item2, x.Item3, x.Item4, x.Item5 }) .Select(g => new { Key = g.Key, Sum = g.Sum(x => x.Item6), Poids = g.Sum(x => x.Item7), }) .Select(p => new { Key = p.Key, Items = Enumerable.Repeat(LimCol, p.Sum / LimCol).Concat(Enumerable.Repeat(p.Sum % LimCol, p.Sum % LimCol > 0 ? 1 : 0)), CalculPoids = p.Poids / Enumerable.Repeat(LimCol, p.Sum / LimCol).Concat(Enumerable.Repeat(p.Sum % LimCol, p.Sum % LimCol > 0 ? 1 : 0)).Count() }) .SelectMany(p => p.Items.Select(i => Tuple.Create(p.Key.Item1, p.Key.Item2, p.Key.Item3, p.Key.Item4, p.Key.Item5, i, p.CalculPoids))) .ToList(); } It works well, but somehow want to push it and it become too complicated, so I want to convert it into Pure SQL. I have tried SQL Profiler and LinqPad, but neither shows me the SQL. How can I see the SQL code from My LINQ ? Thank you in advance.

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  • Map inheritance from generic class in Linq To SQL

    - by Ksenia Mukhortova
    Hi everyone, I'm trying to map my inheritance hierarchy to DB using Linq to SQL: Inheritance is like this, classes are POCO, without any LINQ to SQL attributes: public interface IStage { ... } public abstract class SimpleStage<T> : IStage where T : Process { ... } public class ConcreteStage : SimpleStage<ConcreteProcess> { ... } Here is the mapping: <Database Name="NNN" xmlns="http://schemas.microsoft.com/linqtosql/mapping/2007"> <Table Name="dbo.Stage" Member="Stage"> <Type Name="BusinessLogic.Domain.IStage"> <Column Name="ID" Member="ID" DbType="Int NOT NULL IDENTITY" IsPrimaryKey="true" IsDbGenerated="true" AutoSync="OnInsert" /> <Column Name="StageType" Member="StageType" IsDiscriminator="true" /> <Type Name="BusinessLogic.Domain.SimpleStage" IsInheritanceDefault="true"> <Type Name="BusinessLogic.Domain.ConcreteStage" IsInheritanceDefault="true" InheritanceCode="1"/> </Type> </Type> </Table> </Database> In the runtime I get error: System.InvalidOperationException was unhandled Message="Mapping Problem: Cannot find runtime type for type mapping 'BusinessLogic.Domain.SimpleStage'." Neither specifying SimpleStage, nor SimpleStage<T> in mapping file helps - runtime keeps producing different types of errors. DC is created like this: StreamReader sr = new StreamReader(@"MappingFile.map"); XmlMappingSource mapping = XmlMappingSource.FromStream(sr.BaseStream); DataContext dc = new DataContext(@"connection string", mapping); If Linq to SQL doesn't support this, could you, please, advise some other ORM, which does. Thanks in advance, Regards! Ksenia

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  • fastest way to check to see if a certain index in a linq statement is null

    - by tehdoommarine
    Basic Details I have a linq statement that grabs some records from a database and puts them in a System.Linq.Enumerable: var someRecords = someRepoAttachedToDatabase.Where(p=>true); Suppose this grabs tons (25k+) of records, and i need to perform operations on all of them. to speed things up, I have to decided to use paging and perform the operations needed in blocks of 100 instead of all of the records at the same time. The Question The line in question is the line where I count the number of records in the subset to see if we are on the last page; if the number of records in subset is less than the size of paging - then that means there are no more records left. What I would like to know is what is the fastest way to do this? Code in Question int pageSize = 100; bool moreData = true; int currentPage = 1; while (moreData) { var subsetOfRecords = someRecords.Skip((currentPage - 1) * pageSize).Take(pageSize); //this is also a System.Linq.Enumerable if (subsetOfRecords.Count() < pageSize){ moreData = false;} //line in question //do stuff to records in subset currentPage++; } Things I Have Considered subsetOfRecords.Count() < pageSize subsetOfRecords.ElementAt(pageSize - 1) == null (causes out of bounds exception - can catch exception and set moreData to false there) Converting subsetOfRecords to an array (converting someRecords to an array will not work due to the way subsetOfRecords is declared - but I am open to changing it) I'm sure there are plenty of other ideas that I have missed.

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  • C# Linq Select Problem in Method Chain.

    - by Gnought
    Note that the _src inherit IQueryable<U> and V inherit new(); I wrote the following statement, there is no syntax error. IQueryable<V> a = from s in _src where (s.Right - 1 == s.Left) select new V(); But if i re-wrote it as follows, the Visual Studio editor complains an error in the "Select" IQueryable<V> d = _src.Where(s => s.Right - 1 == s.Left).Select(s=> new V()); The Error is: The type arguments cannot be inferred from the usage. Try specifying the type arguments explicitly. Candidates are: System.Collections.Generic.IEnumerable<V> Select<U,V>(this System.Collections.Generic.IEnumerable<U>, System.Func<U,V>) (in class Enumerable) System.Linq.IQueryable<V> Select<U,V>(this System.Linq.IQueryable<U>, System.Linq.Expressions.Expression<System.Func<U,V>>) (in class Queryable) Could anyone explain this phenomenon, and what the solution is to fix the error?

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  • child objects in linq

    - by gangt
    I checked before I posted but couldn't find a solution. I'm new to linq and it is draining my brain to understand it. I have an xml and want to use linq to fill object that has a child object. the xml and my linq is below. My issue is on this line TaskItems = t.Elements("taskdetail").ToList<TaskItem>() //this line doesn't work how do I fill this child object? var task1 = from t in xd.Descendants("taskheader") select new { Id = t.Element("id").Value, Name = t.Element("name").Value, IsActive = Convert.ToBoolean(Convert.ToInt16(t.Element("isactive").Value)) TaskItems = t.Elements("taskdetail").ToList<TaskItem>() }; <tasks> <taskheader> <id>1</id> <name>some task</name> <isactive>1</isactive> <taskdetail> <taskid>1</taskid> <name>action1</name> <value>some action</value> </taskdetail> <taskdetail> <taskid>1</taskid> <name>action2</name> <value>some other action</value> </taskdetail> </taskheader> </tasks> public class Task { public int Id; public string Name; public bool IsActive; public List<TaskItem> TaskItems = new List<TaskItem>(); } public class TaskItem { public int TaskId; public string Name; public string Value; }

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  • sql to linq translated code

    - by ognjenb
    SQL: SELECT o.Id, o.OrderNumber, o.Date, d.Name AS 'Distributor', d.Notes AS 'DistrNotes', -- distributer c.Name AS 'Custoer', c.Notes AS 'CustmNotes', -- customer t.Name AS 'Transporter', -- transporter o.InvoiceFile, o.Notes, o.AwbFile, o.TrackingFile, o.Status, o.DeliveryNotification, o.ServiceType, o.ValidityDate, o.DeliveryTime, o.Weight, o.CustomerId, o.CustomerOrderNumber, o.CustomerDate, o.Shipment, o.Payment, o.TransporterId, o.TotalPrice, o.Discount, o.AlreadyPaid, o.Delivered, o.Received, o.OrderEnteredBy, CONCAT(e.Name, ' ', e.Surname) AS 'IBEKO Engineer', o.Confirmed FROM `order` o LEFT JOIN person d ON o.`DistributorId` = d.`Id` LEFT JOIN person c ON o.`CustomerId` = c.Id LEFT JOIN Transporter t ON o.`TransporterId` = t.Id LEFT JOIN IbekoEngineer e ON o.OrderEnteredBy = e.Id LINQ: testEntities6 ordersEntities = new testEntities6(); var orders_query = (from o in ordersEntities.order join pd in ordersEntities.person on o.DistributorId equals pd.Id join pc in ordersEntities.person on o.CustomerId equals pc.Id join t in ordersEntities.transporter on o.TransporterId equals t.Id select new OrdersModel { Id = o.Id, OrderNumber = o.OrderNumber, Date = o.Date, Distributor_Name = pdk.Name, Distributor_Notes = pdk.Notes, Customer_Name = pc.Name, Customer_Notes = pc.Notes, Transporter_Name = t.Name, InvoiceFile = o.InvoiceFile, Notes = o.Notes, AwbFile = o.AwbFile, TrackingFile = o.TrackingFile, Status = o.Status, DeliveryNotification = o.DeliveryNotification, ServiceType = o.ServiceType, ValidityDate = o.ValidityDate, DeliveryTime = o.DeliveryTime, Weight = o.Weight, CustomerId = o.CustomerId, CustomerOrderNumber = o.CustomerOrderNumber, CustomerDate = o.CustomerDate, Shipment = o.Shipment, Payment = o.Payment, TransporterId = o.TransporterId, TotalPrice = o.TotalPrice, Discount = o.Discount, AlreadyPaid = o.AlreadyPaid, Delivered = o.Delivered, Received = o.Received, OrderEnteredBy = o.OrderEnteredBy, Confirmed = o.Confirmed }); I translated the above SQL code into linq. SQL code return data from database but LINQ not return data. Why?

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  • Convert Excel File 'xls' to CSV, CAUTION: Bumps Ahead

    - by faizanahmad
    The task was to provide users with an interface where they can upload the 'csv' files, these files were to be processed and loaded to Database by a Console application. The code in Console application could not handle the 'xls' files so we thought, OK, lets convert 'xls' to 'csv' in the code, Seemed like fun. The idea was to convert it right after uploading within 'csv' file. As Microsoft does not recommend using the  Excel objects in ASP.NET, we decided to use the Jet engine to open xls. (Ace driver is used for xlsx) The code was pretty straight, can be found on following links: http://www.c-sharpcorner.com/uploadfile/yuanwang200409/102242008174401pm/1.aspx http://www.devasp.net/net/articles/display/141.html FIRST BUMP 'OleDbException (0x80004005): Unspecified error' ( Impersonation ): The ablove code ran fine in my test web site and test console application, but it gave an 'OleDbException (0x80004005): Unspecified error' in main web site, turns out imperonation was set to True and as soon as I changed it to False, it did work. on My XP box, web site was running under user                   'ASPNET'  with imperosnation set to FALSE                   'IUSR_*' i.e IIS guest user with impersonation set to TRUE The weired part was that both users had same rights on the folders I was saving files to and on Excel app in DCOM Config.  We decided to give it a try on Windows Server 2003 with web site set to windows authentication ( impersonation = true ) and yes it did work. SECOND BUMP 'External table not in correct format': I got this error with some files and it appeared that the file from client has some metadata issues  ( when I opened the file in Excel and try to save it ,excel  would give me this error saying File can not be saved in current format ) and the error was caused by that. Some people were able to reslove the error by using "Extended Properties=HTML Import;" in connection string. But it did not work for me. We decided to detour from here and use Excel object :( as we had no control on client setting the meta deta of Excel files. Before third bump there were a ouple of small thingies like 'Retrieving the COM class factory for component with CLSID {00024500-0000-0000-C000-000000000046} failed due to the following error: 80070005' Fix can be found at http://blog.crowe.co.nz/archive/2006/03/02/589.aspx THIRD BUMP ( Could not get rid of the EXCEL process  ):  I has all the code in place to 'Quiet' the excel, but, it just did not work. work around was done to Kill the process as we knew no other application on server was using EXCEL.  The normal steps to quite the excel application worked just fine in console application though.   FOURTH BUMP: Code worked with one file 1 on my machine and with the other file 2 code will break. and the same code will work perfectly fine with file 2 on some other machine . We moved it to QA  ( Windows Server 2003 )and worked with every file just perfect. But , then there was another problem: one user can upload it and second cant, permissions on folder and DCOM Conifg checked. Another Detour: Uplooad the xls as it is and convert in Console application.   Lesson Learnt:  If its 'xlsx' use 'ACE Driver' or read xml within excel as recommneded by MS. If xls and you know its always going to be properly formatted  'jet Engine'  Code: Imports Microsoft.Office.Interop Private Function ConvertFile(ByVal SourceFolder As String, ByVal FileName As String, ByVal FileExtension As String)As Boolean     Dim appExcel As New Excel.Application     Dim workBooks As Excel.Workbooks = appExcel.Workbooks     Dim objWorkbook As Excel.Workbook      Try                   objWorkbook = workBooks.Open(CompleteFilePath )                            objWorkbook.SaveAs(Filename:=CObj(SourceFolder & FileName & ".csv"), FileFormat:=Excel.XlFileFormat.xlCSV)       Catch ex As Exception         GenerateAlert(ex.Message().Replace("'", "") & " Error Converting File to CSV.")         LogError(ex )         Return False      Finally                      If Not(objWorkbook is Nothing) then               objWorkbook.Close(SaveChanges:=CObj(False))           End If           ReleaseObj(objWorkbook)                                      ReleaseObj(workBooks)           appExcel.Quit()           ReleaseObj(appExcel)                                 Dim proc As System.Diagnostics.Process           For Each proc In System.Diagnostics.Process.GetProcessesByName("EXCEL")               proc.Kill()           Next         DeleteSourceFile(SourceFolder & FileName & FileExtension)     End Try  Return True  End Function   Private Sub ReleaseObj(ByVal o As Object)     Try      System.Runtime.InteropServices.Marshal.ReleaseComObject(o)   Catch ex As Exception           LogError(ex )   Finally      o = Nothing    End Try End Sub     Protected Sub DeleteSourceFile(Byval CompleteFilePath As string)         Try             Dim MyFile As FileInfo = New FileInfo(CompleteFilePath)             If  MyFile.Exists Then                 File.Delete(CompleteFilePath)             Else              Throw New FileNotFoundException()             End If         Catch ex As Exception             GenerateAlert( " Source File could not be deleted.")              LogError(ex)         End Try     End Sub  The code to kill the process ( Avoid it if you can ): Dim proc As System.Diagnostics.Process For Each proc In System.Diagnostics.Process.GetProcessesByName("EXCEL")     proc.Kill() Next

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  • Logic for capturing unique characteristics in an object array. C# LINQ [closed]

    - by Shawn H.
    Given the following "response" or array of objects, what would be the most efficient way to get the desired results. There must be an easier way than the exhaustive and tedious way I'm doing it now. A LINQ solution would be fantastic. Situation #1 <things> <thing id="1"> <feature>Tall</feature> </thing> <thing id="2"> <feature>Tall</feature> </thing> <thing id="3"> <feature>Tall</feature> <feature>Wide</feature> </thing> <thing id="4"> <feature>Tall</feature> </thing> </things> Result: Wide Situation #2 <things> <thing id="1"> <feature>Short</feature> </thing> <thing id="2"> <feature>Tall</feature> </thing> <thing id="3"> <feature>Tall</feature> <feature>Wide</feature> </thing> <thing id="4"> <feature>Tall</feature> </thing> </things> Result: Wide, Short, Tall Situation #3 <things> <thing id="1"> <feature>Tall</feature> <feature>Thin</feature> </thing> <thing id="2"> <feature>Tall</feature> </thing> <thing id="3"> <feature>Tall</feature> <feature>Wide</feature> </thing> <thing id="4"> <feature>Tall</feature> </thing> </things> Result: Wide, Thin Thanks.

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  • NHibernate LINQ query throws error "Could not resolve property"

    - by Xorandor
    I'm testing out using LINQ with NHibernate but have run into some problems with resolving string.length. I have the following public class DC_Control { public virtual int ID { get; private set; } public virtual string Name { get; set; } public virtual bool IsEnabled { get; set; } public virtual string Url { get; set; } public virtual string Category { get; set; } public virtual string Description { get; set; } public virtual bool RequireScriptManager { get; set; } public virtual string TriggerQueryString { get; set; } public virtual DateTime? DateAdded { get; set; } public virtual DateTime? DateUpdated { get; set; } } public class DC_ControlMap : ClassMap<DC_Control> { public DC_ControlMap() { Id(x => x.ID); Map(x => x.Name).Length(128); Map(x => x.IsEnabled); Map(x => x.Url); Map(x => x.Category); Map(x => x.Description); Map(x => x.RequireScriptManager); Map(x => x.TriggerQueryString); Map(x => x.DateAdded); Map(x => x.DateUpdated); } } private static ISessionFactory CreateSessionFactory() { return Fluently.Configure() .Database(FluentNHibernate.Cfg.Db.MsSqlConfiguration.MsSql2008) .Mappings(m => m.FluentMappings.AddFromAssembly(Assembly.GetExecutingAssembly())) .ExposeConfiguration(c => c.SetProperty("connection.connection_string", "CONNSTRING")) .ExposeConfiguration(c => c.SetProperty("proxyfactory.factory_class", "NHibernate.ByteCode.Castle.ProxyFactoryFactory,NHibernate.ByteCode.Castle")) .BuildSessionFactory(); } public static void test() { using (ISession session = sessionFactory.OpenSession()) { var sqlQuery = session.CreateSQLQuery("select * from DC_Control where LEN(url) > 80").AddEntity(typeof(DC_Control)).List<DC_Control>(); var linqQuery= session.Linq<DC_Control>().Where(c => c.Url.Length > 80).ToList(); } } In my test method I first try and perform the query using SQL, this works just fine. Then I want to do the same thing in LINQ, and it throws the following error: NHibernate.QueryException: could not resolve property: Url.Length of: DC_Control I've searched alot for this "could not resolve property" error, but I can't quite figure out, what this means. Is this because the LINQ implementation is not complete? If so it's a bit disappointing coming from Linq2Sql where this would just work. I also tried it setting up the mapping with a hbm.xml instead of using FluentNHibernate but it produced teh same error.

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  • C# where does the dbml file come from?

    - by 5YrsLaterDBA
    Learning C# and learing Linq now. have lots of qestions about it. Basically I need a step by step tutorial. I suppose the dbml file is the configuration file of the database. I double click it and VS will open it with kind of design diagram. I can create/delete/modify table here? I can use add new item to add the Linq to SQL Classes to get a dbml file? what's next? generate tables in database? generate sql script? generate cs files? when? how?

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  • Entity Framework, what's so bad and what's so good?

    - by AverageJoe719
    Hi all, I am curious as to what your opinions are in Entity Framework? I have read some things like the first version of it is super horrible because it doesn't handle many to many relationships (though many ORMs don't and I've never seen the issue with just making a linking table). Also is LINQ to Entities the same as Entity Framework? I think it is, but it seems like one term is used or the other. I have used Linq to SQL before, what are the advantages of it compared to that? In terms of coding preference I like to build everything from the ground up so I can fully understand it/be in control of the code I write. So I have heard that Entity Framework is harder and I know LinqToSQL handles a lot of stuff automatically, but specifically what are the differences? I appreciate your responses, Thanks =)

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  • How do I get a right outer join in L2E?

    - by Dan
    I have two tables that I set up through the VS Entity Data Model Diagram tool. I'm trying to do a right outer join and it doesn't return results from the 2nd table. I have set up a 0..1 to MANY relationship from the diagram tool. When I run a Linq-To-Entities query, it still defaults to an INNER JOIN. From my understanding of entities, if I set up the relationship using VS, when I join the tables, it should automagically figure out the join syntax based on the relationship I supply. It doesn't seem to be doing that. I am using EF v1 (not Linq-to-Sql). Query I'm running: from s in SomeTable join t in SomeOtherTable on s.ID equals t.ID select new { s.MyFieldName, t.MyOtherFieldName }

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  • Dynamic query to immediate execute?

    - by Curtis White
    I am using the MSDN Dynamic linq to sql package. It allows using strings for queries. But, the returned type is an IQueryable and not an IQueryable<T>. I do not have the ToList() method. How can I this immediate execute without manually enumerating over the IQueryable? My goal is to databind to the Selecting event on a linqtosql datasource and that throws a datacontext disposed exception. I can set the query as the Datasource on a gridview though. Any help greatly appreciated! Thanks. The dynamic linq to sql is the one from the samples that comes with visual studio.

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  • Linq to LLBLGen query problem

    - by Jeroen Breuer
    Hello, I've got a Stored Procedure and i'm trying to convert it to a Linq to LLBLGen query. The query in Linq to LLBGen works, but when I trace the query which is send to sql server it is far from perfect. This is the Stored Procedure: ALTER PROCEDURE [dbo].[spDIGI_GetAllUmbracoProducts] -- Add the parameters for the stored procedure. @searchText nvarchar(255), @startRowIndex int, @maximumRows int, @sortExpression nvarchar(255) AS BEGIN SET @startRowIndex = @startRowIndex + 1 SET @searchText = '%' + @searchText + '%' -- SET NOCOUNT ON added to prevent extra result sets from -- interfering with SELECT statements. SET NOCOUNT ON; -- This is the query which will fetch all the UmbracoProducts. -- This query also supports paging and sorting. WITH UmbracoOverview As ( SELECT ROW_NUMBER() OVER( ORDER BY CASE WHEN @sortExpression = 'productName' THEN umbracoProduct.productName WHEN @sortExpression = 'productCode' THEN umbracoProduct.productCode END ASC, CASE WHEN @sortExpression = 'productName DESC' THEN umbracoProduct.productName WHEN @sortExpression = 'productCode DESC' THEN umbracoProduct.productCode END DESC ) AS row_num, umbracoProduct.umbracoProductId, umbracoProduct.productName, umbracoProduct.productCode FROM umbracoProduct INNER JOIN product ON umbracoProduct.umbracoProductId = product.umbracoProductId WHERE (umbracoProduct.productName LIKE @searchText OR umbracoProduct.productCode LIKE @searchText OR product.code LIKE @searchText OR product.description LIKE @searchText OR product.descriptionLong LIKE @searchText OR product.unitCode LIKE @searchText) ) SELECT UmbracoOverview.UmbracoProductId, UmbracoOverview.productName, UmbracoOverview.productCode FROM UmbracoOverview WHERE (row_num >= @startRowIndex AND row_num < (@startRowIndex + @maximumRows)) -- This query will count all the UmbracoProducts. -- This query is used for paging inside ASP.NET. SELECT COUNT (umbracoProduct.umbracoProductId) AS CountNumber FROM umbracoProduct INNER JOIN product ON umbracoProduct.umbracoProductId = product.umbracoProductId WHERE (umbracoProduct.productName LIKE @searchText OR umbracoProduct.productCode LIKE @searchText OR product.code LIKE @searchText OR product.description LIKE @searchText OR product.descriptionLong LIKE @searchText OR product.unitCode LIKE @searchText) END This is my Linq to LLBLGen query: using System.Linq.Dynamic; var q = ( from up in MetaData.UmbracoProduct join p in MetaData.Product on up.UmbracoProductId equals p.UmbracoProductId where up.ProductCode.Contains(searchText) || up.ProductName.Contains(searchText) || p.Code.Contains(searchText) || p.Description.Contains(searchText) || p.DescriptionLong.Contains(searchText) || p.UnitCode.Contains(searchText) select new UmbracoProductOverview { UmbracoProductId = up.UmbracoProductId, ProductName = up.ProductName, ProductCode = up.ProductCode } ).OrderBy(sortExpression); //Save the count in HttpContext.Current.Items. This value will only be saved during 1 single HTTP request. HttpContext.Current.Items["AllProductsCount"] = q.Count(); //Returns the results paged. return q.Skip(startRowIndex).Take(maximumRows).ToList<UmbracoProductOverview>(); This is my Initial expression to process: value(SD.LLBLGen.Pro.LinqSupportClasses.DataSource`1[Eurofysica.DB.EntityClasses.UmbracoProductEntity]).Join(value(SD.LLBLGen.Pro.LinqSupportClasses.DataSource`1[Eurofysica.DB.EntityClasses.ProductEntity]), up => up.UmbracoProductId, p => p.UmbracoProductId, (up, p) => new <>f__AnonymousType0`2(up = up, p = p)).Where(<>h__TransparentIdentifier0 => (((((<>h__TransparentIdentifier0.up.ProductCode.Contains(value(Eurofysica.BusinessLogic.BLL.Controllers.UmbracoProductController+<>c__DisplayClass1).searchText) || <>h__TransparentIdentifier0.up.ProductName.Contains(value(Eurofysica.BusinessLogic.BLL.Controllers.UmbracoProductController+<>c__DisplayClass1).searchText)) || <>h__TransparentIdentifier0.p.Code.Contains(value(Eurofysica.BusinessLogic.BLL.Controllers.UmbracoProductController+<>c__DisplayClass1).searchText)) || <>h__TransparentIdentifier0.p.Description.Contains(value(Eurofysica.BusinessLogic.BLL.Controllers.UmbracoProductController+<>c__DisplayClass1).searchText)) || <>h__TransparentIdentifier0.p.DescriptionLong.Contains(value(Eurofysica.BusinessLogic.BLL.Controllers.UmbracoProductController+<>c__DisplayClass1).searchText)) || <>h__TransparentIdentifier0.p.UnitCode.Contains(value(Eurofysica.BusinessLogic.BLL.Controllers.UmbracoProductController+<>c__DisplayClass1).searchText))).Select(<>h__TransparentIdentifier0 => new UmbracoProductOverview() {UmbracoProductId = <>h__TransparentIdentifier0.up.UmbracoProductId, ProductName = <>h__TransparentIdentifier0.up.ProductName, ProductCode = <>h__TransparentIdentifier0.up.ProductCode}).OrderBy( => .ProductName).Count() Now this is how the queries look like that are send to sql server: Select query: Query: SELECT [LPA_L2].[umbracoProductId] AS [UmbracoProductId], [LPA_L2].[productName] AS [ProductName], [LPA_L2].[productCode] AS [ProductCode] FROM ( [eurofysica].[dbo].[umbracoProduct] [LPA_L2] INNER JOIN [eurofysica].[dbo].[product] [LPA_L3] ON [LPA_L2].[umbracoProductId] = [LPA_L3].[umbracoProductId]) WHERE ( ( ( ( ( ( ( ( [LPA_L2].[productCode] LIKE @ProductCode1) OR ( [LPA_L2].[productName] LIKE @ProductName2)) OR ( [LPA_L3].[code] LIKE @Code3)) OR ( [LPA_L3].[description] LIKE @Description4)) OR ( [LPA_L3].[descriptionLong] LIKE @DescriptionLong5)) OR ( [LPA_L3].[unitCode] LIKE @UnitCode6)))) Parameter: @ProductCode1 : String. Length: 2. Precision: 0. Scale: 0. Direction: Input. Value: "%%". Parameter: @ProductName2 : String. Length: 2. Precision: 0. Scale: 0. Direction: Input. Value: "%%". Parameter: @Code3 : String. Length: 2. Precision: 0. Scale: 0. Direction: Input. Value: "%%". Parameter: @Description4 : String. Length: 2. Precision: 0. Scale: 0. Direction: Input. Value: "%%". Parameter: @DescriptionLong5 : String. Length: 2. Precision: 0. Scale: 0. Direction: Input. Value: "%%". Parameter: @UnitCode6 : String. Length: 2. Precision: 0. Scale: 0. Direction: Input. Value: "%%". Count query: Query: SELECT TOP 1 COUNT(*) AS [LPAV_] FROM (SELECT [LPA_L2].[umbracoProductId] AS [UmbracoProductId], [LPA_L2].[productName] AS [ProductName], [LPA_L2].[productCode] AS [ProductCode] FROM ( [eurofysica].[dbo].[umbracoProduct] [LPA_L2] INNER JOIN [eurofysica].[dbo].[product] [LPA_L3] ON [LPA_L2].[umbracoProductId] = [LPA_L3].[umbracoProductId]) WHERE ( ( ( ( ( ( ( ( [LPA_L2].[productCode] LIKE @ProductCode1) OR ( [LPA_L2].[productName] LIKE @ProductName2)) OR ( [LPA_L3].[code] LIKE @Code3)) OR ( [LPA_L3].[description] LIKE @Description4)) OR ( [LPA_L3].[descriptionLong] LIKE @DescriptionLong5)) OR ( [LPA_L3].[unitCode] LIKE @UnitCode6))))) [LPA_L1] Parameter: @ProductCode1 : String. Length: 2. Precision: 0. Scale: 0. Direction: Input. Value: "%%". Parameter: @ProductName2 : String. Length: 2. Precision: 0. Scale: 0. Direction: Input. Value: "%%". Parameter: @Code3 : String. Length: 2. Precision: 0. Scale: 0. Direction: Input. Value: "%%". Parameter: @Description4 : String. Length: 2. Precision: 0. Scale: 0. Direction: Input. Value: "%%". Parameter: @DescriptionLong5 : String. Length: 2. Precision: 0. Scale: 0. Direction: Input. Value: "%%". Parameter: @UnitCode6 : String. Length: 2. Precision: 0. Scale: 0. Direction: Input. Value: "%%". As you can see no sorting or paging is done (like in my Stored Procedure). This is probably done inside the code after all the results are fetched. This costs a lot of performance! Does anybody know how I can convert my Stored Procedure to Linq to LLBLGen the proper way?

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  • Parse a CSV file extracting some of the values but not all.

    - by Yallaa
    Good day, I have a local csv file with values that change daily called DailyValues.csv I need to extract the value field of category2 and category4. Then combine, sort and remove duplicates (if any) from the extracted values. Then save it to a new local file NewValues.txt. Here is an example of the DailyValues.csv file: category,date,value category1,2010-05-18,value01 category1,2010-05-18,value02 category1,2010-05-18,value03 category1,2010-05-18,value04 category1,2010-05-18,value05 category1,2010-05-18,value06 category1,2010-05-18,value07 category2,2010-05-18,value08 category2,2010-05-18,value09 category2,2010-05-18,value10 category2,2010-05-18,value11 category2,2010-05-18,value12 category2,2010-05-18,value13 category2,2010-05-18,value14 category2,2010-05-18,value30 category3,2010-05-18,value16 category3,2010-05-18,value17 category3,2010-05-18,value18 category3,2010-05-18,value19 category3,2010-05-18,value20 category3,2010-05-18,value21 category3,2010-05-18,value22 category3,2010-05-18,value23 category3,2010-05-18,value24 category4,2010-05-18,value25 category4,2010-05-18,value26 category4,2010-05-18,value10 category4,2010-05-18,value28 category4,2010-05-18,value11 category4,2010-05-18,value30 category2,2010-05-18,value31 category2,2010-05-18,value32 category2,2010-05-18,value33 category2,2010-05-18,value34 category2,2010-05-18,value35 category2,2010-05-18,value07 I've found some helpful parsing examples at http://www.php.net/manual/en/function.fgetcsv.php and managed to extract all the values of the value column but don't know how to restrict it to only extract the values of category2/4 then sort and clean duplicate. The solution needs to be in php, perl or shell script. Any help would be much appreciated. Thank you in advance.

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  • Data Aggregation of CSV files java

    - by royB
    I have k csv files (5 csv files for example), each file has m fields which produce a key and n values. I need to produce a single csv file with aggregated data. I'm looking for the most efficient solution for this problem, speed mainly. I don't think by the way that we will have memory issues. Also I would like to know if hashing is really a good solution because we will have to use 64 bit hashing solution to reduce the chance for a collision to less than 1% (we are having around 30000000 rows per aggregation). For example file 1: f1,f2,f3,v1,v2,v3,v4 a1,b1,c1,50,60,70,80 a3,b2,c4,60,60,80,90 file 2: f1,f2,f3,v1,v2,v3,v4 a1,b1,c1,30,50,90,40 a3,b2,c4,30,70,50,90 result: f1,f2,f3,v1,v2,v3,v4 a1,b1,c1,80,110,160,120 a3,b2,c4,90,130,130,180 algorithm that we thought until now: hashing (using concurentHashTable) merge sorting the files DB: using mysql or hadoop or redis. The solution needs to be able to handle Huge amount of data (each file more than two million rows) a better example: file 1 country,city,peopleNum england,london,1000000 england,coventry,500000 file 2: country,city,peopleNum england,london,500000 england,coventry,500000 england,manchester,500000 merged file: country,city,peopleNum england,london,1500000 england,coventry,1000000 england,manchester,500000 The key is: country,city. This is just an example, my real key is of size 6 and the data columns are of size 8 - total of 14 columns. We would like that the solution will be the fastest in regard of data processing.

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  • Reading/Writing DataTables to and from an OleDb Database LINQ

    - by jsmith
    My current project is to take information from an OleDbDatabase and .CSV files and place it all into a larger OleDbDatabase. I have currently read in all the information I need from both .CSV files, and the OleDbDatabase into DataTables.... Where it is getting hairy is writing all of the information back to another OleDbDatabase. Right now my current method is to do something like this: OleDbTransaction myTransaction = null; try { OleDbConnection conn = new OleDbConnection("PROVIDER=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + Database); conn.Open(); OleDbCommand command = conn.CreateCommand(); string strSQL; command.Transaction = myTransaction; strSQL = "Insert into TABLE " + "(FirstName, LastName) values ('" + FirstName + "', '" + LastName + "')"; command.CommandType = CommandType.Text; command.CommandText = strSQL; command.ExecuteNonQuery(); conn.close(); catch (Exception) { // IF invalid data is entered, rolls back the database myTransaction.Rollback(); } Of course, this is very basic and I'm using an SQL command to commit my transactions to a connection. My problem is I could do this, but I have about 200 fields that need inserted over several tables. I'm willing to do the leg work if that's the only way to go. But I feel like there is an easier method. Is there anything in LINQ that could help me out with this?

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