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  • Can we bind dynamic data (dataset or list) to a control in WPF

    - by Anish
    Hi, I have a user control...and the base page(s) which uses this user control has a dataset which will be used by the user control. My dataset is dynamic...means..it can have different number of columns depending upon which page my usercontrol is implemented. Is there any control in wpf which i can use to bind this dataset (without knowing the column information) ...i mean similar to datagrid/gridview in 2.0 ?

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  • iphone send send dataset to .net web service

    - by rocky
    I got a .net web service with dataset as one of the intake parameter. e.g. int HellowWorld(dataset ds) {} After this web service being invoked, it will start processing and return status (success or fail) after the process finished. My question is, how iphone application can build a dataset and attach it as a parameter for sending to the web service?

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  • Some Problem In Using DataSet.ReadXML

    - by Chong
    hi friends, i want to use dataset.readxml for retrieve some data from xml file.But,my xml format is not well format,one part is for dataset and another part for other things.so,how i retrieve the dataset part.i am developing in c#.net 2008.xml file format is like below. <Object type="Sample"> <Object type="Tool"> <Property name="Text">Prescription1</Property> <Property name="Name">Prescription1</Property> <Object type="TextBox"> <Property name="Text">Singapore</Property> <Property name="Name">TextBox2</Property> </Object> <DataSet> //This Part <TableOne> <ItemID>001</ItemID> <ItemName>Item001</ItemName> <Price>100</Price> </TableOne> <TableOne> <ItemID>002</ItemID> <ItemName>Item002</ItemName> <Price>200</Price> </TableOne> </DataSet> </Object> regards Chong

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  • Draw chart for every row of the dataset in SSRS. Loop through dataset rows

    - by Rushme
    Hi, Could anyone help me with how can we create chart for every row of the dataset in SSRS (rdl) ! Suppose the dataset has the following data Name Age ------- ------- A 25 B 26 C 22 3 chart needs to be drawn for the x-axis/y-axis combination of A/25, B/26, C/22. How can I loop through rows of the dataset. And how can I restrict the chart to that particular data point. What would be the xsl expression corresponding to this functionality.

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  • Getting minimum - Min() - for DateTime column in a DataTable using LINQ to DataSets?

    - by Jay Stevens
    I need to get the minimum DateTime value of a column in a DataTable. The DataTable is generated dynamically from a CSV file, therefore I don't know the name of that column until runtime. Here is code I've got that doesn't work... private DateTime GetStartDateFromCSV(string inputFile, string date_attr) { EnumerableRowCollection<DataRow> table = CsvStreamReader.GetDataTableFromCSV(inputFile, "input", true).AsEnumerable(); DateTime dt = table.Select(record => record.Field<DateTime>(date_attr)).Min(); return dt; } The variable table is broken out just for clarity. I basically need to find the minimum value as a DateTime for one of the columns (to be chosen at runtime and represented by date_attr). I have tried several solutions from SO (most deal with known columns and/or non-DateTime fields). What I've got throws an error at runtime telling me that it can't do the DateTime conversion (that seems to be a problem with Linq?) I've confirmed that the data for the column name that is in the string date_attr is a date value.

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  • A Trio of Presentations: Little Wonders, StyleCop, and LINQ/Lambdas

    - by James Michael Hare
    This week is a busy week for me.  First of all I’m giving another presentation on a LINQ/Lambda primer for the rest of the developers in my company.  Of Lambdas and LINQ View more presentations from BlackRabbitCoder Then this Saturday the 25th of June I’ll be reprising my Little Wonders presentation for the Kansas City Developers Camp.  If you are in the area I highly recommend attending and seeing the other great presentations as well.  Their link is here. Little Wonders View more presentations from BlackRabbitCoder Finally, this Monday the 27th I’ll be speaking at the Saint Louis .NET Users group, giving my Automating Code Standards Using StyleCop and FxCop presentation.  If you are in the Saint Louis area stop by!  There’s two other simultaneous presentations as well if they’re more suited to your interests.  The link for the SLDNUG is here. Automating C# Coding Standards using StyleCop and FxCop View more presentations from BlackRabbitCoder Tweet Technorati Tags: C#,.NET,LINQ,Lambda,StyleCop,FxCop,Little Wonders

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  • Macro to Add using System.Linq

    - by Aligned
    I have Visual Studio 2010 setup to remove and sort settings on save with the Power Commands extensions. This is great, but sometimes it removes the using System.Linq at the top. I also find myself scrolling to the top to add the using when I first add System.Linq. So I wrote a quick macro to do it for me. Sub AddUsingLinq()        DTE.ActiveDocument.Selection.StartOfDocument()        DTE.ActiveDocument.Selection.StartOfLine(vsStartOfLineOptions.vsStartOfLineOptionsFirstText)        DTE.ActiveDocument.Selection.Text = "using System.Linq;"        DTE.ActiveDocument.Selection.NewLine()        DTE.ExecuteCommand("Edit.FormatDocument")        DTE.ExecuteCommand("Edit.RemoveAndSort")        DTE.ActiveDocument.Save() DTE.ExecuteCommand("View.NavigateBackward")    End SubHook this up to a shortcut (tools -> options -> keyboard, I chose ctrl + x, c) and you'll be moving faster than ever.

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  • Entity Framework 4.0: Optimal and horrible SQL

    - by DigiMortal
    Lately I had Entity Framework 4.0 session where I introduced new features of Entity Framework. During session I found out with audience how Entity Framework 4.0 can generate optimized SQL. After session I also showed guys one horrible example about how awful SQL can be generated by Entity Framework. In this posting I will cover both examples. Optimal SQL Before going to code take a look at following model. There is class called Event and I will use this class in my query. Here is the LINQ To Entities query that uses small anonymous type. var query = from e in _context.Events             select new { Id = e.Id, Title = e.Title }; Debug.WriteLine(((ObjectQuery)query).ToTraceString()); Running this code gives us the following SQL. SELECT      [Extent1].[event_id] AS [event_id],      [Extent1].[title] AS [title]  FROM [dbo].[events] AS [Extent1] This is really small – no additional fields in SELECT clause. Nice, isn’t it? Horrible SQL Ayende Rahien blog shows us darker side of Entiry Framework 4.0 queries. You can find comparison betwenn NHibernate, LINQ To SQL and LINQ To Entities from posting What happens behind the scenes: NHibernate, Linq to SQL, Entity Framework scenario analysis. In this posting I will show you the resulting query and let you think how much better it can be done. Well, it is not something we want to see running in our servers. I hope that EF team improves generated SQL to acceptable level before Visual Studio 2010 is released. There is also morale of this example: you should always check out the queries that O/R-mapper generates. Behind the curtains it may silently generate queries that perform badly and in this case you need to optimize you data querying strategy. Conclusion Entity Framework 4.0 is new product with a lot of new features and it is clear that not everything is 100% super in its first release. But it still great step forward and I hope that on 12.04.2010 we have new promising O/R-mapper available to use in our projects. If you want to read more about Entity Framework 4.0 and Visual Studio 2010 then please feel free to follow this link to list of my Visual Studio 2010 and .NET Framework 4.0 postings.

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  • Getting the first result from a LINQ query - why does ElementAt<T>(0) fails when First<T>() succeeds

    - by Mr Roys
    I have a method AddStudent() which looks for a student with the same name and returns an existing student from the database if there is a student with the same name, otherwise it creates a new student and adds it to the database. I'm curious why se = students.First<StudentEntity>(); succeeds when se = students.ElementAt<StudentEntity>(0); fails when I try to get the first result from the LINQ query. Aren't the two methods the same? The full code for the method is shown below. public Student AddStudent(string name) { using (SchoolEntities db = new SchoolEntities()) { // find student with same name via LINQ var students = from s in db.StudentEntitySet where s.name == name select s; StudentEntity se = default(StudentEntity); // if student with the same name is already present, return // that student if (students.Count<StudentEntity>() > 0) { // if i use ElementAt, if fails with a "LINQ to Entities does not // recognize the method 'StudentEntity ElementAt[StudentEntity] // (System.Linq.IQueryable`1[StudentEntity], Int32)' method, // and this method cannot be translated into a store expression.", // but not when I use First. Why? // se = students.ElementAt<StudentEntity>(0); se = students.First<StudentEntity>(); } else { // passing 0 for first parameter (id) since it's represented by // a BigInt IDENTITY field in the database so any value // doesn't matter. se = StudentEntity.CreateStudentEntity(0, name); db.AddToStudentEntitySet(se); db.SaveChanges(); } // create a Student object from the Entity object return new Student(se); } } Thanks!

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  • 'LINQ query plan' horribly inefficient but 'Query Analyser query plan' is perfect for same SQL!

    - by Simon_Weaver
    I have a LINQ to SQL query that generates the following SQL : exec sp_executesql N'SELECT COUNT(*) AS [value] FROM [dbo].[SessionVisit] AS [t0] WHERE ([t0].[VisitedStore] = @p0) AND (NOT ([t0].[Bot] = 1)) AND ([t0].[SessionDate] > @p1)',N'@p0 int,@p1 datetime', @p0=1,@p1='2010-02-15 01:24:00' (This is the actual SQL taken from SQL Profiler on SQL Server 2008.) The query plan generated when I run this SQL from within Query Analyser is perfect. It uses an index containing VisitedStore, Bot, SessionDate. The query returns instantly. However when I run this from C# (with LINQ) a different query plan is used that is so inefficient it doesn't even return in 60 seconds. This query plan is trying to do a key lookup on the clustered primary key which contains a couple million rows. It has no chance of returning. What I just can't understand though is that the EXACT same SQL is being run - either from within LINQ or from within Query Analyser yet the query plan is different. I've ran the two queries many many times and they're now running in isolation from any other queries. The date is DateTime.Now.AddDays(-7), but I've even hardcoded that date to eliminate caching problems. Is there anything i can change in LINQ to SQL to affect the query plan or try to debug this further? I'm very very confused!

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  • How to use different providers for Linq to entities?

    - by Anders Svensson
    I'm trying to familiarize myself a bit more with database programming, and I'm looking at different ways of creating a data access layer for applications. I've tried out a few ways but there is such a jungle of different database technologies that I don't know what to learn. For instance I've tried using datasets with tableadapters. Using that I am able to switch data provider rather easily (by programming against the interfaces such as IDbConnection). This is one thing I would want to achieve. But I also know everyone's talking about LINQ, and I'm trying to get to know that a bit better too. So I have tried using Linq to Sql classes as the data access layer as well, but apparently this is not provider independent (works only for SQL Server). So then I read about the Entity Framework (which just as Linq to SQL apparently has gotten its share of bashing already...). It's supposed to be provider independent everybody says, but how? I tried out a tutorial to create an entity data model, but the only providers to choose from were SQL Server/Express. Just for learning purposes, I would like to know how to use the entity framework with MS Access/OleDb. Also, I would appreciate some input on what is the preferred database technology for data access. Is it LINQ still after all the bashing, or should you just use datasets because they are provider independent? Any pointers for what to learn would be great, because it's just too much to learn it all if I'm not going to use it in the end...!

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  • Backup and Restore a SQLCE .sdf database

    - by Ruben Trancoso
    My application needs to backup and restore .sdf files. There is a single dataSet the the whole application and some bindngSource and table adapters on forms using this same dataset. Just for a sake of test I tryied to copy the .sdf in runtime for a backup folder and back to restore it and I got my application not finding the file like it was not there anymore. How should I manage connections to open and close the database since the dataSet do it automaticaly at begin and end of my application?

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  • Reading DBF with VFPOLEDB driver problem.

    - by John Sheares
    I am using VFPOLEDB driver to read DBF files and I keep getting this error and I am not sure why and how to fix the problem: The provider could not determine the Decimal value. For example, the row was just created, the default for the Decimal column was not available, and the consumer had not yet set a new Decimal value. Here is the code. I call this routine to return a DataSet of the DBF file and display the data in a DataGridView. public DataSet GetDBFData(FileInfo fi, string tbl) { using (OleDbConnection conn = new OleDbConnection( @"Provider=VFPOLEDB.1;Data Source=" + fi.DirectoryName + ";")) { conn.Open(); string command = "SELECT * FROM " + tbl; OleDbDataAdapter da = new OleDbDataAdapter(command, conn); DataSet ds = new DataSet(); da.Fill(ds); return ds; } }

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  • Binding Programatically Generated Datasets To Report Viewer

    - by mavera
    Today I researched about reportviewer to use it in my project. As I see the samples and tutorials in the web, We should create an dataset file to Solution Explorer and bind it to report viewer to show data. However I want to create dataset programatically like sample code below. And I want to bind it. Dim ds As New DataSet DB_Gateway.myDataSet("select * from users", ds, "users") How can I do it?

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  • Run SQL Queries on DataTables, or similar, in .Net, without an RDBMS

    - by FastAl
    I'd like to have a dataset or datatables, and be able to run SQL statements on them, without using any external RDBMS. For Example, to take take 2 datatables in a dataset and just join them outright with a SQL statement and Where clause, the result being a new datatable? For example if I have 2 datatables, named People and Addresses in a dataset (that I built using code, not getting from a database .. pardon the old fashioned Join syntax): dim dtJoined as DataTable = MyDataSet.RunSQLQuery ("Select * from People, Orders Where People.PersonID=Orders.OrdereID") Thanks

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  • How to do binding programmically?

    - by user175908
    Hello, Could anyone identify the problem in this code? (I'm kinda newbie in WPF bindings.) This code executes after chart is loaded when I click a button: I get this error: Update: I dont get that error anymore. Thanks to Tomas. Now no error occur but chart looks completely blank (no columns) Update: Code now looks like this: // create a very simple DataSet var dataSet = new DataSet("MyDataSet"); var table = dataSet.Tables.Add("MyTable"); table.Columns.Add("Name"); table.Columns.Add("Price"); table.Rows.Add("Brick", 1.5d); table.Rows.Add("Soap", 4.99d); table.Rows.Add("Comic Book", 0.99d); // chart series var series = new ColumnSeries() { IndependentValueBinding = new Binding("[Name]"), // How to deal with DependentValueBinding = new Binding("[Price]"), // these two? ItemsSource = dataSet.Tables[0].DefaultView // or maybe I do mistake here? }; // ---------- set additional binding as adviced ------------------ series.SetBinding(ColumnSeries.ItemsSourceProperty, new Binding()); // chart stuff MyChart.Series.Add(series); MyChart.Title = "Names 'n Prices"; // some code to remove legend var style = new Style(typeof(Control)); style.Setters.Add(new Setter(LegendItem.TemplateProperty, null)); MyChart.LegendStyle = style; XAML: <Window x:Class="BindingzTest.MainWindow" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="MainWindow" Height="606" Width="988" xmlns:charting="clr-namespace:System.Windows.Controls.DataVisualization.Charting;assembly=System.Windows.Controls.DataVisualization.Toolkit"> <Grid Name="LayoutRoot"> <charting:Chart Name="MyChart" Margin="0,0,573,0" Height="289" VerticalAlignment="Top" /> <Button Content="Button" Height="23" HorizontalAlignment="Left" Margin="272,361,0,0" Name="button1" VerticalAlignment="Top" Width="75" Click="chart1_Loaded" /> </Grid> Thanks for help in advance once more.

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  • How to handle encrypted column in SQL Server Database in LINQ to SQL?

    - by Raja
    Hi Guys, We are in the process of encrypting all the SSN columns (had to do it now due to security audit). We already built the DBML and now we have to change it. Can you guys let me know if there is a good way of handling this in LINQ to SQL? We use stored procedures for Insert, Update and Delete but use LINQ to SQL for all our selects (ease of use). Do I have to change the format for those tables with SSN or Is there any other manner we can handle it in LINQ to SQL? Thanks, Raja

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  • How to specify dynamic field names in a Linq where clause?

    - by Dr. Zim
    If you create a Filter object that contains criteria for Linq that normally goes in a where clause like this: var myFilterObject = FilterFactory.GetBlank(); myFilterObject.AddCondition("Salary", "lessThan", "40000"); var myResult = myRepository.GetEmployees(myFilterObject); How would you match the Linq field to the Field Name without using a big case statement? return from e in db.Employee where e.Salary < 40000 select new IList<EmployeeViewModel> { Name= e.name, Salary= e.Salary }; I assume you need to send an object to the Repository that specifies filtering so that you only pull what records you need. I assume Linq doesn't pre-compile (unless you create a customized delegate and function), so you should be able to dynamically specify which fields you want to filter. It would be nice if you could do something like e["Salary"] like some type of Expando Object.

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  • How to convert linq entitySet AND CHILDREN to lists?

    - by Abe Miessler
    I ran into an error when trying to serialize a linq entitySet. To get around this i converted the entitySet to a list. The problem I have run into now is that it's child entity sets are not converting to a list and when I try to serialize the parent those are now throwing an error. Does anyone know of a way to convert a linq entitySet AND it's children to lists? p.s. I'm new to linq so if any of this dosn't make sense let me know

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  • Linq to SQL Azure genrating Error "Specified cast is not valid."

    - by Rabbi
    B"H I have an application that has been working for months using Linq to SQL connecting to a SQLExpress. I tried migrating it to SQL Azure. I copied the structure and data using the Sync Framework. I viewed the data in SQL Azure using SSMS 2008 R2 and it seams to be exactly what I have in my Sql Server. However when I try to use Linq to SQL against it I get an error "Specified cast is not valid." I seams to be happening any time I get child records. i.e. whenever I fill (the first time I access) an entity set. It seams to be happening after the data returns and when Linq tries to put it into the objects. remember, the application is working perfectly against sqlexpress, even when accessed across the internet or vpn.

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  • Entity framework (3.5): How to translate a certain LINQ query to eSQL?

    - by Sebastian P.R. Gingter
    Hi there, I have the following LINQ query that I need to translate to Entity SQL /eSQL): return (ObjectQuery<User>) from user in Users where !user.Roles.Any(r => r.AnIntegerProperty < 0) select user; User.Roles is an navigation property to the n:m relation to Roles and there also is a Role.Users navigation property the other way round. There aren't User_Roles or Roles_User Entities available in the model, and I can't add these. I also can't use the LINQ statement here, because I need to add .OrderBy("it." + propertyname) (comes from another source, can't change that too) later on which is not possible if the ObjectQuery is build with linq. So how do I translate this to eSQL? And where can I find good eSQL samples? I searched for a whole day until now and must admit that eSQL reference is lousy and there aren't any usable examples around the web.

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  • Is ORM (Linq, Hibernate...) really that useful?

    - by Peter
    I have been playing with some LINQ ORM (LINQ directly to SQL) and I have to admit I like its expressive powers . For small utility-like apps, It also works quite fast: dropping a SQL server on some surface and you're set to linq away. For larger apps however, the DAL never was that big of an issue to me to setup, nor maintain, and more often than not, once it was set, all the programming was not happening there anyway... My, honest - I am an ORM newbie - question : what is the big advantage of ORM over writing a decent DAL by hand? (seems like a double, couldn't find it though) UPDATE : OK its a double :-) I found it myself eventually : ORM vs Handcoded Data Access Layer

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