Search Results

Search found 5846 results on 234 pages for 'linq to crm'.

Page 33/234 | < Previous Page | 29 30 31 32 33 34 35 36 37 38 39 40  | Next Page >

  • how to bind gridview through linq

    - by Manoj Wadhwani
    I am using linq to sql Currently i am binding gridviw through linq which query written in business logic call . i have extract record through query in business logic class and i want to bind that particular data to gridviw and return data . how to retrun data which type is array. code is mention below: CMSBusiness.DataClasses1DataContext db = new DataClasses1DataContext(); var cate = from p in db.categoryTables select new { categoryId=p.categoryId, categoryName=p.categoryName, categoryDesc=p.categoryDesc }; how to return value and bind gridview , Please suggest

    Read the article

  • LINQ nested joins

    - by ace
    Im trying to convert a SQL join to LINQ. I need some help in getting the nested join working in LINQ. This is my SQL query, Ive cut it short just to show the nested join in SQL: LEFT OUTER JOIN dbo.TaskCommentRecipient RIGHT OUTER JOIN dbo.TaskComment ON dbo.TaskCommentRecipient.TaskCommentID = dbo.TaskComment.TaskCommentID ON dbo.Task.Taskid = dbo.TaskComment.TaskCommentTaskId

    Read the article

  • Search by Letters using LINQ

    - by Biswo
    hi i m using Linq & C# and i want to filter my data as this syntax in Sql Syntax in sql is I hav one table name Customer in which name is field 'Select name from customer where name like 'C%'' can u help to solve this code in Linq

    Read the article

  • .Net Linq - Join together all item of a List

    - by Melursus
    How can I write a Linq expression that select item from a List and join them together ? Example IList<string> data = new List<string>(); data.Add("MyData1"); data.Add("MyData2"); string result = //some linq query... I try data.Select(x => x + ","); //result = "MyData1, MyData2"

    Read the article

  • how to specify literal value in linq union

    - by lowlyintern
    I have the following SQL query, note I want the literal value '0' in the second field in the second SELECT statement from the ItemSale table. How do I express this in LINQ? I get the error message 'Invalid anonymous type member declarator'. SELECT BranchNumber,QuantitySold FROM Department UNION SELECT BranchNumber,0 FROM ItemSale How to express the '0' in LINQ? var unionQuery = (from dept in Department select new { dept.BranchNumber, dept.QuantitySold, }) .Concat(from item in ItemSale select new { item.BranchNumber, 0 });

    Read the article

  • How do linq Last() work?

    - by acidzombie24
    I dont understand how current can be null and last can be an object while last being a LINQ function. I thought last uses GetEnumerator and keeps going until current == null and returns the object. However as you can see the first GetEnumerator().Current is null and last somehow returns an object. How do linq Last() work? var.GetEnumerator().Current var.Last()

    Read the article

  • Data access layer using Linq to SQL

    - by Andrei Tanasescu
    I am building a c# - linq - sql server winforms/asp.net application, accessing a database. I would like my business logic layer to be easily testable, and that means not littering it with Linq database queries everywhere. What design patterns/ best practices are available for the following use cases - inserting/updating a new object - searching for an object - loading a bunch of related data into a sort of "presentation" object that could be displayed by various views ?

    Read the article

  • LINQ - joining multiple lists

    - by kristian
    I've looked at the 101 Linq Samples here but I can't see anything like this in that list. If I'm just not seeing a relevant example there, please link to it. If I have these 3 classes: class Student { int id; string name } class Course { int id, string name } class Enrolment { int studentId; int courseId; } How would I use LINQ to get a list of courses a student is enrolled on? (assume I have an IList of all three classes)

    Read the article

  • Linq to XSD processing

    - by goel
    For Typed Xml to Linq processing ,do i need to download Linq to XSD alpha installer or is it available in VS 2008 ? (I am using VS 2008 Professional edition).

    Read the article

  • Cast problem with LINQ

    - by yigit
    I'm tring to get my product's types to a list with Linq. var types = (from t in NHibernateSession.Linq<Product>() select t.Type).Distinct().ToList<Type>(); return types; But its giving an Unable to cast object of type error '...Domain.Product' to type '...Domain.Type'. Please tell where am I going wrong.

    Read the article

  • Should I be learning Linq, Direct SQL Commands (in .net), EF or other?

    - by Wil
    Basically, I have a very good knowledge of plain old SQL coming from Classic ASP programming. Over the past couple of months, I have been learning C# and today was my first full day at MVC 3 (Razor) which I am loving! I need to get back in to Databases and I know that writing SqlCommand everywhere is obviously outdated (although it is nice I can still do it!). I used to go to a great usergroup as an IT Pro and the developer stuff went completely over my head, however I do remember a few things which kept coming up such as LINQ... However, that was some time ago and now the same people on Twitter are saying how out dated it is. I have tried to do research on both and I am clueless as to what direction I should go in, or when to use one over another (if learning both is a good thing). I am more so confused as I thought EF was a part of the .Net Framework, however, reading through the quick start guide, I had to download a component using Nuget. ... Basically I am out of my depth here and just need some honest advice of where to go!

    Read the article

  • Use CompiledQuery.Compile to improve LINQ to SQL performance

    - by Michael Freidgeim
    After reading DLinq (Linq to SQL) Performance and in particular Part 4  I had a few questions. If CompiledQuery.Compile gives so much benefits, why not to do it for all Linq To Sql queries? Is any essential disadvantages of compiling all select queries? What are conditions, when compiling makes whose performance, for how much percentage? World be good to have default on application config level or on DBML level to specify are all select queries to be compiled? And the same questions about Entity Framework CompiledQuery Class. However in comments I’ve found answer  of the author ricom 6 Jul 2007 3:08 AM Compiling the query makes it durable. There is no need for this, nor is there any desire, unless you intend to run that same query many times. SQL provides regular select statements, prepared select statements, and stored procedures for a reason.  Linq now has analogs. Also from 10 Tips to Improve your LINQ to SQL Application Performance   If you are using CompiledQuery make sure that you are using it more than once as it is more costly than normal querying for the first time. The resulting function coming as a CompiledQuery is an object, having the SQL statement and the delegate to apply it.  And your delegate has the ability to replace the variables (or parameters) in the resulting query. However I feel that many developers are not informed enough about benefits of Compile. I think that tools like FxCop and Resharper should check the queries  and suggest if compiling is recommended. Related Articles for LINQ to SQL: MSDN How to: Store and Reuse Queries (LINQ to SQL) 10 Tips to Improve your LINQ to SQL Application Performance Related Articles for Entity Framework: MSDN: CompiledQuery Class Exploring the Performance of the ADO.NET Entity Framework - Part 1 Exploring the Performance of the ADO.NET Entity Framework – Part 2 ADO.NET Entity Framework 4.0: Making it fast through Compiled Query

    Read the article

  • Dynamics CRM Customer Portal Accelerator Installation

    - by saturdayplace
    (I've posted this question on the codeplex forums too, but have yet to get a response) I've got an on-premise installation of CRM and I'm trying to hook the portal to it. My connection string in web.config: <connectionStrings> <add name="Xrm" connectionString="Authentication Type=AD; Server=http://myserver:myport/MyOrgName; User ID=mydomain\crmwebuser; Password=thepassword" /> </connectionStrings> And my membership provider: <membership defaultProvider="CustomCRMProvider"> <providers> <add connectionStringName="Xrm" applicationName="/" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="true" passwordFormat="Hashed" minRequiredPasswordLength="1" minRequiredNonalphanumericCharacters="0" name="CustomCRMProvider" type="System.Web.Security.SqlMembershipProvider" /> </providers> </membership> Now, I'm super new to MS style web development, so please help me if I'm missing something. In Visual Studio 2010, when I go to Project ASP.NET Configuration it launches the Web Site Administration Tool. When I click the Security Tab there, I get the following error: There is a problem with your selected data store. This can be caused by an invalid server name or credentials, or by insufficient permission. It can also be caused by the role manager feature not being enabled. Click the button below to be redirected to a page where you can choose a new data store. The following message may help in diagnosing the problem: An error occurred while attempting to initialize a System.Data.SqlClient.SqlConnection object. The value that was provided for the connection string may be wrong, or it may contain an invalid syntax. Parameter name: connectionString I can't see what I'm doing wrong here. Does the user mydomain\crmwebuser need certain permissions in the SQL database, or somewhere else? edit: On the home page of the Web Site Administration Tool, I have the following: **Application**:/ **Current User Name**:MACHINENAME\USERACCOUNT Which is obviously a different set of credentials than mydomain\crmwebuser. Is this part of the problem?

    Read the article

  • MS Dynamics CRM trapping .NET error before I can handle it

    - by clifgriffin
    This is a fun one. I have written a custom search page that provides faster, more user friendly searches than the default Contacts view and also allows searching of Leads and Contacts simultaneously. It uses GridViews bound to SqlDataSources that query filtered views. I'm sure someone will complain that I'm not using the web services for this, but this is just the design decision we made. These GridViews live in UpdatePanels to enable very slick AJAX updates upon search. It's all working great. Nearly ready to be deployed, except for one thing: Some long running searches are triggering an uncatchable SQL timeout exception. [SqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.] at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection) at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj) at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj) at System.Data.SqlClient.SqlDataReader.ConsumeMetaData() at System.Data.SqlClient.SqlDataReader.get_MetaData() at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString) at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result) at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method) at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method) at System.Data.SqlClient.SqlCommand.ExecuteDbDataReader(CommandBehavior behavior) at System.Data.Common.DbCommand.System.Data.IDbCommand.ExecuteReader(CommandBehavior behavior) at System.Data.Common.DbDataAdapter.FillInternal(DataSet dataset, DataTable[] datatables, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior) at System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, Int32 startRecord, Int32 maxRecords, String srcTable, IDbCommand command, CommandBehavior behavior) at System.Data.Common.DbDataAdapter.Fill(DataSet dataSet, String srcTable) at System.Web.UI.WebControls.SqlDataSourceView.ExecuteSelect(DataSourceSelectArguments arguments) at System.Web.UI.DataSourceView.Select(DataSourceSelectArguments arguments, DataSourceViewSelectCallback callback) at System.Web.UI.WebControls.DataBoundControl.PerformSelect() at System.Web.UI.WebControls.BaseDataBoundControl.DataBind() at System.Web.UI.WebControls.GridView.DataBind() at System.Web.UI.WebControls.BaseDataBoundControl.EnsureDataBound() at System.Web.UI.WebControls.CompositeDataBoundControl.CreateChildControls() at System.Web.UI.Control.EnsureChildControls() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Control.PreRenderRecursiveInternal() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) I found that CRM is doing a server.transfer to capture this error because my UpdatePanels started throwing JavaSript errors when this error would occur. I was only able to get the full error message by using the JavaScript debugger in IE. Having found this error, I thought the solution would be simple. I just needed to wrap my databind calls in try/catch blocks to capture any errors. Unfortunately it seems CRM's IIS configuration has the magic ability to capture this error before it ever gets back to my code. Using the debugger I never see it. It never gets to my catch blocks, but it's clearly happening in the SQL Data Source which is clearly (by the stack trace) being triggered by my GridView bind. Any ideas on this? It's driving me crazy. Code Behind (with some irrelevant functions omitted): protected void Page_Load(object sender, EventArgs e) { //Initialize some stuff this.bannerOracle = new OdbcConnection(ConfigurationManager.ConnectionStrings["OracleConnectionString"].ConnectionString); //Prospect default HideProspects(); HideProspectAddressColumn(); //Contacts default HideContactAddressColumn(); //Default error messages gvContacts.EmptyDataText = "Sad day. Your search returned no contacts."; gvProspects.EmptyDataText = "Sad day. Your search returned no prospects."; //New search try { SearchContact(null, -1); } catch { gvContacts.EmptyDataText = "Oops! An error occured. This may have been a timeout. Please try your search again."; gvContacts.DataSource = null; gvContacts.DataBind(); } } protected void txtSearchString_TextChanged(object sender, EventArgs e) { if(!String.IsNullOrEmpty(txtSearchString.Text)) { try { SearchContact(txtSearchString.Text, Convert.ToInt16(lstSearchType.SelectedValue)); } catch { gvContacts.EmptyDataText = "Oops! An error occured. This may have been a timeout. Please try your search again."; gvContacts.DataSource = null; gvContacts.DataBind(); } if (chkProspects.Checked == true) { try { SearchProspect(txtSearchString.Text, Convert.ToInt16(lstSearchType.SelectedValue)); } catch { gvProspects.EmptyDataText = "Oops! An error occured. This may have been a timeout. Please try your search again."; gvProspects.DataSource = null; gvProspects.DataBind(); } finally { ShowProspects(); } } else { HideProspects(); } } } protected void SearchContact(string search, int type) { SqlCRM_Contact.ConnectionString = ConfigurationManager.ConnectionStrings["MSSQLConnectionString"].ConnectionString; gvContacts.DataSourceID = "SqlCRM_Contact"; string strQuery = ""; string baseQuery = @"SELECT filteredcontact.contactid, filteredcontact.new_libertyid, filteredcontact.fullname, 'none' AS line1, filteredcontact.emailaddress1, filteredcontact.telephone1, filteredcontact.birthdateutc AS birthdate, filteredcontact.gendercodename FROM filteredcontact "; switch(type) { case LASTFIRST: strQuery = baseQuery + "WHERE fullname LIKE @value AND filteredcontact.statecode = 0"; SqlCRM_Contact.SelectCommand = strQuery; SqlCRM_Contact.SelectParameters.Add("value", DbType.String, search.Trim() + "%"); break; case LAST: strQuery = baseQuery + "WHERE lastname LIKE @value AND filteredcontact.statecode = 0"; SqlCRM_Contact.SelectCommand = strQuery; SqlCRM_Contact.SelectParameters.Add("value", DbType.String, search.Trim() + "%"); break; case FIRST: strQuery = baseQuery + "WHERE firstname LIKE @value AND filteredcontact.statecode = 0"; SqlCRM_Contact.SelectCommand = strQuery; SqlCRM_Contact.SelectParameters.Add("value", DbType.String, search.Trim() + "%"); break; case LIBERTYID: strQuery = baseQuery + "WHERE new_libertyid LIKE @value AND filteredcontact.statecode = 0"; SqlCRM_Contact.SelectCommand = strQuery; SqlCRM_Contact.SelectParameters.Add("value", DbType.String, search.Trim() + "%"); break; case EMAIL: strQuery = baseQuery + "WHERE emailaddress1 LIKE @value AND filteredcontact.statecode = 0"; SqlCRM_Contact.SelectCommand = strQuery; SqlCRM_Contact.SelectParameters.Add("value", DbType.String, search.Trim() + "%"); break; case TELEPHONE: strQuery = baseQuery + "WHERE telephone1 LIKE @value AND filteredcontact.statecode = 0"; SqlCRM_Contact.SelectCommand = strQuery; SqlCRM_Contact.SelectParameters.Add("value", DbType.String, search.Trim() + "%"); break; case BIRTHDAY: strQuery = baseQuery + "WHERE filteredcontact.birthdateutc BETWEEN @dateStart AND @dateEnd AND filteredcontact.statecode = 0"; try { DateTime temp = DateTime.Parse(search); if (temp.Year < 1753 || temp.Year > 9999) { search = string.Empty; } else { search = temp.ToString("yyyy-MM-dd"); } } catch { search = string.Empty; } SqlCRM_Contact.SelectCommand = strQuery; SqlCRM_Contact.SelectParameters.Add("dateStart", DbType.String, search.Trim() + " 00:00:00.000"); SqlCRM_Contact.SelectParameters.Add("dateEnd", DbType.String, search.Trim() + " 23:59:59.999"); break; case SSN: //Do something break; case ADDRESS: strQuery = @"SELECT contactid, new_libertyid, fullname, line1, emailaddress1, telephone1, birthdate, gendercodename FROM (SELECT FC.contactid, FC.new_libertyid, FC.fullname, FA.line1, FC.emailaddress1, FC.telephone1, FC.birthdateutc AS birthdate, FC.gendercodename, ROW_NUMBER() OVER(PARTITION BY FC.contactid ORDER BY FC.contactid DESC) AS rn FROM filteredcontact FC INNER JOIN FilteredCustomerAddress FA ON FC.contactid = FA.parentid WHERE FA.line1 LIKE @value AND FA.addressnumber <> 1 AND FC.statecode = 0 ) AS RESULTS WHERE rn = 1"; SqlCRM_Contact.SelectCommand = strQuery; SqlCRM_Contact.SelectParameters.Add("value", DbType.String, search.Trim() + "%"); ShowContactAddressColumn(); break; default: strQuery = @"SELECT TOP 500 filteredcontact.contactid, filteredcontact.new_libertyid, filteredcontact.fullname, 'none' AS line1, filteredcontact.emailaddress1, filteredcontact.telephone1, filteredcontact.birthdateutc AS birthdate, filteredcontact.gendercodename FROM filteredcontact WHERE filteredcontact.statecode = 0"; SqlCRM_Contact.SelectCommand = strQuery; break; } if (type != ADDRESS) { HideContactAddressColumn(); } gvContacts.PageIndex = 0; //try //{ // SqlCRM_Contact.DataBind(); //} //catch //{ // SqlCRM_Contact.DataBind(); //} gvContacts.DataBind(); } protected void SearchProspect(string search, int type) { SqlCRM_Prospect.ConnectionString = ConfigurationManager.ConnectionStrings["MSSQLConnectionString"].ConnectionString; gvProspects.DataSourceID = "SqlCRM_Prospect"; string strQuery = ""; string baseQuery = @"SELECT filteredlead.leadid, filteredlead.fullname, 'none' AS address1_line1, filteredlead.emailaddress1, filteredlead.telephone1, filteredlead.lu_dateofbirthutc AS lu_dateofbirth, filteredlead.lu_gendername FROM filteredlead "; switch (type) { case LASTFIRST: strQuery = baseQuery + "WHERE fullname LIKE @value AND filteredlead.statecode = 0"; SqlCRM_Prospect.SelectCommand = strQuery; SqlCRM_Prospect.SelectParameters.Add("value", DbType.String, search.Trim() + "%"); break; case LAST: strQuery = baseQuery + "WHERE lastname LIKE @value AND filteredlead.statecode = 0"; SqlCRM_Prospect.SelectCommand = strQuery; SqlCRM_Prospect.SelectParameters.Add("value", DbType.String, search.Trim() + "%"); break; case FIRST: strQuery = baseQuery + "WHERE firstname LIKE @value AND filteredlead.statecode = 0"; SqlCRM_Prospect.SelectCommand = strQuery; SqlCRM_Prospect.SelectParameters.Add("value", DbType.String, search.Trim() + "%"); break; case LIBERTYID: strQuery = baseQuery + "WHERE new_libertyid LIKE @value AND filteredlead.statecode = 0"; SqlCRM_Prospect.SelectCommand = strQuery; SqlCRM_Prospect.SelectParameters.Add("value", DbType.String, search.Trim() + "%"); break; case EMAIL: strQuery = baseQuery + "WHERE emailaddress1 LIKE @value AND filteredlead.statecode = 0"; SqlCRM_Prospect.SelectCommand = strQuery; SqlCRM_Prospect.SelectParameters.Add("value", DbType.String, search.Trim() + "%"); break; case TELEPHONE: strQuery = baseQuery + "WHERE telephone1 LIKE @value AND filteredlead.statecode = 0"; SqlCRM_Prospect.SelectCommand = strQuery; SqlCRM_Prospect.SelectParameters.Add("value", DbType.String, search.Trim() + "%"); break; case BIRTHDAY: strQuery = baseQuery + "WHERE filteredlead.lu_dateofbirth BETWEEN @dateStart AND @dateEnd AND filteredlead.statecode = 0"; try { DateTime temp = DateTime.Parse(search); if (temp.Year < 1753 || temp.Year > 9999) { search = string.Empty; } else { search = temp.ToString("yyyy-MM-dd"); } } catch { search = string.Empty; } SqlCRM_Prospect.SelectCommand = strQuery; SqlCRM_Prospect.SelectParameters.Add("dateStart", DbType.String, search.Trim() + " 00:00:00.000"); SqlCRM_Prospect.SelectParameters.Add("dateEnd", DbType.String, search.Trim() + " 23:59:59.999"); break; case SSN: //Do nothing break; case ADDRESS: strQuery = @"SELECT filteredlead.leadid, filteredlead.fullname, filteredlead.address1_line1, filteredlead.emailaddress1, filteredlead.telephone1, filteredlead.lu_dateofbirthutc AS lu_dateofbirth, filteredlead.lu_gendername FROM filteredlead WHERE address1_line1 LIKE @value AND filteredlead.statecode = 0"; SqlCRM_Prospect.SelectCommand = strQuery; SqlCRM_Prospect.SelectParameters.Add("value", DbType.String, search.Trim() + "%"); ShowProspectAddressColumn(); break; default: strQuery = @"SELECT TOP 500 filteredlead.leadid, filteredlead.fullname, 'none' AS address1_line1 filteredlead.emailaddress1, filteredlead.telephone1, filteredlead.lu_dateofbirthutc AS lu_dateofbirth, filteredlead.lu_gendername FROM filteredlead WHERE filteredlead.statecode = 0"; SqlCRM_Prospect.SelectCommand = strQuery; break; } if (type != ADDRESS) { HideProspectAddressColumn(); } gvProspects.PageIndex = 0; //try //{ // SqlCRM_Prospect.DataBind(); //} //catch (Exception ex) //{ // SqlCRM_Prospect.DataBind(); //} gvProspects.DataBind(); }

    Read the article

  • LINQ - Select Statement - The null value cannot be assigned to a member with type System.Int32 which

    - by thiag0
    I am trying to achieve the following... _4S.NJB_Request request = (from r in db.NJB_Requests where r.RequestId == referenceId select r).Take(1).SingleOrDefault(); Getting the following exception... Message: The null value cannot be assigned to a member with type System.Int32 which is a non-nullable value type. StackTrace: 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.SingleOrDefault[TSource](IQueryable`1 source) at DAL.SqlDataProvider.MarkNJBPCRequestAsComplete(Int32 referenceId, Int32 processState) I have verified that 'referenceId' does have a value. Anyone know why this would happen in a select statement? Thanks!

    Read the article

  • Linq to SQL and concurrency with Rob Conery repository pattern

    - by David Hall
    I have implemented a DAL using Rob Conery's spin on the repository pattern (from the MVC Storefront project) where I map database objects to domain objects using Linq and use Linq to SQL to actually get the data. This is all working wonderfully giving me the full control over the shape of my domain objects that I want, but I have hit a problem with concurrency that I thought I'd ask about here. I have concurrency working but the solution feels like it might be wrong (just one of those gitchy feelings). The basic pattern is: private MyDataContext _datacontext private Table _tasks; public Repository(MyDataContext datacontext) { _dataContext = datacontext; } public void GetTasks() { _tasks = from t in _dataContext.Tasks; return from t in _tasks select new Domain.Task { Name = t.Name, Id = t.TaskId, Description = t.Description }; } public void SaveTask(Domain.Task task) { Task dbTask = null; // Logic for new tasks omitted... dbTask = (from t in _tasks where t.TaskId == task.Id select t).SingleOrDefault(); dbTask.Description = task.Description, dbTask.Name = task.Name, _dataContext.SubmitChanges(); } So with that implementation I've lost concurrency tracking because of the mapping to the domain task. I get it back by storing the private Table which is my datacontext list of tasks at the time of getting the original task. I then update the tasks from this stored Table and save what I've updated This is working - I get change conflict exceptions raised when there are concurrency violations, just as I want. However, it just screams to me that I've missed a trick. Is there a better way of doing this? I've looked at the .Attach method on the datacontext but that appears to require storing the original version in a similar way to what I'm already doing. I also know that I could avoid all this by doing away with the domain objects and letting the Linq to SQL generated objects all the way up my stack - but I dislike that just as much as I dislike the way I'm handling concurrency.

    Read the article

  • LINQ into SortedList

    - by Chris Simmons
    I'm a complete LINQ newbie, so I don't know if my LINQ is incorrect for what I need to do or if my expectations of performance are too high. I've got a SortedList of objects, keyed by int; SortedList as opposed to SortedDictionary because I'll be populating the collection with pre-sorted data. My task is to find either the exact key or, if there is no exact key, the one with the next higher value. If the search is too high for the list (e.g. highest key is 100, but search for 105), return null. // The structure of this class is unimportant. Just using // it as an illustration. public class CX { public int KEY; public DateTime DT; } static CX getItem(int i, SortedList<int, CX> list) { var items = (from kv in list where kv.Key >= i select kv.Key); if (items.Any()) { return list[items.Min()]; } return null; } Given a list of 50,000 records, calling getItem 500 times takes about a second and a half. Calling it 50,000 times takes over 2 minutes. This performance seems very poor. Is my LINQ bad? Am I expecting too much? Should I be rolling my own binary search function?

    Read the article

  • Delphi Prism and LINQ to SQL / Entity Framework

    - by Vegar
    I have found many posts and examples of using LINQ-syntax in Delphi Prism (Oxygene), but I have never found anything on LINQ to SQL or Entity Framework. Is it possible to use LINQ to SQL or Entity Framework together with Prism? Where can I found such an example? Update: Olaf is giving an answer through his blog The question is now if any visual tools and code generation is provided, or if everything must be done by hand... Second update: Olaf has answered the tool/code generation-question in a comment on his site: The class designer is there, but there is no Pascal code gen. According to marc hoffman that is currently not on their list. For now you have to live with manual mapping. I guess, if you had Visual Studio (not just the VS shell), that you could add a C# library project to your solution, reference that from your Prism project. Then create the Table-Class mapping in the C# project using the visual designer. Maybe somewhat ugly, but possibly the key to get the Designer + CodeGen integrated into Prism. Who cares what language is used for the mapping . I will say this is a 1 - 0 to c# vs prism. If I did not care which language is used for the mapping - why should I care about which language is used for the rest?

    Read the article

  • LINQ-to-SQL: Could not find key member 'x' of key 'x' on type 'y'

    - by Austin Hyde
    I am trying to connect my application to a SQLite database with LINQ-to-SQL, and so far everything has worked fine. The only hitch was that the SQLite provider I am using does not support code generation (unless I was doing something wrong), so I manually coded the 4 tables in the DB. The solution builds properly, but will not run, giving me the error message Could not find key member 'ItemType_Id' of key 'ItemType_Id' on type 'Item'. The key may be wrong or the field or property on 'Item' has changed names. I have checked and double checked spellings and field names on the database and in the attribute mappings, but could not find any problems. The SQL for the table looks like this: CREATE TABLE [Items] ( [Id] integer PRIMARY KEY AUTOINCREMENT NOT NULL, [Name] text NOT NULL, [ItemType_Id] integer NOT NULL ); And my mapping code: [Table(Name="Items")] class Item { // [snip] [Column(Name = "Id", IsPrimaryKey=true, IsDbGenerated=true)] public int Id { get; set; } // [snip] [Column(Name="ItemType_Id")] public int ItemTypeId { get; set; } [Association(Storage = "_itemType", ThisKey = "ItemType_Id")] public ItemType ItemType { get { return _itemType.Entity; } set { _itemType.Entity = value; } } private EntityRef<ItemType> _itemType; // [snip] } This is really my first excursion into LINQ-to-SQL, and am learning as I go, but I cannot seem to get past this seeming simple problem. Why cannot LINQ see my association?

    Read the article

  • extracting RDL data using LINQ

    - by BobC
    I'm working with some SQL Report definition files (RDLs), using LINQ to extract component query statements for validation. I'm trying to extract the <DataSet> elements from under the <DataSets> element. I seem to be getting hung up with one of the elements under <DataSet><Fields><Field> which has a namespace qualifier <rd:TypeName> I've been using LINQ to XML for other parts of the files where there is no namespace qualifiers with no trouble, by specifying a default namespace. The RDL specifies two namespaces: xmlns="http://schemas.microsoft.com/sqlserver/reporting/2005/01/reportdefinition" xmlns:rd="http://schemas.microsoft.com/SQLServer/reporting/reportdesigner"> When I try to get the <DataSets> element, however, I get the following error: System.Xml.XmlException - The ':' character, hexadecimal value 0x3A, cannot be included in a name. I know it has to do with the namespace qualifier (rd:) in one of the child elements, but I'm having difficulty getting a LINQ expression that works. Any help would be appreciated. Thanks!

    Read the article

< Previous Page | 29 30 31 32 33 34 35 36 37 38 39 40  | Next Page >