Querying a Runtime Dataset with LINQ

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- Previous
  - 1
    - GC.Collect() not cleaning memory, how to find out what references to lots of memory still exist? GC.Collect() not cleaning memory, how to find out what references to lots of memory still exist? When all my processign is done i set everything to null and then: GC.Collect(); and then GC.WaitForPendingFinalizers(); but it still shows that my process takes 400 MB of memory. Is there any easy way to see what references that I forgot to set to null so that the memory cleas up on GC.Collect() ? Tag: Querying a Runtime Dataset with LINQ Tag: 144992
  - 2
    - slowing/halting stored procedure from ado.net Hi, I've strange problem with an application developed with VB.NET 2008/ADO.NET framework target 2.0 and SQL Server 2005. Sometimes a certain stored procedure wich normally executes in seconds, suddenly takes forever (15minutes plus). When I execute the stored procedure from within SQL Server Management Studio it always executes fast (42000+ records in 1 second), even when from ADO.NET it takes forever. When the slowdown appears, restarting the application does not help. When I do modify/execute in man.studio, the slowdown goes away, and application does it normal quick response. Activity monitor show no blocking other queries. The stored procedure is called with a command object and an dataadapter filling a dataset. When I break the application in visual studio, it breaks on the da.fill(ds) line. I cannot find any pattern in when the slowdown starts, sometime once a week, once a day or 3 weeks without a problem. Records added to the table are about 45 records per day (mean). Can anyone shed some light on this problem?? Tag: Querying a Runtime Dataset with LINQ Tag: 144990
  - 3
    - Open Source Typed DataSet Generator Drawing a blank, even googling some keywords and still gives me either too much or too little. Basically, anyone know of any custom open source typed dataset generators for use with the 3.5 framework? I am looking for a generator that exposes the column properties as public instead of internal/friend. (wish MS would just make their generator expose these as public, would make my life a little easier). Thanks, Mythran Tag: Querying a Runtime Dataset with LINQ Tag: 144979
  - 4
    - ADOMD client I have a webserver talking to a different server hosting SQL 2005. The webserver seems to need the ADOMD client on it.. Is this a seperate install? If so, is it free to install or is there licence issues? help is appreciated. Tag: Querying a Runtime Dataset with LINQ Tag: 144970
  - 5
    - SQL Coalesce in Linq syntax How would the following SQL Coalesce statement need to be written in Linq to SQL: SELECT COALESCE(LastName, '') + ' ' + COALESCE(FirstName, '') + ' ' + COALESCE(MiddleName, '') + ' ' + COALESCE(SuffixName, '') AS ClientName, ClientID FROM tblClient WHERE LastName LIKE @Letter + '%' ORDER BY ClientName Thanks, Dean Slindee Tag: Querying a Runtime Dataset with LINQ Tag: 144962
  - 6
    - First chance exceptions Hi When running my app in vs 2008 IDE I get the below messages in the Immediate Window repeatedly. A first chance exception of type 'System.NullReferenceException' occurred in MyApp.exe A first chance exception of type 'System.Runtime.InteropServices.InvalidComObjectException' occurred in MyApp.exe A first chance exception of type 'System.IO.FileNotFoundException' occurred in System.Drawing.dll A first chance exception of type 'System.ArgumentNullException' occurred in mscorlib.dll They don't crash the app but it seems the app slows downs when one of these errors occurs. What is the problem and how can I fix tit? Thanks Regards Tag: Querying a Runtime Dataset with LINQ Tag: 144958
  - 7
    - Datatable equivalent code with OleDbDataReader Hi I have below code which is written using a datatable dt. What is the equivalent code using a OleDbDataReader? For j = 0 To dt.Rows.Count - 1 Dim dataArr(dt.Columns.Count) As String For i = 0 To dt.Columns.Count - 1 dataArr(i) = dt.Rows(j)(i) Next Next Thanks Regards Tag: Querying a Runtime Dataset with LINQ Tag: 144954
  - 8
    - OleDbDataReader to datatable Hi Sorry, I am new to this. Is there a way to cerate a datatable from a OleDbDataReader? Thanks Regards Tag: Querying a Runtime Dataset with LINQ Tag: 144953
  - 9
    - error that occur in StoredProcedure it's cause exception or not? error that occur in StoredProcedure it's cause exception or not? and when I need to use with @@error? Tag: Querying a Runtime Dataset with LINQ Tag: 144952
  - 10
    - Tracking source of web service call Hi, I hope I'm posting this in the right group. I have a shared .net 1.1 web service that is accessed by many applications across multiple sites. I was wondering if there is an enterprise level tool that I could use to identify the source application (virtual directory of the originator, etc.). The IIS logs do not give me this information just the C-IP which is our web server, the CS-HOST which is our web services VIP, and the CS-Referrer which is blank. Any ideas? Tag: Querying a Runtime Dataset with LINQ Tag: 144948
  - 11
    - Designer generated code fails to compile I have a project whose default name space is Wearther and form in the project which is in this default namespace. I have also generated a dataset and adapters to access a table in a database. I am using as a datasource this dataset via the generated DatasetBindingSource. The problem is that the code the designed generates includes the lines this.wEATHERDETAILSTableAdapter = new Weather._WeatherDetailsDataSetTableAdapters.WEATHERDETAILSTableAdapter(); this._WeatherDetailsDataSet = new Weather._WeatherDetailsDataSet(); which explicitly specify the Weather namespace although the class is actually in this namespace and so the compilation fails unless I remove the namespace qualification by hand. How do I stop the designer from setting the namespace explicitly. Thanks Pat Tag: Querying a Runtime Dataset with LINQ Tag: 144939
  - 12
    - Slow app response Hi I have replaced an ms access app with its vb.net version at a client site. Now the clients keeps complaining about how slow the app response is. The complains they have are for example when app is minimised and then trying to maximise it after a while takes a while for app to get maximised. Also form painting of controls is slow and app is generally slow in terms of response to user clicks. I am using Infragistics controls and my feeling is that makes the app bit sluggish compared to the original controls shipped with vs 2008 but I need the Infragistics controls for their features. I have also ngen'd the app but surprisingly only the main app executable gets ngen'd and not any of the dependency dlls such as Infragistics dlls. Are there any tips to make app response better for user? Thanks Regards Tag: Querying a Runtime Dataset with LINQ Tag: 144937
  - 13
    - Inherited DataTable Serialization Problem in WCF Any help would be greatly appreciated. I am using WCF (3.0) to provide a services layer sitting on a server between a web server hosting ASP.NET 2.0 and SQL Server 2005. Some of these services provide a strongly typed inherited DataTable for the ASP.NET application. Below is a partial listing for one such DataTable. The code compiles successfully, and the service which returns this DataTable seems to start normally. A problem arises when using Add Service Reference in Visual Studio to generate a client class to communicate with the service. The error below the listing results when this generation is attempted. The most informative message in the error seems to be: "Schema type 'Components.DataStructures:EquipmentList' returned by CLR type 'Components.DataStructures.EquipmentList' is not found in the XmlSchemaSet." This says to me that in my class's GetXmlQualifiedName method, the schema for the EquipmentList class is not being added to XmlSchemaSet passed in by System.Runtime.Serialization.SchemaExporter.ExportXmlDataContract. To test this, I created a simple Windows form with a button which executed the following code: XmlSchemaSet xss = new XmlSchemaSet(); EquipmentList.GetXmlQualifiedName(xss); I checked the Count of xss.Schemas() before the static method on EquipmentList was called, and it was 0 as expected. I checked it after this method was executed and it was 1, also as expected. Further, 'Components.DataStructures:EquipmentList' did indeed exist in xss. In the quick watch window, the QualifiedName of the only schema is Components.DataStructures:EquipmentList. If it is there correctly when executed with this simple test code, I would expect the schema to be properly included in the XmlSchemaSet when called by System.Runtime.Serialization.SchemaExporter. Why am I getting this error? Am I misunderstanding the error, or is there something wrong in how I have tested my code? Any help to resolve this error is appreciated. INHERITED DATATABLE CODE [XmlSchemaProvider("GetXmlQualifiedName")] [Serializable] public class EquipmentList : DataTable, IXmlSerializable { private static string _tableName = "EquipmentList"; private static string _namespace = "Components.DataStructures"; private static XmlSchema _schema; . . . public EquipmentList():base(_tableName, _namespace) { Initialize(); } . . . private void Initialize() { _equipmentId.AllowDBNull = false; _name.AllowDBNull = false; _category.AllowDBNull = false; _type.AllowDBNull = false; base.Columns.Add(_equipmentId); base.Columns.Add(_name); base.Columns.Add(_category); base.Columns.Add(_type); if (_schema == null) { _schema = base.GetSchema(); } } . . . System.Xml.Schema.XmlSchema IXmlSerializable.GetSchema() { throw new System.NotImplementedException(); } void IXmlSerializable.ReadXml(System.Xml.XmlReader reader) { base.ReadXml(reader); } void IXmlSerializable.WriteXml(System.Xml.XmlWriter writer) { base.WriteXml(writer, XmlWriteMode.DiffGram); } public static XmlQualifiedName GetXmlQualifiedName(XmlSchemaSet xss) { if (_schema == null) { // Schema is set when an instance is created, so create // an instance if the schema is not yet set EquipmentList list = new EquipmentList(); } xss.Add(_schema); return new XmlQualifiedName(_tableName, _schema.TargetNamespace); } } SERVICE CLIENT GENERATION ERROR Error: Cannot obtain Metadata from net.tcp://localhost:52000/ComponentProviderListService/mex If this is a Windows (R) Communication Foundation service to which you have access, please check that you have enabled metadata publishing at the specified address. For help enabling metadata publishing, please refer to the MSDN documentation at http://go.microsoft.com/fwlink/?LinkId=65455. WS-Metadata Exchange Error URI: net.tcp://localhost:52000/ComponentProviderListService/mex Metadata contains a reference that cannot be resolved: 'net.tcp://localhost:52000/ComponentProviderListService/mex'. <?xml version="1.0" encoding="utf-16"?><Fault xmlns="http://www.w3.org/2003/05/soap-envelope"><Code><Value>Receiver</Value><Subcode><Value xmlns:a="http://schemas.microsoft.com/net/2005/12/windowscommunicationfoundation/dispatcher">a:InternalServiceFault</Value></Subcode></Code><Reason><Text xml:lang="en-US">An exception was thrown in a call to a WSDL export extension: System.ServiceModel.Description.DataContractSerializerOperationBehavior contract: http://tempuri.org/:IComponentProviderListService</Text></Reason><Detail xmlns:s="http://www.w3.org/2003/05/soap-envelope"><ExceptionDetail xmlns="http://schemas.datacontract.org/2004/07/System.ServiceModel" xmlns:i="http://www.w3.org/2001/XMLSchema-instance"><HelpLink i:nil="true"></HelpLink><InnerException><HelpLink i:nil="true"></HelpLink><InnerException i:nil="true"></InnerException><Message>Schema type 'Components.DataStructures:EquipmentList' returned by CLR type 'Components.DataStructures.EquipmentList' is not found in the XmlSchemaSet.</Message><StackTrace> at System.Runtime.Serialization.SchemaExporter.ExportXmlDataContract(XmlDataContract dataContract) at System.Runtime.Serialization.SchemaExporter.ExportDataContract(DataContract dataContract) at System.Runtime.Serialization.SchemaExporter.Export() at System.Runtime.Serialization.XsdDataContractExporter.Export(Type type) at System.ServiceModel.Description.MessageContractExporter.ExportType(Type type, String partName, String operationName, XmlSchemaType& xsdType) at System.ServiceModel.Description.DataContractSerializerMessageContractExporter.ExportBody(Int32 messageIndex, Object state) at System.ServiceModel.Description.MessageContractExporter.ExportMessage(Int32 messageIndex, Object state) at System.ServiceModel.Description.MessageContractExporter.ExportMessageContract() at System.ServiceModel.Description.DataContractSerializerOperationBehavior.System.ServiceModel.Description.IWsdlExportExtension.ExportContract(WsdlExporter exporter, WsdlContractConversionContext contractContext) at System.ServiceModel.Description.WsdlExporter.CallExtension(WsdlContractConversionContext contractContext, IWsdlExportExtension extension)</StackTrace><Type>System.Runtime.Serialization.InvalidDataContractException</Type></InnerException><Message>An exception was thrown in a call to a WSDL export extension: System.ServiceModel.Description.DataContractSerializerOperationBehavior contract: http://tempuri.org/:IComponentProviderListService</Message><StackTrace> at System.ServiceModel.Description.WsdlExporter.CallExtension(WsdlContractConversionContext contractContext, IWsdlExportExtension extension) at System.ServiceModel.Description.WsdlExporter.CallExportContract(WsdlContractConversionContext contractContext) at System.ServiceModel.Description.WsdlExporter.ExportContract(ContractDescription contract) at System.ServiceModel.Description.WsdlExporter.ExportEndpoint(ServiceEndpoint endpoint, XmlQualifiedName wsdlServiceQName) at System.ServiceModel.Description.WsdlExporter.ExportEndpoints(IEnumerable`1 endpoints, XmlQualifiedName wsdlServiceQName) at System.ServiceModel.Description.ServiceMetadataBehavior.MetadataExtensionInitializer.GenerateMetadata() at System.ServiceModel.Description.ServiceMetadataExtension.EnsureInitialized() at System.ServiceModel.Description.ServiceMetadataExtension.WSMexImpl.GatherMetadata(String dialect, String identifier) at System.ServiceModel.Description.ServiceMetadataExtension.WSMexImpl.Get(Message request) at SyncInvokeGet(Object , Object[] , Object[] ) at System.ServiceModel.Dispatcher.SyncMethodInvoker.Invoke(Object instance, Object[] inputs, Object[]& outputs) at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc& rpc) at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc& rpc) at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)</StackTrace><Type>System.InvalidOperationException</Type></ExceptionDetail></Detail></Fault> Please excuse me for crossposting this here and (yesterday) on the dotnet.xml group. I have not been able to find an MSDN Managed group for WCF specifically and am guessing about the most appropriate group to post this to. Tag: Querying a Runtime Dataset with LINQ Tag: 144935
  - 14
    - export to csv Hi Is there a way to export the records from a datareader into a csv file? Thanks Regards Tag: Querying a Runtime Dataset with LINQ Tag: 144933
  - 15
    - Calling a form in second project Hi Can I run a from in one project from a second project, both projects being in the same solution? Thanks Regards Tag: Querying a Runtime Dataset with LINQ Tag: 144930
  - 16
    - PerformanceCounterCategory.Create() takes 3 minutes to add a new category!! How come? What can cause this? PerformanceCounterCategory.Create() takes 3 minutes to add a new category!! How come? What can cause this? Tag: Querying a Runtime Dataset with LINQ Tag: 144929
  - 17
    - Problem binding dataset to several controls on a Winform Hi; I have a dataset containing two tables which are related the primary table is bound to a Nav control an two one grid view and the relationship of the second table is bound to a second gridview. I also have two textbox controls which I use to look up records in either table two, or table one. My problem is that if I do a lookup in table two it retrieves that record and displays it, but the relationship is lost, so the corresponding record in table one is not displayed in it's gridview. Also I lose my orginial navagation coordination between the first dataset and the two gridviews. Here is a little code that I use for the lookup and also a procedure that I thought would restore the original gridview behavior. LOOKUPS Private Sub ToolStripButton1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ToolStripButton1.Click ' Look up branch Try Me.Branch_CodesTableAdapter.LookUpBranch_Matches(Me.TCMS_TempDataSet1.Branch_Codes, ToolStripTextBox1.Text) Me.Branch_CodesBindingSource.DataSource = Me.TCMS_TempDataSet1.Branch_Codes Me.Branch_managerDataGridView.DataSource = Me.TCMS_TempDataSet1.branch_manager Catch ex As Exception MessageBox.Show(ex.Message) End Try End Sub REFRESHES Gridviews Private Sub RefreshData() Try Me.TCMS_States_DS.Clear() Me.StatesTableAdapter.Fill(Me.TCMS_States_DS.States) Me.TCMS_TempDataSet1.Clear() Me.Branch_CodesTableAdapter.Fill(Me.TCMS_TempDataSet1.Branch_Codes) Me.Branch_managerTableAdapter.Fill(Me.TCMS_TempDataSet1.branch_manager) ToolStripTextBox1.Text = "" ToolStripTextBox2.Text = "" Catch ex As System.Exception MessageBox.Show(ex.Message) End Try End Sub Thanks for any suggestions ! -- Gordon Tag: Querying a Runtime Dataset with LINQ Tag: 144928
  - 18
    - Should a LINQ DataContext be created for each query? As in these examples, referring to the first line of code in each set. Would a form-level only datacontext be wise? If a form did many Select queries against the same table, would one datacontext suffice for all the Select queries? Query: Dim dc As New dcAdminDataContext Dim query = From tblAdminAddressType In dc.tblAdminAddressTypes _ Order By tblAdminAddressType.AddressTypeID _ Select tblAdminAddressType Delete: Dim dc As New dcAdminDataContext Dim delete = From tblAdminAddressType In dc.tblAdminAddressTypes _ Where tblAdminAddressType.AddressTypeID = Trim(txtAddressTypeID.Text) _ And tblAdminAddressType.Guid = guid If delete.Count > 0 Then For Each tblAdminAddressType In delete dc.tblAdminAddressTypes.DeleteOnSubmit(tblAdminAddressType) Next dc.SubmitChanges(Data.Linq.ConflictMode.FailOnFirstConflict) Else Throw New Data.Linq.ChangeConflictException End If Insert: Dim dc As New dcAdminDataContext Dim insert As New tblAdminAddressType With insert .AddressTypeID = AddressTypeID .AddressTypeName = Trim(txtAddressTypeName.Text) .Inactive = CType(Trim(cboInactive.Text), Char) .InactiveDate = IIfNothingDate(txtInactiveDate.Text) .EffectiveDate = IIfNothingDate(txtEffectiveDate.Text) .AuditLog = AuditLog .Guid = newGuid End With dc.tblAdminAddressTypes.InsertOnSubmit(insert) dc.SubmitChanges(Data.Linq.ConflictMode.FailOnFirstConflict) Update: Dim dc As New dcAdminDataContext Dim update = From tblAdminAddressType In dc.tblAdminAddressTypes _ Where tblAdminAddressType.AddressTypeID = Trim(txtAddressTypeID.Text) _ And tblAdminAddressType.Guid = guid If update.Count > 0 Then For Each tblAdminAddressType In update With tblAdminAddressType .AddressTypeID = AddressTypeID .AddressTypeName = Trim(txtAddressTypeName.Text) .Inactive = CType(Trim(cboInactive.Text), Char) .InactiveDate = IIfNothingDate(txtInactiveDate.Text) .EffectiveDate = IIfNothingDate(txtEffectiveDate.Text) .AuditLog = AuditLog .Guid = newGuid End With Next dc.SubmitChanges(Data.Linq.ConflictMode.FailOnFirstConflict) Else Throw New Data.Linq.ChangeConflictException End If Tag: Querying a Runtime Dataset with LINQ Tag: 144927
  - 19
    - Hide data object property VS2005 pro The short question is this: How do I hide public properties of my class from binding in a datagrid for example. Setting <Browsable(false)> will not work since I have to bind to these properties in some win forms. In need the property available when binding, but not to display in grids. Here is the detail: I have custom data classes for my business objects. Amoungst the properties are other "nested" child objects like this: Class Invoice public property ID as Integer get ... set ... end property ... more properties public readonly property InvItems as InvoiceItems get ... end property end class Normally I would have a BindingSource bound to Invoice and then another BindingSource bound to Invoice.InvItems. All is ok so far, but when I load this object into a DataTable the InvItems object is included which I do not want. I can get rid of it by deleting the Column, but I would rather do it in the object itself using an attribute. I have tried to set the unwanted property with the attribute <Browsable(False)>, but then I cannot bind to it at runtime. So I need some other attribute or method to acomplish this. The only thing I can think of is a custom attribute. Any other ideas? Regards, Rick Tag: Querying a Runtime Dataset with LINQ Tag: 144922
  - 20
    - (oracle) problem with variable in 'in' condition Hi everybody ! I have a problem with a Select procedure in package. I have a condition like : select ..... from .... where blahblah in (myvariable).. 'myvariable' is like : 1001, 1002, 1003, .... I have an exception with the OracleDataAdapter : ORA-01002: fetch out of sequence do you have an idea ? Thanks by advance. Ju Tag: Querying a Runtime Dataset with LINQ Tag: 144919
  - 21
    - Varbinary col in datatable Using SQL Server 2005, Visual Studio 2005 (8.0.50727.762) Framework 2.0.50727 SP1 I have a varbinary column in my database. I am trying to set the DataColumn.DataType in the dataset designer to byte[] but it is not in the selection list. I tried changing it in the xxxxx.Designer.cs file but of course the changes were lost when the project was re-built. What is the solution? Can I code this.columnMissionStatusImage = new global::System.Data.DataColumn("MissionStatusImage", typeof(byte[]), null, global::System.Data.MappingType.Element); in the .cs file? If so, what event do I put it in? Tag: Querying a Runtime Dataset with LINQ Tag: 144915
  - 22
    - linqdatasource runtime connection string I want to set the connection string to use at runtime for my linqsql datacontext. I am using the dbml or mapper in Visual Studio. The way I created objects was by dragging objects from the server explorer onto the design surface. When I dragged the first object it made a connection string in my web.config called: XXX with integrated security. I want the datacontext to use connection YYY which I have in the web.config. If I change the Connection property in the dataContext object the next time I add something to the designer it forces me to change the connection string back to XXX. My connection strings in the web.config get changed by MsBuild for test and release. I am really worried that someone will make a change to the DataContext designer and the connection string will get set to XXX for use in Production. Is their a good way to work around this? Tag: Querying a Runtime Dataset with LINQ Tag: 144912
  - 23
    - How to to handle a set that had a row added and then deleted before Adapter Update? I have a scenario where I am processing a batch of changes to a table. The changes can result in an Insert or a Delete. So I Fill a DataSet with the table's current contents, then I process the changes, then call Update on my SqlAdapter. Psuedo Code: Fill(DataSet, MyTable) Foreach( Statement in UpdateCollection) { Foreach(Row in DataSet.Tables[MyTable].Rows) { if(Statement matches Row & !found) Row.Delete() found=true } if(!found) DataSet.Tables[0].Rows.Add(NewRowFromStatement) } Update(DataSet, MyTable) Unfortunately, there is a small chance that two records in the current batch of changes are related, basically one record will be the delete for one of the inserts in the update collection and this seems to cause a host of problems I cannot get arround. If I call Update, then since the Deleted row never had an original version the DeleteCommand can't find an original row to delete from the source table and throws an exception (Deleted 0 rows, expected 1). I had thought maybe if I found a row that was state Added and I needed to Delete it I could just call Remove, or AcceptChanges->Delete->Acceptchanges to cause the row to essentially disappear from the scope of the update. But this blows up the enumeration since it alters the Rows collection. I think my only option is to add a new column to my table MarkedForDelete and change the code to only Add and Update then make a seperate process to cull rows marked for delete asynchronously. Any tips? Thanks, Jason Tag: Querying a Runtime Dataset with LINQ Tag: 144911
  - 24
    - Re: Batch updates on generated TableAdapters throws Set the UpdatedRowSource property of your command to UpdateRowSource.None command.UpdatedRowSource = UpdateRowSource.None; Tag: Querying a Runtime Dataset with LINQ Tag: 144910
  - 25
    - SqlParamater where type=SqlDbType.VarChar allows a size of -1!!! I've just finished writing some unit tests to test some SqlParameter functions I created for a DAL helper class. I have included the base version of the method below. One of the tests I wrote is a boundary test and checks to make sure a size of -1 throw an 'ArgumentOutOfRange' exception. For some reason, it does not....however, anything less than -1 does. Does anyone know why? BTW: I'm using .Net 2.0 and Ado.NET public SqlParameter createStringParameter(string paramName, int size) { SqlParameter result = new SqlParameter(paramName, SqlDbType.VarChar); result.Size = size; result.Value = DBNull.Value; return result; } Cheers, Ed Tag: Querying a Runtime Dataset with LINQ Tag: 144907
- Next
  - 1
    - Anyone know of a Silverlight newsgroup? I am looking for a Silverlight newsgroup, I can't find one on news.microsoft.com. Thanks Brian K. Williams Tag: Querying a Runtime Dataset with LINQ Tag: 144903
  - 2
    - How to make CLR stored procedure generate comments in TSQL when it is deployed via visual studio? How to make CLR stored procedure generate comments in TSQL when it is deployed via visual studio? e.g. when i right click the project and hit deploy, i want some comments to appear in or around the SQL wrapper that calls the CLR function. Tag: Querying a Runtime Dataset with LINQ Tag: 144894
  - 3
    - Call Dispose on OleDbCommand? 1. Should you explicitly call Dispose on OleDb objects like OleDbCommand or OleDbConnection? 2. In VB.NET for the keyword USING (as in "Using cn As New OleDbConnection(...)...") Should you explicitly call the Close method on the OleDbConnection object or will the object be closed and disposed automatically once the Using block is exited? Thanks for your insights. Tag: Querying a Runtime Dataset with LINQ Tag: 144892
  - 4
    - Varbinary col in a DataTable Using SQL Server 2005, Visual Studio 2005 (8.0.50727.762) Framework 2.0.50727 SP1 I have a varbinary column in my database. I am trying to set the DataColumn.DataType in the dataset designer to byte[] but it is not in the selection list. I tried changing it in the xxxxx.Designer.cs file but of course the changes were lost when the project was re-built. What is the solution? Can I code this.columnMissionStatusImage = new global::System.Data.DataColumn("MissionStatusImage", typeof(byte[]), null, global::System.Data.MappingType.Element); in the .cs file? If so, what event do I put it in? Tag: Querying a Runtime Dataset with LINQ Tag: 144891
  - 5
    - OutOfMemoryException using .NewRow I am dealing with a very large amount of data add it to a dataset using DataTable.Rows.Add. When creating the new row using .NewRow I get an OutOfMemoryException at around row 4 million plus. I know that this is a very large number of rows, but I have 4 GB of Ram and the Task Manager shows that I am only using about 35% of system memory. Can someone help me understand why I am getting this error when apparently I am not running out of memory. Do I need to release any objects during this process. I am pretty much following what every example shows on using this code. The code can be seen below. Dim dtLatestDate As DateTime Dim dsData As New DataSet Dim dsScadaHistory As New DataSet1 Dim drScadaHistory, drLookup, drNameLookup() As DataRow Dim idxRows, idxColumns, iRowCount As Integer Dim dtScadaDateTime As DateTime Dim strName As String Dim keyObject(1), keyNameObject(0) As Object 'set up connections to the two SQL Server Dim conSurvalent As New SqlClient.SqlConnection(My.Settings.conSurvalent) Dim conSQL As New SqlClient.SqlConnection(My.Settings.conSQL) 'Set up commands and dataadapters Dim cmdGetLatestDate As New SqlClient.SqlCommand("SELECT MAX(DateTime) FROM ScadaHistory", conSQL) Dim daSurvalent As New SqlClient.SqlDataAdapter("SELECT * from ARCHIVE_QSE_Rev3 WHERE TIME > @TIME", conSurvalent) daSurvalent.SelectCommand.Parameters.Add(New System.Data.SqlClient.SqlParameter("@TIME", System.Data.SqlDbType.DateTime, 8, "TIME")) 'setup data adapter for the names pull Dim daNames As New SqlClient.SqlDataAdapter("SELECT Name, NameID FROM Names", conSQL) 'setup insert name into names table Dim cmdInsertName As New SqlClient.SqlCommand("INSERT INTO NAMES (Name) VALUES (@Name)", conSQL) cmdInsertName.Parameters.Add(New System.Data.SqlClient.SqlParameter("@Name", System.Data.SqlDbType.VarChar, 40, "Name")) 'load names table into dataset daNames.Fill(dsScadaHistory, "Names") Dim Array(2) As String 'get the latest date for SCADA data conSQL.Open() dtLatestDate =3D IIf(IsDBNull(cmdGetLatestDate.ExecuteScalar), Date.Now.AddYears(-20), cmdGetLatestDate.ExecuteScalar) conSQL.Close() 'get SCADA data to convert daSurvalent.SelectCommand.Parameters("@TIME").Value =3D dtLatestDate daSurvalent.Fill(dsData, "ScadaHistory") iRowCount =3D dsData.Tables(0).Rows.Count While (idxRows < iRowCount) 'get the date time dtScadaDateTime =3D dsData.Tables(0).Rows(idxRows).Item("TIME") 'initialize so that will skip TIME column idxColumns =3D 1 'loop through all columns for each datetime and insert a row for each match value/status pair While (idxColumns < dsData.Tables(0).Columns.Count) 'get column name (which is point name) strName =3D dsData.Tables(0).Columns(idxColumns).ColumnName 'get NameID from foreign table keyNameObject(0) =3D strName drNameLookup =3D dsScadaHistory.Tables("Names").Select(String.Format("Name =3D '{0}'", keyNameObject(0))) 'if the name does not exist then insert the name into the table, which will write back to the dataset If (drNameLookup.Length =3D 0) Then conSQL.Open() cmdInsertName.Parameters("@Name").Value =3D strName cmdInsertName.ExecuteNonQuery() 'reload dataset with names after insert daNames.Fill(dsScadaHistory, "Names") conSQL.Close() 'get NameID from foreign table keyNameObject(0) =3D strName drNameLookup =3D dsScadaHistory.Tables("Names").Select(String.Format("Name =3D '{0}'", keyNameObject(0))) End If 'create SCADA history record with datetime and source name **************RIGHT HERE IS WHERE I GET THE ERROR**************************** drScadaHistory =3D dsScadaHistory.Tables("ScadaHistory").NewRow 'add datetime to row drScadaHistory("DateTime") =3D dtScadaDateTime 'add name to row drScadaHistory("NameID") =3D drNameLookup(0)("NameID") 'add value to row drScadaHistory("Value") =3D dsData.Tables(0).Rows(idxRows).Item(idxColumns) 'add status to row drScadaHistory("Status") =3D dsData.Tables(0).Rows(idxRows).Item(idxColumns + 1) 'add datarow to dataset dsScadaHistory.Tables("ScadaHistory").Rows.Add(drScadaHistory) drScadaHistory.AcceptChanges() 'increment column idxColumns +=3D 2 End While 'increment index idxRows +=3D 1 End While *****************************THIS IS THE ERROR**************************** System.OutOfMemoryException was unhandled Message=3D"Exception of type 'System.OutOfMemoryException' was thrown." Source=3D"System.Data" StackTrace: at System.Data.Common.DoubleStorage.SetCapacity(Int32 capacity) at System.Data.RecordManager.set_RecordCapacity(Int32 value) at System.Data.RecordManager.GrowRecordCapacity() at System.Data.RecordManager.NewRecordBase() at System.Data.DataTable.NewRecord(Int32 sourceRecord) at System.Data.DataTable.NewRow(Int32 record) at System.Data.DataTable.NewRow() at DBOSchema.Form1.Form1_Load(Object sender, EventArgs e) in C:\Documents and Settings\All Users\Documents \Visual Studio 2008\Projects\DBOSchema\DBOSchema\Form1.vb:line 74 at System.EventHandler.Invoke(Object sender, EventArgs e) at System.Windows.Forms.Form.OnLoad(EventArgs e) at System.Windows.Forms.Form.OnCreateControl() at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible) at System.Windows.Forms.Control.CreateControl() at System.Windows.Forms.Control.WmShowWindow(Message& m) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ScrollableControl.WndProc(Message& m) at System.Windows.Forms.ContainerControl.WndProc(Message& m) at System.Windows.Forms.Form.WmShowWindow(Message& m) at System.Windows.Forms.Form.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) at System.Windows.Forms.SafeNativeMethods.ShowWindow(HandleRef hWnd, Int32 nCmdShow) at System.Windows.Forms.Control.SetVisibleCore(Boolean value) at System.Windows.Forms.Form.SetVisibleCore(Boolean value) at System.Windows.Forms.Control.set_Visible(Boolean value) at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context) at System.Windows.Forms.Application.Run(ApplicationContext context) at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun= =AD () at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApp= =AD licationModel() at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(S= =AD tring[] commandLine) at DBOSchema.My.MyApplication.Main(String[] Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81 at System.AppDomain._nExecuteAssembly(Assembly assembly, String[] args) at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args) at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly() at System.Threading.ThreadHelper.ThreadStart_Context(Object state) at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.ThreadHelper.ThreadStart() InnerException: Tag: Querying a Runtime Dataset with LINQ Tag: 144888
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    - How to fill a listview from LINQ query Currently using a legacy Winform listview, that is filled by a function from datatable(0) in a dataset. This works fine as the datatable has column headers and data rows that correspond to listview headers and listview rows. Would like to use Linq to SQL to populate the same legacy WinForm listview. The code below retrieves the IOrderedQuery object correctly: Dim dc As New dcAdminDataContext Dim query = From tblAdminAddressType In dc.tblAdminAddressTypes _ Order By tblAdminAddressType.AddressTypeID gvwAdminData.DataSource = query The last statement fills a datagridview thru the .DataSource property. Since, a listview has no .DataSource property, I am at an impasse as to how to convert query to a datatable, or ? I do not want to specify the data column names within each query nor declare a class for the query structure. Any ideas? Thanks in advance, Dean S Tag: Querying a Runtime Dataset with LINQ Tag: 144885
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    - Microsoft architect to discuss LINQ, ADO.NET Entity Framework & Data The program for DataServices World (June 24, New York City) has been announced. The conference includes a distinguished lineup of speakers from BEA, Blue Cross/Blue Shield, IBM, iWay Software, Microsoft, Morgan Stanley and Sun Microsystems. Mike Pizzo is the lead architect for Microsoft's data access and data programmability initiatives. He's been responsible for developing the ODBC Cursor Library, OLE DB, ADO and ADO.NET. At DataServices World, Mike Pizzo will speak about LINQ, ADO.NET Entity Framework and ADO.NET Data Services. He will also participate in a Data Access and Data Services Workshop with Dr. Michael Carey (BEA Systems) and Dr. Carlo Innocenti (DataDirect Technologies). http://dataservicesworld.sys-con.com/general/session0608.htm "LINQ and ADO.NET Entity Framework and Data Services for the Web" When: June 24, 2008 (2:00 - 2:50 pm) Where: Roosevelt Hotel, 45th and Madison Avenue, New York City "The ADO.NET Entity Framework raises the level of abstraction for data programming. It is the evolution of ADO.NET that allows developers to program in terms of the standard ADO.NET abstraction or in terms of persistent objects (ORM) and is built upon the standard ADO.NET Provider model. The Entity Framework introduces a set of services around the Entity Data Model (EDM) (a medium for defining domain models for an application). The goal of ADO.NET Data Services is to enable applications to expose data as a REST-based data service that can be consumed by Web clients within a corporate network and across the Internet. The data service is reachable over HTTP, and URIs are used to identify the various pieces of information available through the service. Interactions with the data service happens in terms of HTTP verbs, such as GET, POST, PUT, and DELETE, and the data exchanged in those interactions is represented in simple formats, such as AtomPub and JavaScript Object Notation (JSON). " Tag: Querying a Runtime Dataset with LINQ Tag: 144884
  - 8
    - Add column using Dataset Designer => hosed project Context: VS2008 SQL Server Compact 3.5 database Problem: I used the Dataset Designer to add a column to a table (right click on table in designer, Add->Column). How do I update the database to correspond with this change? I tried locating the database in my Server Explorer and adding the identical column by hand using the Table Properties. Run the project and try to stuff some data in the newly modifed table...all original columns get data but the new column only gets NULLs. Try to use "Configure DataSet with Wizard" from Data Sources tab...get warning that "The selected dataset contains objects that can only be viewed with the Dataset Designer." Which I don't understand because I made what seems a trivial modification to a table. It seems there is no correspondence between the new column in the database and the new column in the dataset. If I access the new column's DataColumn properties in DataSet Designer, the entry for the "Source" property is empty, and the dropdown selector only sees the original columns in the table, not the new one. Tag: Querying a Runtime Dataset with LINQ Tag: 144880
  - 9
    - Databinding to a TextBox in WPF Is it possible to bind an IList<string> to a TextBox and show the first value and use Buttons to navigate forward and backwards through the data? I have a window with just 3 controls: 1. Previous Button 2. TextBox 3. Next button My goal is to bind a collection of names to the TextBox and be able to cyle through them with the two navigation buttons. Here's the code behind I have in place for a XAML (WPF) window: ------------------------------------ private ListCollectionView view; public DataNavigator() { InitializeComponent(); ICollection<string> names = new Data().GetJustNames(); DataContext = names; view = (ListCollectionView) CollectionViewSource.GetDefaultView(DataContext); view.CurrentChanged += view_CurrentChanged; } void view_CurrentChanged(object sender, System.EventArgs e) { btnPrevious.IsEnabled = (view.CurrentPosition > 0); btnNext.IsEnabled = (view.CurrentPosition < view.Count-1); } private void btnNext_Click(object sender, RoutedEventArgs e) { view.MoveCurrentToNext(); } private void btnPrevious_Click(object sender, RoutedEventArgs e) { view.MoveCurrentToPrevious(); } --------------------------------------------------------------------------------------------- Now I'm pretty sure the navigation is working because the buttons become disabled correctly. My only question is how do I set the binding to the TextBox.Text property in XAML? <TextBox Margin="139,56.5,169,65.5" Name="tbName" Text="{Binding Path=?}"/> I'm not sure what the Path should be. I don't think I have to set the source because the TextBox is within the DataContext right? Thanks for any insight you might be able to provide! Mark Moeykens Tag: Querying a Runtime Dataset with LINQ Tag: 144878
  - 10
    - Varbinary column in a DataTable Using SQL Server 2005, Visual Studio 2005 (8.0.50727.762) Framework 2.0.50727 SP1 I have a varbinary column in my database. I am trying to set the DataColumn.DataType in the dataset designer to byte[] but it is not in the selection list. I tried changing it in the xxxxx.Designer.cs file but of course the changes were lost when the project was re-built. What is the solution? Can I code this.columnMissionStatusImage = new global::System.Data.DataColumn("MissionStatusImage", typeof(byte[]), null, global::System.Data.MappingType.Element); in the .cs file? If so, what event do I put it in? Tag: Querying a Runtime Dataset with LINQ Tag: 144876
  - 11
    - LINQ derived NullReference NullReferenceException when Inserting from derived class STEPS to reproduce: 1- Define a database table Foo(ID:int(PK), Name:nchar(10)) 2- Create an application project. 3- Define a LINQ to SQL model and add entity 'Foo' from the created table. 4- Add a new class 'FooEx' to the project, inherit it from 'Foo', 5. Add an extra property of type 'int' named 'ExtraInfo' to FooEx. 6. Add a statically initialized DataContext to FooEx 7. Create a public method Insert in FooEx 8. In the insert method put db.Foos.InsertOnSubmit(this); where db is the DataContext instance for the class 9. In the insert method put db.SubmitChanges; where db is the DataContext instance for the class 10. Enter and execute the following code in 'Main' or button click or such. FooEx f = new FooEx(); f.ID = 1; f.Name = "OhOh"; f.Insert(); Actual ResultsUpon executing the described project, the following exception is thrown when trying to attach the record: NullReferenceException: Message: "Object reference not set to an instance of an object." Occurs on â?? InsertOnSubmit. update fails similarly Note: linq should have its own newsgroup- currently it is being entered in C#, Framework, and this one Tag: Querying a Runtime Dataset with LINQ Tag: 144870
  - 12
    - How to Update an existing schema on a typed dataset I need to do what seemes a simple task, but i am stuck. I have a column in my database i need to change from 7 chars to 10 chars. I have a number of strongly typed datasets in my system that use this table. I attempted to edit the xsd file in the designer and changed the 7 to a 10. But the underlaying class file did not get updated. When i searched for the column i need to change it still was set to 7. Then I attempted to run the "Table Adapter Configuration Widard". This actually broke the application and it would not compile. I then noticed that duplicate colmns appeared in the table in the dataset. For example there was ProjectId and ProjectId1. ProjectId1 did not exist before. I hope i am missing something simple here. I did change the code generated files to widen the columns in question and the app seemed to work ok, but i am sure this is not the prefered way to go, any help would be appreciated. Tag: Querying a Runtime Dataset with LINQ Tag: 144868
  - 13
    - Replacement for dataadapter Hi Experts, I am having new problem again. This is regarding SqlDataAdapter fill method performance. Even though its discussed several times my problem is little different. I had migrated one VB6 application to .Net 2.0. In VB6 application they were using RecordSet. Like, ---------------------- Dim rs As New ADODB.Recordset cnn.Open GetDataProvider() rs.Open cSQLUpdateTimeSeries, cnn, adOpenDynamic, adLockPessimistic ---------------------- Later, RecordSet get updated, Like ---------------------- For k = LBound(data, 1) To UBound(data, 1) rs.AddNew rs![sessionID] = session . . . rs![ReportingDate] = Dates(LBound(Dates, 1), k) . . Next rs.Update End If Next rs.Close cnn.Close ---------------------- When I migrated the code to ASP.Net 2.0, I used SqlDataAdapter. ---------------------- adap = New SqlDataAdapter(cSQLUpdateRequest, cnn) Dim cmdBuilder As SqlCommandBuilder = New SqlCommandBuilder(adap) adap.InsertCommand = cmdBuilder.GetInsertCommand() adap.Fill(dt) ---------------------- Here in between some calculation is happening and need to update in database. Dataset is updated like, ---------------------- For k = LBound(data, 1) To UBound(data, 1) Dim dr As DataRow = dt.NewRow() dr("sessionID") = session . . . dr("ReportingDate") = Dates(LBound(Dates, 1), k) . . dt.Rows.Add(dr) Next adap.Update(dt) ---------------------- Here my problem is <b> adap.Fill(dt) </b> is extemly slow and Is there any different approach for the above scenario to update the database (otherthan using adapter) ? Thank you Sriharsha Karagodu Tag: Querying a Runtime Dataset with LINQ Tag: 144867
  - 14
    - Databinding to a listview Hi, I'm trying to populate a list box using a dataset. The data set is tested fine to have data in it but when I run the app, the listbox does not get populated. Below is what I'm doing: Class1 myclass = new Class1(); myclass.Server = "LAPTOP"; myclass.DB = "Northwind"; DataSet ds = myclass.ReturnDS(); ListBox1.DataSource = ds.Tables[0]; ListBox1.DataTextField = "CustomerID"; ListBox1.DataBind(); // works ok, returns field so Dataset contains data Page.Response.Write(ds.Tables[0].Rows[0][0].ToString(); Why doesn't this work? Many thanks for any ideas in advance Ant Tag: Querying a Runtime Dataset with LINQ Tag: 144866
  - 15
    - DataContext - how to use Hi, I'm using LINQ for the first time in a "full" projekt and need some help on how to manage the datacontext. When having one function calling other functions doing LINQ work (select and or update) should I pass the datacontext along as a parameter (ei create one and use that), og should I let functions create (and dispose) there own datacontext? Do you have any advise about using a static global datacontext? Thanks Tag: Querying a Runtime Dataset with LINQ Tag: 144863
  - 16
    - Q: dynamically created databound controls persist but static controls I am running into a case where I am databinding a control (dropdown, checkboxlist, etc) to a datatable, caching the datatable in session, and on postback rebind the control. After postback the control loses its value. However if I try this with a dynamically created control, it maintains state just fine. (I would think it would be the other way around.) You can cut/paste my aspx and codebehind into your project from here: http://www.geocities.com/usenet_daughter/databind_persist_issue.htm How would you get the static control (CheckBoxList1) to maintain state after postback? I am curious why this is happening. Thanks Tag: Querying a Runtime Dataset with LINQ Tag: 144860
  - 17
    - Where to: Questions About EDM and CSDL We are about to start serious design on a new app here. I would like to use the Entity Framework stuff that's new in Framework 3.5 and since it's not even officially released yet, I'm sure to have some questions. So my question is "microsoft.public.dotnet.framework.adonet" the best group to ask questions about EDM and CSDL or is there a more appropriate place to do so? Writing the schemas by hand doesn't look all that appealing but it's still light-years better than writing a million SQL stored procedures. Our userbase is relatively small but they want the app ASAP, so I'm less worried about any potential loss of performance by eliminating SQL stored procedures and more motivated by reduced development time and lower maintenance requirements. Tag: Querying a Runtime Dataset with LINQ Tag: 144857
  - 18
    - How to read sequentially from a random point in a large Xml File. Hello Have a huge XML file with multitudes of "LogEntry" nodes / text lines. A small sample of this xml/text content is below. The file could be anywhere between 200 to 2000 MB. My questions comes in two parts. (A) I would like a solution (or ideas for it), in C#, -- to randomly access a really huge xml file, and to sequentially read only the "memory permiting" number of nodes into memory, from a place randomly selected in the huge file. The application otherwise returns an out of memory error or gets very slow, if i try to load the entire file, because the user like to "scroll" through the file, viewing different parts. Like when scrolling through a huge Word document. How is this (best) done? (B) What is, and/or how would i estimate, the max amount of xml or text from the file that the application can have in it's memory? The application is both a web applicatin and a windows standalone. On a 32bit machine with 2GB Ram, the virual memory is 2GB, which gives an answer. But i have a Java app that goes in a unhandled heap error already when loading xml from a 200MB size file. Any ideas, solutions, or links concerning the above (especially (A))? One avenue is to try to base a sequential reader on a random access stream. I tried this idea. I based the XmlTextReader (for seqeuntial read) on the FileStream (for randon access), but this didnt work. There is some test code at the bottom of this email that shows some of this. I used the FileStream for random access via the FileStream.Seek(..) method. But the XmlTextReader.Read() didn't start reading from the new position. The following: FileStream.Seek(<Random NewPosition>, SeekOrigin.Begin); FileStream.Read(); would read from a the new position, but it didnt effect the positioning of XmlTextReader.Read(). Even though XmlTextReader is based on the same FileStream. It caused though the last read of the XmlTextReader to validate the xml erroneously (when the xml was actually ok). An alternative is to base a StreamReader on a FileStream. The StreamReader.BaseStream is available for random access, and the StreamReader is there for sequential read. But i think the same problem is there, as when basing the XmlTextReader on the FileStream. As a side thought to the problem, - it could be more easily solved if MicroSoft offered an indexing mechanism (for application purposes) on NTSF files. But this isn't the case. Or if i could load the huge file into a database table, but the requirement is only to use xml files (or flat files), so this isn't an option. This question involves several "technologies". So i am posting it on several newsgroups. Here's a sample of the XML: Each "LogEntry" node is viewed as line of text in a GridView controller. <Logs AtrA="AllTheLogs"> <Log AtrA="log1" AtrB="Machine nr 1"> <LogEntry AtrA="name1" AtrB="time" AtrC="location" /> <LogEntry AtrA="name2" AtrB="time" AtrC="location" /> <LogEntry AtrA="name3" AtrB="time" AtrC="location" /> <LogEntry AtrA="name4" AtrB="time" AtrC="location" /> </Log> <Log AtrA="log2" AtrB="Machine nr 1"> <LogEntry AtrA="name5" AtrB="time" AtrC="location" /> <LogEntry AtrA="name6" AtrB="time" AtrC="location" /> </Log> </Logs> Some test code using XmlTextReader(FileStream) based on a file with the above xml. I used the VS debugger to look into the variables. System.IO.FileStream fs = null; int i = 0; long[] bookMarks = new long[4000]; String[] linesOfText = new String[4000]; byte[] aBuffer = new byte[1000]; char[] charBuffer = new char[1000]; try { fs = new FileStream("c:\\aXMLfile.xml", FileMode.OpenOrCreate); System.Xml.XmlTextReader reader = new XmlTextReader(fs); long lngthOfFS = fs.Length; Boolean a = false; while (reader.Read()) { bookMarks[i] = fs.Position; StreamReader sr = new StreamReader(fs); if (i == 2) { fs.Read(aBuffer, 0, aBuffer.Length); fs.Position = 0; fs.Read(aBuffer, 0, aBuffer.Length); for (int g = 0; g < aBuffer.Length; g++) { charBuffer[g] = (char)aBuffer[g]; } } linesOfText[i] = "Attribute count: " + reader.AttributeCount + ", NodeType: " + reader.NodeType + ", Name: " + reader.Name + ", value: " + reader.Value; a = reader.HasAttributes; if (reader.HasAttributes) { for (int ii = 0; ii < reader.AttributeCount; ii ++) { reader.MoveToAttribute(ii); linesOfText[i] = linesOfText[i] + "Attribute " + ii.ToString() + ":" + ", Name: " + reader.Name + ", value: " + reader.Value; } } i++; } } catch(Exception e) { String message = e.ToString(); } finally { fs.Unlock(0, fs.Length); } Other references: Efficient Techniques for Modifying Large XML Files http://msdn2.microsoft.com/en-us/library/aa302289.aspx XML Reader with Bookmarks http://msdn2.microsoft.com/en-us/library/aa302292.aspx The Best of Both Worlds: Combining XPath with the XmlReader http://msdn2.microsoft.com/en-us/library/ms950778.aspx Comments to references: Helena Kupkova developed a XmlBookmarkReader class (based on XmlReader). But when XmlBookmarkReader sets a bookmark on a read node, it caches it and the following node, to be able to "replay" the bookmark when it is needed. On huge files, an early bookmark will cache the xml content of the file until the applicaiton runs out of memory. Dare Obasanjo XPathReader doesnt avoid a sequential read of the file, testing for each read, for a match for one or more xpaths. For a new XPath, the code would have to seqential reading from the start of the file. -- Regards, Paul Tag: Querying a Runtime Dataset with LINQ Tag: 144856
  - 19
    - Question to the generals in this newsgroup including MSFT's Is this a FrameWork.ADONET or a LINQ newsgroup? As I see so many non LINQ to ADONET questions answered at the moment. Cor Tag: Querying a Runtime Dataset with LINQ Tag: 144843
  - 20
    - Reading a text field How do I get the data out of an MS-SQL Text field efficiently A simple "SELECT [FieldName] FROM [Table]" unfortunately returns a truncated version of the fields contents ( which actually contains an entire book ). I know that your not supposed to do a simple select, but my Google-Fu is weak and I dont know what words to search for. Can anyone supply some hints? Thanks Tag: Querying a Runtime Dataset with LINQ Tag: 144836
  - 21
    - SQL 2005 Error connecting to SQL2000 Hi, I'm connecting to an SQL2000 Server, it runs a very slow SP that takes around two minutes. I've set the command & connection timeout to handle this. It used to work fine but now I get a seemingly unrelated error. I can connect remotely to do simple queries & LINQ queries but the SP doesn't run. Any ideas would be gratefully appreciated Below is the error message: "An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)" Tag: Querying a Runtime Dataset with LINQ Tag: 144830
  - 22
    - Linq SubmitChanges and DataLoadOptions I have some code that has a DataLoadOption to load Master/Detail records. When I update the Master table, the object gets returned but the Details records are not loaded. Is their a work around for this? using (MyDataContext dc = new MyDataContext()) { DataLoadOptions lo = new DataLoadOptions(); lo.LoadWith<Job>(s => s.JobSections); var query = from obj in dc.Jobs where obj.JobID == 1 select obj; job = query.Single(); //yep job object has detail section data dc.SubmitChanges(); //nope job does not have detail section data. } Tag: Querying a Runtime Dataset with LINQ Tag: 144825
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    - linq combined query I tried to make some complex linq queries easier to read by pulling some of the queries out. This works fine: var qAllJobDescriptions = from j in dc.Jobs select j; var qAllOracleJobCodes = from o in dc.OracleJobCodes select o.JOBCODE; GridView_Ex3.DataSource = from j in qAllJobDescriptions where !(qAllOracleJobCodes).Contains(j.OracleJobCode) select j; This works fine: var qActiveJobDescriptions = from j in dc.Jobs where DateTime.Today >= j.StartDate && (j.EndDate == null || (DateTime.Today < j.EndDate.Value.AddDays(1))) select j; var qActiveOracleJobCodes =""; GridView_Ex2.DataSource = (from j in qActiveJobDescriptions where !(from o in dc.OracleJobCodes where DateTime.Today >= o.DATEFROM && (o.DATETO == null || (DateTime.Today < o.DATETO.Value.AddDays(1))) select o.JOBCODE).Contains(j.OracleJobCode) select new { j.OracleJobCode }) This blows up when I move the where !(....).Contains into its own query. Seems odd because I did a similar thing in the first example. : var qActiveJobDescriptions = from j in dc.Jobs where DateTime.Today >= j.StartDate && (j.EndDate == null || (DateTime.Today < j.EndDate.Value.AddDays(1))) select j; var qActiveOracleJobCodes =from o in dc.OracleJobCodes where DateTime.Today >= o.DATEFROM && (o.DATETO == null || (DateTime.Today < o.DATETO.Value.AddDays(1))) select o.JOBCODE; GridView_Ex2.DataSource = (from j in qActiveJobDescriptions where !(qActiveOracleJobCodes).Contains(j.OracleJobCode) select new { j.OracleJobCode }) ((System.Exception)((new System.Linq.SystemCore_EnumerableDebugView<<string>>(((System.Data.Linq.DataQuery<<string>>)(GridView_Ex2.DataSource)))).Items)).StackTrace at System.Data.Linq.SqlClient.SqlFactory.Member(SqlExpression expr, MemberInfo member) at System.Data.Linq.SqlClient.QueryConverter.VisitMemberAccess(MemberExpression ma) at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node) at System.Data.Linq.SqlClient.QueryConverter.VisitExpression(Expression exp) at System.Data.Linq.SqlClient.QueryConverter.VisitCast(UnaryExpression c) at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node) at System.Data.Linq.SqlClient.QueryConverter.VisitExpression(Expression exp) at System.Data.Linq.SqlClient.QueryConverter.VisitBinary(BinaryExpression b) at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node) at System.Data.Linq.SqlClient.QueryConverter.VisitExpression(Expression exp) at System.Data.Linq.SqlClient.QueryConverter.VisitBinary(BinaryExpression b) at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node) at System.Data.Linq.SqlClient.QueryConverter.VisitExpression(Expression exp) at System.Data.Linq.SqlClient.QueryConverter.VisitWhere(Expression sequence, LambdaExpression predicate) at System.Data.Linq.SqlClient.QueryConverter.VisitSequenceOperatorCall(MethodCallExpression mc) at System.Data.Linq.SqlClient.QueryConverter.VisitMethodCall(MethodCallExpression mc) at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node) at System.Data.Linq.SqlClient.QueryConverter.VisitSelect(Expression sequence, LambdaExpression selector) at System.Data.Linq.SqlClient.QueryConverter.VisitSequenceOperatorCall(MethodCallExpression mc) at System.Data.Linq.SqlClient.QueryConverter.VisitMethodCall(MethodCallExpression mc) at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node) at System.Data.Linq.SqlClient.QueryConverter.VisitContains(Expression sequence, Expression value) at System.Data.Linq.SqlClient.QueryConverter.VisitSequenceOperatorCall(MethodCallExpression mc) at System.Data.Linq.SqlClient.QueryConverter.VisitMethodCall(MethodCallExpression mc) at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node) at System.Data.Linq.SqlClient.QueryConverter.VisitExpression(Expression exp) at System.Data.Linq.SqlClient.QueryConverter.VisitUnary(UnaryExpression u) at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node) at System.Data.Linq.SqlClient.QueryConverter.VisitExpression(Expression exp) at System.Data.Linq.SqlClient.QueryConverter.VisitWhere(Expression sequence, LambdaExpression predicate) at System.Data.Linq.SqlClient.QueryConverter.VisitSequenceOperatorCall(MethodCallExpression mc) at System.Data.Linq.SqlClient.QueryConverter.VisitMethodCall(MethodCallExpression mc) at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node) at System.Data.Linq.SqlClient.QueryConverter.VisitSelect(Expression sequence, LambdaExpression selector) at System.Data.Linq.SqlClient.QueryConverter.VisitSequenceOperatorCall(MethodCallExpression mc) at System.Data.Linq.SqlClient.QueryConverter.VisitMethodCall(MethodCallExpression mc) at System.Data.Linq.SqlClient.QueryConverter.VisitInner(Expression node) at System.Data.Linq.SqlClient.QueryConverter.ConvertOuter(Expression node) at System.Data.Linq.SqlClient.SqlProvider.BuildQuery(Expression query, SqlNodeAnnotations annotations) at System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execute(Expression query) at System.Data.Linq.DataQuery`1.System.Collections.Generic.IEnumerable<T>.GetEnumerator() at System.Linq.SystemCore_EnumerableDebugView`1.get_Items() Tag: Querying a Runtime Dataset with LINQ Tag: 144823
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    - Error in field binding when using same table for combobox drop down and lookup Hi I have a sample vs 2008 winform project here; http://www.infovis.biz/TestEMS-vs2800.zip . Please extract it in C:\ folder so the project ends up in C:\Test EMS folder. Please run the project and you will see a data entry form. Use the buttons in the form's bottom area to scroll through the records. Everything works fine. You can even change text in fields and moving away from record will save it. Now go back into project and uncomment line 196 in frmStaff.vb ie Me.txtRate.Text = CStr(DLookup("[Rate]", "[Rates]", "[Rate ID] = """ & txtRateID.Text & """")) Now run the project and scroll through records. Soon you will see that information stops appearing in fields. The purpose of above line is that when user selects a Rate ID from the combobox drop down, the system looks up the corresponding rate amount and fills the Rate field with it. So my question is, why is this lookup causing this problem and what is the correct way to lookup a value and assign it to a bound field without causing this problem? Thanks Regards Tag: Querying a Runtime Dataset with LINQ Tag: 144822
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    - Update not working I'm developing a Web App in C#. The following method executes without exceptions but the database does not get changed. The data is changed in the record[0] at the point prior to executing the " adapter.Update(record);" instruction. Is there something else I should be doing to insure the update to take effect??? Thanks, Neil protected void UpdateUserFields(String id, String field, String value) { //***********************************************************// ***** Make connection, process request, break connection //*********************************************************** using (OdbcConnection connection = new OdbcConnection(ConnectionBuilder().ConnectionString)) { // ***** Make connection and get dataRows ***** String sql = "select * from Register where Id='" + id + "'"; OdbcDataAdapter adapter = new OdbcDataAdapter(sql, connection); DataSet dataSet = new DataSet(); try { connection.Open(); adapter.Fill(dataSet, "Register"); } catch (Exception ex) { Console.WriteLine(ex.Message); } DataRow[] record = dataSet.Tables["Register"].Select(); if (record.Count() == 0) return; //****** Process update request ****** // Update the cpu id list in the user's registation record if (field=="CpuId") record[0]["CpuId"]=value; //****** Update the data base with changes ****** // Mark the changes for updating record[0].AcceptChanges(); // Update the changes adapter.Update(record); } } Tag: Querying a Runtime Dataset with LINQ Tag: 144817

Hi,
Can you query a run time Dataset with LINQ or must the Dataset be strongly
typed?
If not, how can this be simply accomplished?

Many thanks for any ideas on this

Ant

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Re: Querying a Runtime Dataset with LINQ by Cor

Cor
Wed Apr 16 12:43:32 CDT 2008

Ant,

A DataSet is a collection of DataTables and Relations
A DataTable is a collection of DataRows and DataColumns
A DataRow is a collection of Items.

(All returned as referenced objects)

Why do you think that you cannot use Linq with collections?

Cor

"Ant" <Ant@discussions.microsoft.com> schreef in bericht
news:CE4B364B-FAD6-47DE-B3BC-AC018C4D4A75@microsoft.com...
> Hi,
> Can you query a run time Dataset with LINQ or must the Dataset be strongly
> typed?
> If not, how can this be simply accomplished?
>
> Many thanks for any ideas on this
>
> Ant

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