Search Results

Search found 6048 results on 242 pages for 'linq to dataset'.

Page 18/242 | < Previous Page | 14 15 16 17 18 19 20 21 22 23 24 25  | Next Page >

  • DataSet v/s Database

    - by Hemanshu Bhojak
    While designing applications it is a very good practice to have all the business logic in one place. So why then we sometimes have the business logic in stored procs? Can we fetch all data from the DB and store it in a DataSet and then process it? What would be the performance of the app in this scenario?

    Read the article

  • Extend linq-to-sql partial class to avoid writing a property?

    - by Curtis White
    I have a linq-to-sql class. I have a property "Password" for which I want to call the underlying ASP.NET Membership provider. Thus, I do not want this property written out directly but via my own code. I basically want to create a facade/proxy for this property such that I may use the underlying membership provider or a custom stored procedure. I want to accomplish without modifying the LINQ-TO-SQL designer generated code, if at all possible.

    Read the article

  • Linq 2 Sybase ASE database? What are the options?

    - by Scott Weinstein
    I have a need to query an existing Sybase ASE database and would like to use Linq syntax for my data retrival. I don't need write access, nor do I need the full set of Linq operators, just Select(), SelectMany(), Where(), and GroupJoin() What are options are available? In particular, I'm wondering about nHibernate and building a new Linq2Sybase provider based on the IQ toolkit.

    Read the article

  • What is the difference between these 2 XML LINQ Queries?

    - by Jon
    I have the 2 following LINQ queries and I haven't quite got my head around LINQ so what is the difference between the 2 approaches below? Is there a circumstance where one approach is better than another? ChequeDocument.Descendants("ERRORS").Where(x=>(string)x.Attribute("D") == "").Count(); (from x in ChequeDocument.Descendants("ERRORS") where (string)x.Attribute("D") == "" select x).Count())

    Read the article

  • How to use LINQ for CRUD with a simple SQL table?

    - by Rob Ferno
    Every LINQ blog I found there seemed around 2 years old, I understand the syntax but need more direction on creating the SQL mapping and context classes. I just need to use LINQ for 2 SQL tables I have, nothing complicated. Do folks write the SQL mapping classes by hand for such cases or is there a decent tool for this? Can someone point me in the right direction?

    Read the article

  • Read xml file and import only one table from multiple tables from xml file in the dataset at a time.

    - by Harikrishna
    I want to store the data in the xml file and retrieve the data from that. I have defined more than table in that xml file.Now to read the tables I am using dataset ds = new dataset(); ds.ReadXml(xmlfilepath); Now this dataset contains all the tables those are in xml file when we read the xml file into dataset. But I want only one specified table at a time in a dataset by condition. Like there are PersonalInfo,OtherInfo,PropertiesInfo tables in the xml file. But I want only OtherInfo table in dataset what I should do ?

    Read the article

  • Preserving DataRowState when serializing DataSet using DataContractSerializer

    - by user349453
    For various reasons I am having to send a typed dataset to a WCF service endpoint. This works fine except that upon Deserializing, the RowState of each row in each DataTable is set to 'Added', regardless of what they were on the client. If I write the serialized stream out to a file, I see that the RowState is not part of the Serialized data. How can I add this so that I can preserve the RowState across service boundaries? Not that I think it matters, but the client process is running .net 3.5 while the service process is running .net 4.0

    Read the article

  • Why can't I see the 'dataset project' property in Visual Studio DataSet designer?

    - by Ryan
    Hi, I am trying to follow 'n tier app design' tutorials and they tell me to set the DataSet Project property from the Data Set Designer in VS, to split table adaptors and entities into seprate projects. I can't see that property! (I'm looking in the same place shown on the videos... all other properties match) Does anybody know why? The video is here http://windowsclient.net/learn/video.aspx?v=14625 (4:36 is where the property is set) I'm using VS c# 2008 Express, with SQL Server Express 2008. Thanks a lot for any help Ryan

    Read the article

  • DataSet.GetXml not returning null results

    - by pistacchio
    Hi, whenever I convert a DatSet into an XML with DataSet.GetXml, any null value is ignored, so, where i expect this: <value1>a</value1> <value2></value2> <value3>c</value3> I get this instead: <value1>a</value1> <value3>c</value3> Any quick and dirty way to handle this? Thanks EDIT: I think a solution would be using WriteXml. Could anyone provide me with a sample of using it WITHOUT writing to a file but getting a string just like GetXml does? Thanks

    Read the article

  • Inserting Rows in Relationship using a Strongly Typed DataSet

    - by Manuel Faux
    I'm using ADO.NET with a strongly typed dataset in C# (.NET 3.5). I want to insert a new row to two tables which are related in an 1:n relation. The table Attachments holds the primary key part of the relation and the table LicenseAttachments holds the foreign key part. AttachmentsDataSet.InvoiceRow invoice; // Set to a valid row, also referenced in InvoiceAttachments AttachmentsDataSet.AttachmentsRow attachment; attachment = attachmentsDataSet.Attachments.AddAttachmentsRow("Name", "Description"); attachmentsDataSet.InvoiceAttachments.AddInvoiceAttachmentsRow(invoice, attachment); Of course when I first update the InvoicesAttachments table, I'll get a foreign key violation from the SQL server, so I tried updating the Attachments table first, which will create the rows, but will remove the attachment association in the InvoiceAttachments table. Why? How do I solve this problem?

    Read the article

  • Is it just me? I find LINQ to XML to be sort of cumbersome, compared to XPath.

    - by Cheeso
    I am a C# programmer, so I don't get to take advantage of the cool XML syntax in VB. Dim itemList1 = From item In rss.<rss>.<channel>.<item> _ Where item.<description>.Value.Contains("LINQ") Or _ item.<title>.Value.Contains("LINQ") Using C#, I find XPath to be easier to think about, easier to code, easier to understand, than performing a multi-nested select using LINQ to XML. Look at this syntax, it looks like Greek swearing: var waypoints = from waypoint in gpxDoc.Descendants(gpx + "wpt") select new { Latitude = waypoint.Attribute("lat").Value, Longitude = waypoint.Attribute("lon").Value, Elevation = waypoint.Element(gpx + "ele") != null ? waypoint.Element(gpx + "ele").Value : null, Name = waypoint.Element(gpx + "name") != null ? waypoint.Element(gpx + "name").Value : null, Dt = waypoint.Element(gpx + "cmt") != null ? waypoint.Element(gpx + "cmt").Value : null }; All the casting, the heavy syntax, the possibility for NullPointerExceptions. None of this happens with XPath. I like LINQ in general, and I use it on object collections and databases, but my first go-round with querying XML led me right back to XPath. Is it just me? Am I missing something? EDIT: someone voted to close this as "not a real question". But it is a real question, stated clearly. The question is: Am I misunderstanding something with LINQ to XML?

    Read the article

  • Load DataSet into an XML Document - C#.Net

    - by NLV
    Hello I'm trying to read a dataset as xml and load it into an XML Document. XmlDocument contractHistoryXMLSchemaDoc = new XmlDocument(); using (MemoryStream ms = new MemoryStream()) { //XmlWriterSettings xmlWSettings = new XmlWriterSettings(); //xmlWSettings.ConformanceLevel = ConformanceLevel.Auto; using (XmlWriter xmlW = XmlWriter.Create(ms)) { xmlW.WriteStartDocument(); dsContract.WriteXmlSchema(xmlW); xmlW.WriteEndDocument(); xmlW.Close(); using (XmlReader xmlR = XmlReader.Create(ms)) { contractHistoryXMLSchemaDoc.Load(xmlR); } } } But i'm getting the error - "Root Element Missing". Any ideas? NLV

    Read the article

  • how create a sql database fom a stongly typed dataset

    - by Keith Vinson
    I'm looking for an easy way to transfer a database schema I have developed inside visual studio as a strongly typed dataset (xsd file) into a corresponding sql server database. Silly me I assumed the process would be forthright, but I can't find out how to do it. I assume I could duplicate the tables column by column, but that seems so error prone. Does anyone know of a way to perform the schema transfer like this? Maybe a tool to translate the xsd file into a corresponding sql server ddl file? Final thought once I have the schema transferred moving data around between the two data stores will be straight forward, its just getting the schemas synced that has me stumped... Thanks, Keith

    Read the article

  • create a dataset by using modulo division method

    - by ayoom
    create a dataset with 101 integers. Use the modulo division method of hashing to store the random data values into hash tables with table sizes of 7, 51, and 151. Use the linear probing and quadratic method of collision resolution. Print out the tables after the data values have been stored. Search for 10 different values in each of the three hash tables, counting the number of comparisons necessary. Print out the number of comparisons necessary in each case, in tabular form.

    Read the article

  • How do I connect a dataGrid to a DataSet

    - by orangecl4now
    using System.Windows; namespace Telephone_Directory { /// <summary> /// Interaction logic for MainWindow.xaml /// </summary> public partial class MainWindow : Window { public MainWindow() { InitializeComponent(); telephone2010DataSet dataSet = new telephone2010DataSet(); telephone2010DataSetTableAdapter adapter = new telephone2010DataSetTableAdapter(); } } } The above is my code is a new project. Visual Studio 2010 complains that " the type or namespace 'telephone2010DataSetTableAdapter' could not be found." I created a new solution. I right clicked the solution name and selected "Add Existing Item" and located my Microsoft Access DB file. I followed the wizard and it setup the necessary XSD files. I started coding and I got this message. I did a little google-ing and I cant figure it out. This is a WPF application created with Visual Studio 2010.

    Read the article

  • How to insert many rows of data from arrays/lists to SQL Server (DataSet, DataTable)

    - by Kamil
    I need little help with transferring data from variables, arrays, lists to my SQL Server. Im not bad in SQL, but im not familiar with DataSet, DataTable objects. My data is now stored in list of strings (List). Every string in that list looks similar to this: QWERTY,19920604,0.91,0.35,0.34,0.35,343840 There are about 900000 rows like this. Target datatypes in SQL Server: BIGINT (primary key, im not inserting it, its identity(1,1)) VARCHAR(10), DATE, DECIMAL(10,2), DECIMAL(10,2), DECIMAL(10,2), DECIMAL(10,2), INT How to convert that data to SQL Server data types? How to insert that data into SQL Server? Also i need some progress bar updates between inserts. I could do this using old-fashion SQL command, but i have learn more modern way :)

    Read the article

  • Simple, but I'm stuck ....Updating a DataSet using code

    - by user2518039
    I have a simple Windows form in VB: textbox bound thru an adapter and a bindingsource to my dataset. I have a button that on Click I want it to update the database. The form loads and the first data row shows in the textbox, I change the text then click my button but no update happens. Any ideas what I'm doing wrong, or how I should do this?? Public Class Form1 Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load Me.AToolsTableAdapter.Fill(Me.Qedsandb_TroyDataSet.aTools) End Sub Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click AToolsTableAdapter.Update(Qedsandb_TroyDataSet.aTools) End Sub End Class

    Read the article

  • How can I stop an auto-generated Linq to SQL class from loading ALL data?

    - by Gary McGill
    DUPLICATE of http://stackoverflow.com/questions/2433422/how-can-i-stop-an-auto-generated-linq-to-sql-class-from-loading-all-data post answers there! I have an ASP.NET MVC project, much like the NerdDinner tutorial example. (I'm using MVC 2, but followed the NerdDinner tutorial in order to create it). As per the instructions in part 3 of the tutorial, I've created a Linq-to-SQL model of my database by creating a "Linq to SQL Classes" (.dbml) surface, and dropping my database tables onto it. The designer has automatically added relationships between the generated classes based on my database tables. Let's say that my classes are as per the NerdDinner example, so I have Dinner and RSVP tables, where each Dinner record is associated with many RSVP records - hence in the generated classes, the Dinner object has a RSVPs property which is a list of RSVP objects. My problem is this: it appears (and I'd be gladly proved wrong on this) that as soon as I access a Dinner object, it's loading all of the corresponding RSVP objects, even if I don't use the RSVPs member. First question: is this really the default behavior for the generated classes? In my particular situation, the object graph contains many more tables (which have an order of magnitude more records), and so this is disastrous behaviour - I'd be loading tons of data when all I want to do is show the details of a single parent record. Second question: are there any properties exposed through the designer UI that would let me modify this behavior? (I can't find any). Third question: I've seen a description of how to control the loading of related records in a DataContext by using a DataShape object associated with the DataContext. Is that what I'm meant to do, and if so are there any tutorials like the NerdDinner one that would show not only how to do it, but also suggest a 'pattern' for normal use?

    Read the article

  • How can I create a dynamic LINQ query in C# with possible multiple group by clauses?

    - by FordPrefect141
    I have been a programmer for some years now but I am a newcomer to LINQ and C# so forgive me if my question sounds particularly stupid. I hope someone may be able to point me in the right direction. My task is to come up with the ability to form a dynamic multiple group by linq query within a c# script using a generic list as a source. For example, say I have a list containing multiple items with the following structure: FieldChar1 - character FieldChar2 - character FieldChar3 - character FieldNum1 - numeric FieldNum2 - numeric In a nutshell I want to be able to create a LINQ query that will sum FieldNum1 and FieldNum2 grouped by any one, two or all three of the FieldChar fields that will be decided at runtime depending on the users requirements as well as selecting the FieldChar fields in the same query. I have the dynamic.cs in my project which icludes a GroupByMany extension method but I have to admit I am really not sure how to put these to use. I am able to get the desired results if I use a query with hard-wired group by requests but not dynamically. Apologies for any erroneous nomenclature, I am new to this language but any advice would be most welcome. Many thanks Alex

    Read the article

  • LINQ thinks I need an extra INNER JOIN, but why?

    - by Saurabh Kumar
    I have a LINQ query, which for some reason is generating an extra/duplicatre INNER JOIN. This is causing the query to not return the expected output. If I manually comment that extra JOIN from the generated SQL, then I get seemingly correct output. Can you detect what I might have done i nthis LINQ to have cuased this extra JOIN? Thanks. Here is my approx LINQ var ids = context.Code.Where(predicate); var rs = from r in ids group r by new { r.phonenumbers.person.PersonID} into g let matchcount=g.Select(p => p.phonenumbers.PhoneNum).Distinct().Count() where matchcount ==2 select new { personid = g.Key }; and here is the generated SQL (the duplicate join is [t7]) Declare @p1 VarChar(10)='Home' Declare @p2 VarChar(10)='111' Declare @p3 VarChar(10)='Office' Declare @p4 VarChar(10)='222' Declare @p5 int=2 SELECT [t9].[PersonID] AS [pid] FROM ( SELECT [t3].[PersonID], ( SELECT COUNT(*) FROM ( SELECT DISTINCT [t7].[PhoneValue] FROM [dbo].[Person] AS [t4] INNER JOIN [dbo].[PersonPhoneNumber] AS [t5] ON [t5].[PersonID] = [t4].[PersonID] INNER JOIN [dbo].[CodeMaster] AS [t6] ON [t6].[Code] = [t5].[PhoneType] INNER JOIN [dbo].[PersonPhoneNumber] AS [t7] ON [t7].[PersonID] = [t4].[PersonID] WHERE ([t3].[PersonID] = [t4].[PersonID]) AND ([t6].[Enumeration] = @p0) AND ((([t6].[CodeDescription] = @p1) AND ([t5].[PhoneValue] = @p2)) OR (([t6].[CodeDescription] = @p3) AND ([t5].[PhoneValue] = @p4))) ) AS [t8] ) AS [value] FROM ( SELECT [t0].[PersonID] FROM [dbo].[Person] AS [t0] INNER JOIN [dbo].[PersonPhoneNumber] AS [t1] ON [t1].[PersonID] = [t0].[PersonID] INNER JOIN [dbo].[CodeMaster] AS [t2] ON [t2].[Code] = [t1].[PhoneType] WHERE ([t2].[Enumeration] = @p0) AND ((([t2].[CodeDescription] = @p1) AND ([t1].[PhoneValue] = @p2)) OR (([t2].[CodeDescription] = @p3) AND ([t1].[PhoneValue] = @p4))) GROUP BY [t0].[PersonID] ) AS [t3] ) AS [t9] WHERE [t9].[value] = @p5

    Read the article

  • Linq-to-SQL produces bad SQL?

    - by strager
    I am trying to run a Linq-to-SQL query, but when the query is evaluated, I get the following exception: System.Data.OleDb.OleDbException was unhandled Message=The SELECT statement includes a reserved word or an argument name that is misspelled or missing, or the punctuation is incorrect. Source=Microsoft JET Database Engine ErrorCode=-2147217900 StackTrace: at System.Data.OleDb.OleDbCommand.ExecuteCommandTextErrorHandling(OleDbHResult hr) at System.Data.OleDb.OleDbCommand.ExecuteCommandTextForSingleResult(tagDBPARAMS dbParams, Object& executeResult) at System.Data.OleDb.OleDbCommand.ExecuteCommandText(Object& executeResult) at System.Data.OleDb.OleDbCommand.ExecuteCommand(CommandBehavior behavior, Object& executeResult) at System.Data.OleDb.OleDbCommand.ExecuteReaderInternal(CommandBehavior behavior, String method) at System.Data.OleDb.OleDbCommand.ExecuteReader(CommandBehavior behavior) at System.Data.OleDb.OleDbCommand.ExecuteDbDataReader(CommandBehavior behavior) at System.Data.Common.DbCommand.ExecuteReader() at System.Data.Linq.SqlClient.SqlProvider.Execute(Expression query, QueryInfo queryInfo, IObjectReaderFactory factory, Object[] parentArgs, Object[] userArgs, ICompiledSubQuery[] subQueries, Object lastResult) at System.Data.Linq.SqlClient.SqlProvider.ExecuteAll(Expression query, QueryInfo[] queryInfos, IObjectReaderFactory factory, Object[] userArguments, ICompiledSubQuery[] subQueries) at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query) at System.Data.Linq.DataQuery`1.System.Linq.IQueryProvider.Execute[S](Expression expression) at System.Linq.Queryable.FirstOrDefault[TSource](IQueryable`1 source) at xxx.InventoryPopulator`2.Clear(String barcode) in F:\Projects\C#\xxx\xxx\InventoryPopulator.cs:line 38 [..etc..] InnerException: The debugger shows my query is: SELECT [t0].[SupplierID] AS [Id], [t0].[SupplierSKU] AS [Sku], [t0].[LocalSKU] AS [LocalSku], [t0].[ManufacturersBarcode] AS [Barcode], [t0].[QuantityAvailable] FROM [inventorySupplier] AS [t0] WHERE [t0].[ManufacturersBarcode] = @p0 And the Linq query which generates the above is: var items = from item in this.supplierItems where item.Barcode == barcode select item; How do I fix my query?

    Read the article

  • Is this an example of LINQ-to-SQL?

    - by Edward Tanguay
    I made a little WPF application with a SQL CE database. I built the following code with LINQ to get data out of the database, which was surprisingly easy. So I thought "this must be LINQ-to-SQL". Then I did "add item" and added a "LINQ-to-SQL classes" .dbml file, dragged my table onto the Object Relational Designer but it said, "The selected object uses an unsupported data provider." So then I questioned whether or not the following code actually is LINQ-to-SQL, since it indeed allows me to access data from my SQL CE database file, yet officially "LINQ-to-SQL" seems to be unsupported for SQL CE. So is the following "LINQ-to-SQL" or not? using System.Linq; using System.Data.Linq; using System.Data.Linq.Mapping; using System.Windows; namespace TestLinq22 { public partial class Window1 : Window { public Window1() { InitializeComponent(); MainDB db = new MainDB(@"Data Source=App_Data\Main.sdf"); var customers = from c in db.Customers select new {c.FirstName, c.LastName}; TheListBox.ItemsSource = customers; } } [Database(Name = "MainDB")] public class MainDB : DataContext { public MainDB(string connection) : base(connection) { } public Table<Customers> Customers; } [Table(Name = "Customers")] public class Customers { [Column(DbType = "varchar(100)")] public string FirstName; [Column(DbType = "varchar(100)")] public string LastName; } }

    Read the article

  • Pass Linq Expression to a function

    - by Kushan Hasithe Fernando
    I want to pass a property list of a class to a function. with in the function based on property list I'm going to generate a query. As exactly same functionality in Linq Select method. Here I'm gonna implement this for Ingress Database. As an example, in front end I wanna run a select as this, My Entity Class is like this public class Customer { [System.Data.Linq.Mapping.ColumnAttribute(Name="Id",IsPrimaryKey=true)] public string Id { get; set; } [System.Data.Linq.Mapping.ColumnAttribute(Name = "Name")] public string Name { get; set; } [System.Data.Linq.Mapping.ColumnAttribute(Name = "Address")] public string Address { get; set; } [System.Data.Linq.Mapping.ColumnAttribute(Name = "Email")] public string Email { get; set; } [System.Data.Linq.Mapping.ColumnAttribute(Name = "Mobile")] public string Mobile { get; set; } } I wanna call a Select function like this, var result = dataAccessService.Select<Customer>(C=>C.Name,C.Address); then,using result I can get the Name and Address properties' values. I think my Select function should looks like this, ( *I think this should done using Linq Expression. But im not sure what are the input parameter and return type. * ) Class DataAccessService { // I'm not sure about this return type and input types, generic types. public TResult Select<TSource,TResult>(Expression<Func<TSource,TResult>> selector) { // Here using the property list, // I can get the ColumnAttribute name value and I can generate a select query. } } This is a attempt to create a functionality like in Linq. But im not an expert in Linq Expressions. There is a project call DbLinq from MIT, but its a big project and still i couldn't grab anything helpful from that. Can someone please help me to start this, or can someone link me some useful resources to read about this.

    Read the article

< Previous Page | 14 15 16 17 18 19 20 21 22 23 24 25  | Next Page >