RecordStateChanged Object reference not set to an instance

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  - 1
    - Updating in memory datatable efficiently. Hello, I have an asp.net app . I load a huge table from database in a datatable object which is cached. The source table is modified once an hour. I want my "in memory" table to reflect these changes without reloading everything.( In fact , only a few rows are added , substracted to the table). How do i best update my "in memory" table without reloading the whole source table. That should be far more efficient then having to pull the entire table again. Many thanks JB Tag: RecordStateChanged Object reference not set to an instance Tag: 109822
  - 2
    - Fill DataSet tables from one SPROC Hello, I have a Typed DataSet added to my VS.net Project. This DataSet has two = tables I'm interested in filling. I'd like to know if it is possible to = fill both tables from one SqlDataAdapter.Fill() call. My stored = procedure returns two resultsets. How would map the resultsets returned = from the sproc to the correct tables in the DataSet? Thanks, --Michael Tag: RecordStateChanged Object reference not set to an instance Tag: 109820
  - 3
    - datasource designer problem I have VS.NET 2005 beta2... when I select the Configure Dataset with wizard menu from datasources window I got this error : "An Item with the same key has already been added." what's the problem here??? Tag: RecordStateChanged Object reference not set to an instance Tag: 109816
  - 4
    - Newbee question. Hello, I'm wondering about how to accomplish an apparent simple thing. I read from a cached dataset in an asp.net application cache as shown below: // Set a filter on the view of the Calls table. dsBoth.Tables["Calls"].DefaultView.RowFilter = "ContactID=" + drpContacts.SelectedItem.Value.ToString(); // Bind to the data grid. grdCalls.DataBind(); Note that the "RowFilter" property of the DefaultView only seem to accept what would come after the "where" clause in an sql statement. right? What is i want add a select top(50) * ...., How do i proceed ? Many thanks in advance JB Tag: RecordStateChanged Object reference not set to an instance Tag: 109813
  - 5
    - New System.Transactions Namespace Hi, If I develop a component A and create a method DoSomething(string connectionString) and I have another component B with a method DoOtherThing(string connectionString) and from inside DoSomething() the B.DoOtherThing() will be called like public class A { public void DoSomething(string connectionString) { using (new TransactionScope()) { using (SqlConnection cn = new SqlConnection(connectionString)) { //do some db change here } //call B B o = new B(); o.DoOtherThing(connectionString); } } If there is an exception in B.DoOtherThing, the change in A will not be saved, right? according to the document, this should work, my question is in COM+ world, I will have to make component A "transaction.required" and make component B "transaction.supported" so the transaction context will actually span two component - but in .NET 2.0, the component B totally unaware of the context except being called inside the TransactionScope - how does this work and how could I specifically to abort the transaction in certain condition? Do I have to pass some transaction object to B? Thanks very much! John Tag: RecordStateChanged Object reference not set to an instance Tag: 109809
  - 6
    - "DataTable internal index is corrupted" - what's that? Hi there. I have a multithread application which handles pretty huge (~130000 records) dataset. Each thread gets record to handle, make some modification to its fields and gets next record. After all links have been modified main thread updates DB - simple actions. Now I have a problem - after some records have been processed (may be 1000, may be 100000) app throws an exception as in subject. Here is a code, which leads to crash: string strOldStatus = String.Empty; if (oRequestState.Row["InvalidCode"] == DBNull.Value || Convert.ToInt32(oRequestState.Row["InvalidCode"]) != (int)status) { oRequestState.Row["InvalidCode"] = (int)status; if (!IsStatusOK(status)) oRequestState.Row["URL_Title"] = String.Empty; } oRequestState.Row["Last_Verified"] = DateTime.Now; strOldStatus = (oRequestState.Row["InvalidCode", DataRowVersion.Original] == DBNull.Value) ? String.Empty : _ds.Statuses[(byte)oRequestState.Row["InvalidCode", DataRowVersion.Original]].ToString(); where oRequestState.Row is a DataRow, _ds.Statuses is a Hashtable. There is a relation in dataset of oRequestState.Row, but that relation is not on fields used in code snippet above. Relation is constructed before processing all the records. Here is a stacktrace: 05/02 14:04:33 [2220] HTTPRequester - Error in ProcessRequests: DataTable internal index is corrupted: '5'. Stack: at System.Data.RBTree`1.RBInsert(Int32 root_id, Int32 x_id, Int32 position) at System.Data.RBTree`1.RBInsert(Int32 root_id, Int32 x_id, Int32 position) at System.Data.Index.RecordStateChanged(Int32 oldRecord, DataViewRowState oldOldState, DataViewRowState oldNewState, Int32 newRecord, DataViewRowState newOldState, DataViewRowState newNewState) at System.Data.DataTable.RecordStateChanged(Int32 record1, DataViewRowState oldState1, DataViewRowState newState1, Int32 record2, DataViewRowState oldState2, DataViewRowState newState2) at System.Data.DataTable.SetNewRecordWorker(DataRow row, Int32 proposedRecord, DataRowAction action, Boolean isInMerge, Int32 position, Boolean fireEvent) at System.Data.DataRow.EndEdit() at System.Data.DataRow.set_Item(DataColumn column, Object value) at System.Data.DataRow.set_Item(String columnName, Object value) at HTTPTest.HTTPRequester.ProcessRequests() So I can't guess what leads to such exception after some minutes or hours of application work??? Additionaly after such exception had been thrown other app threads begin to throw "Index was outside the bounds of the array" exception on the same piece of code. Then stacktrace is as follows: 05/02 14:05:54 [1032] HTTPRequester - Error in ProcessRequests: Index was outside the bounds of the array. Stack: at System.Data.RecordManager.NewRecordBase() at System.Data.DataTable.NewRecord(Int32 sourceRecord) at System.Data.DataRow.BeginEditInternal() at System.Data.DataRow.set_Item(DataColumn column, Object value) at System.Data.DataRow.set_Item(String columnName, Object value) at HTTPTest.HTTPRequester.ProcessRequests() Can anybody shed a light on this issue? Would very appreciate that. Tag: RecordStateChanged Object reference not set to an instance Tag: 109806
  - 7
    - Future of SQLDMO What is the future of SQL DMO? Samples are available to interop DMO in C#. There is no equivalent of SQL DMO in .NET world. Will it be part of ADO.NET technology? What is the roadmap for DMO releases? Another thing is SQL DMO is MS SQL server specific. How about other databases like Oracle and DB2? Tag: RecordStateChanged Object reference not set to an instance Tag: 109805
  - 8
    - Generating the correct XML from a self-referential table I have a need to generate an XML based on a table in the DB. The table contains self-referential data, e.g. it has these columns employee_id employee_name employee_level manager_id manager_id is a foreign key to the employee_id. There can be many levels of this relationships. How can I generate an XML document with the correct hierarchy reflected? Since the levels are not known beforehand, I can't use FOR XML clause in the SELECT statement. And a DataRelation with parent and child from the same DataTable is not allowed in a DataSet. Thanks a lot Bob Tag: RecordStateChanged Object reference not set to an instance Tag: 109801
  - 9
    - possible to rank output with access database? i have an assignment for school that requires me to create a web search page and rank the results. however, we are to use an access database and not SQL. we have to come up with a custom ranking system. are there any examples of this anywhere? i'm not even sure how to start. Tag: RecordStateChanged Object reference not set to an instance Tag: 109794
  - 10
    - connection pooling hi, if I have an asp.net application where the requirement is that it should handle a peak of 5000 simultaneous user connections, how should I configure the connection pool? Should I create the connection pool to have a size of 5000 out of the gate? Is there a way to tune the connection pool programmatically at run time? What is the resource impact if I set the pool size to 5000? thanks in advance. Tag: RecordStateChanged Object reference not set to an instance Tag: 109793
  - 11
    - Debugging Stored procs in vs.net ide I am debugging a stored proc inside the IDE which is great. However, the stored proc dumps some data into temp tables. Is there a way to see the contents of the temp tables while in debug mode? Thanks P.S. I posted it earlier in c# ng but no help, thus repost here. Tag: RecordStateChanged Object reference not set to an instance Tag: 109791
  - 12
    - DatGrid Problem Hello: I am trying to display an Excel file in a DataGrid. I have Included my code. It runs through with no exception, but nothing appears in the datagrid Code: Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim XLConn As New OleDbConnection XLConn.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Test_001.xls;Extended Properties=""Excel 8.0;HDR=Yes;IMEX=1""" Dim XLCmd As New OleDbCommand XLCmd.Connection = XLConn Try XLConn.Open() Dim XLDA As New OleDbDataAdapter Dim XLDS As New DataSet("MainDS") Dim XLTableMain As DataTable = XLDS.Tables.Add("TableMainO") XLCmd.CommandText = "SELECT * FROM [Sheet1$]" XLDA.SelectCommand = XLCmd XLDA.Fill(XLDS, "TableMainO") Dim XLDV As New DataView Dim XLDataGrid As New DataGrid XLDV = New DataView(XLDS.Tables("TableMainO")) XLDataGrid.DataSource = XLDS XLDataGrid.DataMember = XLDS.Tables("TableMainO").ToString XLDataGrid.SetDataBinding(XLDS, "TableMainO") Finally XLConn.Close() End Try End Sub Thank You Prasun Tag: RecordStateChanged Object reference not set to an instance Tag: 109790
  - 13
    - How to make the element names the same in the XML generated from a DataSet I have a DataSet with 5 tables in it with data relations. All columns' ColumnMapping property is set to Attribute so in the output XML they are attributes. I would like all element names to be the same, e.g. "record". HOwever, by default the element names are the DataTable names and DataSet requires unique table names, how can I achieve this without having to loop through the resulting XML nodelist and change one by one? Tag: RecordStateChanged Object reference not set to an instance Tag: 109785
  - 14
    - VS2005 Beta 2 and Data Access Application Blocks (Enterprise Library) Well I am trying to compile an app With VS2005 Beta 2 that used the Data Access Application Blocks. I am getting this error There is an error in XML document (7, 48). In my XML it referes to this Application Blocks line <keyAlgorithmStorageProvider xsi:nil="true" /> Is there a fix or workaround for this? Thanks, Ed, Tag: RecordStateChanged Object reference not set to an instance Tag: 109775
  - 15
    - Question on SqlDataReader.Close Hi all, According the MSDN documentation on the SqlDataReader.Close method, it says that: The Close method fills in the values for output parameters, return values and RecordsAffected, increasing the amount of time it takes to close a SqlDataReader.... Is that mean before I can retrieve the value of stored procedure output parameters, I should call the SqlDataReader.Close method? But in some sample code I found on the web, it reads the output parameters before calling the Close method? Which is more appropriate? Thanks for help! Best Regards, Tony Tag: RecordStateChanged Object reference not set to an instance Tag: 109774
  - 16
    - Lightweight Dataset I am planning to design a lightweight dataset, any links or any pointers will be helpful. Tag: RecordStateChanged Object reference not set to an instance Tag: 109772
  - 17
    - Version of Excel in Connection String Hello: I am using the following connection string in my program Code: XLFileConn.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & filename & _ ";Extended Properties=""Excel 8.0;HDR=YES;IMEX=1""" Is there any other versions of Excel i can put in this connection string instead of Excel 8.0. Can I put excel 9.0 or 10.0. Is it possible to put an earlier version like 5.0 (is there an excel 5.0?). I guess i want to know what are my options are for that value. Thank You Prasun Tag: RecordStateChanged Object reference not set to an instance Tag: 109770
  - 18
    - bindingnavigator save button I installed the VS.NET 2005 Beta 2. I used a bindingnavigator on a form. Set its datasource property do a bindingsource. But, navigator does not show a Save button. Add new and delete buttons are there but there is no save button.. what is the problem.? thanks... Tag: RecordStateChanged Object reference not set to an instance Tag: 109769
  - 19
    - Detect change in DataBase Hello everybody, In my apps I use MSDE and I want detect all chanege in one table (most inportant is INSERT). This table is very long (over 50000 records). I want very fast refresh data in my DataSet. Thx Pawel Tag: RecordStateChanged Object reference not set to an instance Tag: 109761
  - 20
    - Req: Need suggestions for search algorithm Hi I'm working on a site which requires the users to specify a hotel at which they're staying in London. The complete list of hotels comes to something like 1600 records. Each record consists of Hotel Name, Street Address and Postcode. We need to make it as simple as possible for users to pick their hotel, but I don't want to put 1600 hotel names in a drop-down list, and we have to consider the fact that not every user is going to know the full name and address of their hotel. Furthermore, we have to assume that misspellings will be common and also the shortening of address elements. For example, "Road" could be entered as "Rd", "Rd." or "Road" "Street" could be "St", "St." or "Street" "Lane" could be "Ln", "Lne" or "Lane" etc Taking all these scenarios and requirements into hand can anyone suggest a fool-proof yet easy to use mechanism for providing this sort of search capability on a web-page? I'm using ADO.NET to interface to Sql Server 2000 db. Would Full-text indexing on this table be of any use? I'm intersted to know how people would go about this themselves. Thanks Ben Tag: RecordStateChanged Object reference not set to an instance Tag: 109758
  - 21
    - Power raising in a datacolumn expression Hello, Does anybody know how to use power raising in a datacolumn expression ?? Example: NewColumn = FirstColumn ^ 1.2345 or NewColumn = Power (FirstColumn,1.2345) -- Thanks in advance Jos Beelen Tag: RecordStateChanged Object reference not set to an instance Tag: 109757
  - 22
    - DataGrid with Master-Detail DataSet I have a DataSet with two tables which are in a master-detail relationship. How do I show a detail table in datagrid and some columns from a master table. (Ex.: Orders and a customer name for every order comes from a Customers table). Tag: RecordStateChanged Object reference not set to an instance Tag: 109749
  - 23
    - Problems with XML, XSD, Web, Services & InfoPath Hi all, Have been playing about with web services but unable to achieve what I am wanting and in attempts finding strange problems. I have created a web service for retrieving customer data and for updating the data using datasets. I have created a XML schema. I decided to use InfoPath for testing things out. Works great for getting the data. The data table on SQL Server 2000 allows nulls. If I was to change this I would have to split my customers into 2 tables. The table allows customer details to be stored as an individual or organisation. As a result some fields don't require any values so I have allowed nulls. When I come to update the data on InfoPath I can't edit the fields that contain nulls and the update fails because InfoPath only sends fields in the XML that do not contain null values. My thought of the way round this was to set minOccurs and maxOccurs to 1, I have also marked the elements with default values and set nill to true. When I test the web service method on the server minOccurs is set at 0 but the XML schema shows as 1. The Schema file is publicly available and this shows correct. Any ideas folks? Tag: RecordStateChanged Object reference not set to an instance Tag: 109747
  - 24
    - Date Format Problem - SQL Server Insert From Web Application Hi, I've written a short aspx file so that end users can insert lines into our SQL server database. The following string is sent by Internet Explorer to the database where it updates the relevant table - INSERT INTO Tbl_Manual([Data Date],[Staff ID], Flag1, Flag2, Flag3, Ref1, Ref2, Timestamp, Inputter) values('15/05/2005', '89', '1', '0', '0', '77', '8', '01/05/2005 08:54:10', 'HOME\username') The 2nd date is sent as a string into an nvarchar field so it causes no problems but the first (which is heading for a datetime field) is assumed by SQL to be MM/dd/yyyy format no matter what I try to do. All regional settings are set to UK English & the table in SQL correctly uses dd/MM/yyyy format so the above insert command fails thinking that I'm trying to add a date of the 5th of month 15. If I try input a date as mm/dd/yyyy format into the aspx page, an error is thrown back. Any ideas as to what's going wrong ? Thanks Steve Tag: RecordStateChanged Object reference not set to an instance Tag: 109738
  - 25
    - Advice on "converting" one DataTable to a different structure? Hi everyone-- I have a one-row DataTable that I need to manipulate. It consists of a series of three columns of related information. All the columns are strings. For example-- Col1 Col1Descrip Col1Value Col2 Col2Description Col3Value <etc> "AUTHOR" "email author" "John" "CC" "the copyee" "Rebecca" What I'd like to do is "pivot" the table, so to speak, so that it only has three columns; one for the field name, the field description, and the value. The single row I have now would be broken into separate rows of three columns each. Again, here's an example of what I'd like see in the end: NewCol NewColDescrip NewColValue "AUTHOR" "email author" "John" "CC" "the copyee" "Rebecca" Is there an optimal way of doing this? I suppose I could create a new DataTable with three columns, then walk through the original DataRow and build a new row every three columns along....it just sounds a little kludgey. I don't know, but I thought I'd ask if there were another, better way to do it. Thanks for the advice. Tag: RecordStateChanged Object reference not set to an instance Tag: 109728
- Next
  - 1
    - Double lock on iseries db2 ado.net transaction I'm seeing some odd locking behavior when using an DB2400 database and running an ado.net transaction. My code -- in simplified form, appears at the bottom. I want to run several INSERT statements using the same iDB2Connection and iDB2Command. Then I want to Commit() so that either all the data goes in, or not. What happens though is this: 1. After the first INSERT, a lock appears on the FILE 2. After the second INSERT, another lock appears on the FILE. 3. I can then add several more records, and no more locks appears 4. After the Commit(), one lock disappears but not the other. I have run the code with every available IsolationLevel, including the default, and the result is the same. My questions are: 1. Where could this second lock come from? 2. Why does Commit() not remove it? 3. What additional properties or commands do I need to account for to remove this lock? 4. I have read that there may be a journaling property that sets up an 'autocommit/rollback' in the event of a system crash -- could this be what's causing it? using System; using IBM.Data.DB2.iSeries; using System.Data; using System.Diagnostics; namespace simpleTtest { /// <summary> /// Summary description for Class1. /// </summary> class Class1 { /// <summary> /// The main entry point for the application. /// </summary> [STAThread] static void Main(string[] args) { // // TODO: Add code to start application here string connStr= "Data Source=192.168.NNN.NNN;User Id=XXXXXX;Password=XXXXX;Default Collection=DataLibrary;"; iDB2Connection p_iconn = new iDB2Connection(connStr); iDB2Transaction itrans=null; iDB2Command icmd=new iDB2Command("INSERT INTO " + "$MANINV.PEM610WD"+ "(" + "W1BATCH)" + "VALUES('100')", p_iconn); p_iconn.Open(); itrans = p_iconn.BeginTransaction( IsolationLevel.RepeatableRead ); icmd.Transaction=itrans; try { icmd.ExecuteNonQuery(); //after this statement a lock is generated icmd.ExecuteNonQuery(); //after this statement a second lock appears icmd.ExecuteNonQuery(); //no more locks; there are still two(2) at this point itrans.Commit(); // after commit, one lock is removed -- one remains! why...? } catch(Exception e) { Debug.WriteLine(e.ToString()); itrans.Rollback(); } finally { p_iconn.Close(); } } } } -- Texeme Construct http://texeme.com Tag: RecordStateChanged Object reference not set to an instance Tag: 109727
  - 2
    - Re: Using ms access how do I set column that can be of zero length TIA Sorry , I should have made it clear, how do I do it in code. Thanks. Tag: RecordStateChanged Object reference not set to an instance Tag: 109725
  - 3
    - Importing existing data Hi vs2005 beta2. I have created a sql server data file from within vs. Is there any way to import existing access tables & data into the sql server datafile? I have tried installed sql server 2004 developer from msdn but did not see any enterprise manager type tools that come with sql server 2000. What am I missing? Thanks Regards Tag: RecordStateChanged Object reference not set to an instance Tag: 109723
  - 4
    - IDataReader Read() method question Hello All! I am going to crazy and feeling myself so stupid but I don't understand such behavior. I have code: public int getNextAgentId() { Int32 agent_id = 0; IDataReader dr = dbap.DBDataReader("SELECT MAX(agent_id) FROM Agents"); if(dr.Read()) { agent_id = dr.GetInt32(0); } dr.Close(); return agent_id + 1; } where dbap is an instance of DB abstraction class, hence using IDataReader interface instead of concrete DB DataReader such as SqlDataReader. SELECT returns null due to database table is empty and I have error message "Data is Null. This method or property cannot be called on Null values." on line agent_id = dr.GetInt32(0); As I understand in the beginning datareader positioned before first record and when I call Read method it should point to first record but why it returns true in conditions when now rows returned from DB? Any ideas? Thanks in advance to all. Below my code of abstraction class (dbap is instance of DBAbstractionProcessor class): public class DBAbstractionProcessor { // implemented DB provider types public enum DbType { SQLServer, OLEDb, ODBC }; private DbType dbtype; private AbstractDBFactory dbf; public DBAbstractionProcessor(DbType db_type) { this.dbtype = db_type; } private void selectDbType() { switch(this.dbtype) { case DbType.SQLServer: this.dbf = new SQLServerDb(); break; case DbType.ODBC: this.dbf = new OdbcDb(); break; case DbType.OLEDb: this.dbf = new OleDb(); break; } } public void init(string dburl) { this.selectDbType(); this.dbf.init(dburl); } public void init(string dburl, string user, string passwd) { this.selectDbType(); this.dbf.init(dburl,user, passwd); } public void connect() { dbf.connect(); } public void disconnect() { dbf.disconnect(); } public DataSet DBAPSelectQuery(string cmd) { return this.dbf.DBSelectQuery(cmd); } public void DBAPInsertQuery(string cmd) { this.dbf.DBInsertQuery(cmd); } public IDataReader DBDataReader(string query) { return this.dbf.DBDataReader(query); } } Factory class which implements factory design pattern: /// <summary> /// Factory Design Patterns implementation. /// At the present time abstraction if MS SQL Server, ODBC and OLEDB /// interfaces implemented. In case of neccessety, any other interfaces /// can be easily implemented. /// </summary> public abstract class AbstractDBFactory { // database url string protected string url = null; // database username protected string username = null; // database password protected string password = null; // simple initialize by url public void init(string dburl) { if(dburl == null) { throw(new ArgumentException("Illigal agruments")); } this.url = dburl; } // full initialize public void init(string dburl, string user, string pass) { this.init(dburl); this.username = user; this.password = pass; } // clear all settings public void destroy() { this.url = null; this.username = null; this.password = null; } // abstract methods which implemented by SQLServerDb, OdbcDb and OleDb classes abstract public void connect(); abstract public void disconnect(); abstract public DataSet DBSelectQuery(string cmd); abstract public void DBInsertQuery(string cmd); abstract public IDataReader DBDataReader(string cmd); } And SQL Server implementation: /// <summary> /// MS SQL Server interface implementation. /// </summary> public class SQLServerDb : AbstractDBFactory { // connector private SqlConnection sqlCon; public override void connect() { // if base class which stores url, username and passwords not initilized // throw exception if(base.url == null) { throw(new ApplicationException("Class is not initialized. Please run init() first.")); } else { //Disable pooling for sql server if(base.url.IndexOf("Pooling") == -1) { base.url += ";Pooling=false"; } // if username and password properties exists initilize by them otherwise by url if(base.username != null && base.password != null) { this.sqlCon = new SqlConnection(base.url + ";uid=" + base.username + ";pwd=" + base.password); LoggingProcessor.Info("url uid pwd init"); } else { this.sqlCon = new SqlConnection(base.url); LoggingProcessor.Info("url - " + base.url); } try { sqlCon.Open(); } catch (Exception e) { throw new Exception("SQL Server error: " + e.ToString()); } LoggingProcessor.Info("sql server connection established"); } } // simple select query // returns DataSet public override DataSet DBSelectQuery(string cmd) { DataSet ds = new DataSet(); try { if(this.sqlCon.State == ConnectionState.Closed) { this.connect(); } SqlDataAdapter sqlDA = new SqlDataAdapter(); sqlDA.SelectCommand = new SqlCommand(cmd, sqlCon); sqlDA.Fill(ds); } catch (Exception e) { throw new Exception("SQL Server error: " + e.ToString()); } finally { sqlCon.Close(); } return ds; } // simple insert query public override void DBInsertQuery(string cmd) { try { if(this.sqlCon.State == ConnectionState.Closed) { this.connect(); } SqlCommand sqlCmd = new SqlCommand(cmd, this.sqlCon); sqlCmd.Prepare(); sqlCmd.ExecuteNonQuery(); } catch (Exception e) { throw new Exception("SQL Server error: " + e.ToString()); } } // DBDataReader - provides selection and returns SqlDataReader public override IDataReader DBDataReader(string cmd) { try { if(this.sqlCon.State == ConnectionState.Closed) { this.connect(); LoggingProcessor.Info("connection is not initialized. initializing..."); } SqlCommand sqlCmd = new SqlCommand(cmd, this.sqlCon); LoggingProcessor.Info(cmd); //sqlCmd.Prepare(); return sqlCmd.ExecuteReader(); } catch (Exception e) { throw new Exception("SQL Server error: " + e.ToString()); } } // disconnect public override void disconnect() { if(sqlCon.State != ConnectionState.Closed) { try { this.sqlCon.Close(); } catch (Exception e) { throw new Exception("SQL Server error: " + e.ToString()); } } } } Best regards, /Gelios Tag: RecordStateChanged Object reference not set to an instance Tag: 109719
  - 5
    - Opening from Excel into a dataset, issue with mixed datatypes I have an excel sheet with a column of mixed data types, i.e., numeric & text. ADO.NET is scanning the first few rows and deciding on numeric so when we come across text, the data becomes blank. That being the case I set the extended properties setting to include IMEX=1 but this seems to be of no help. Below is the stripped out code of what I am attempting to do. Thank you for your help. string sConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + Server.MapPath("~/Output/myData.xls") + ";" + "Extended Properties=\"Excel 8.0;IMEX=1;HDR=NO;\""; OleDbConnection oleCon = new OleDbConnection(); oleCon.ConnectionString = sConnectionString; oleCon.Open(); OleDbCommand objCmdSelect =new OleDbCommand("SELECT * FROM [2005$A5:A133]", oleCon); OleDbDataAdapter objAdapter1 = new OleDbDataAdapter(); objAdapter1.SelectCommand = objCmdSelect; DataSet objDataset1 = new DataSet(); objAdapter1.Fill(objDataset1); DataGrid1.DataSource = objDataset1.Tables[0]; DataGrid1.DataBind(); oleCon.Close(); oleCon.Dispose(); Tag: RecordStateChanged Object reference not set to an instance Tag: 109710
  - 6
    - How the frick do you call a stored procedure when using OdbcDataAdapter?!? And why the frick is it sooo damn hard to find information on this crap, anyway?!? Help! -Skipward Tag: RecordStateChanged Object reference not set to an instance Tag: 109699
  - 7
    - Scrolling and retrieving rows similar like ado recordset Hi, I working on implementing a scrolling and record navigation with ADO.NET. In ado recordset having builtin caching/paging and record navigation methods. but i could find a similar conecpts in ADO.NET classes.. Am i missing something?? In dataset class i cannot set pagesize/cachesize, so if i execute a query with a large resultsets with dataset all the rows loaded in the memory. so iam not getting any cursor navigation conecpt benefits in ado.net classes??? Hari Tag: RecordStateChanged Object reference not set to an instance Tag: 109693
  - 8
    - Needing Help Hi, i am trying to make a window application that create graphs (plot data as in excel) for a given set of points, how can i do this? thanx -- Message posted via http://www.dotnetmonster.com Tag: RecordStateChanged Object reference not set to an instance Tag: 109691
  - 9
    - Bidirectional cursor navigation Hi, Is there any class supports bidirectional cursor in the ADO.NEt framework? I was looking some of the samples and only talks about SqlDataReader (forward only cursor). Or is there any way i can make use of database cursors in my dotnet application to navigate the records from a table.? Hari Tag: RecordStateChanged Object reference not set to an instance Tag: 109687
  - 10
    - using a dataReader with StoredProc I have an oracle storedProc that takes one input parameter and 15 output parameters. Can I get the results of the output parameters in a datareader or must I add 15 output parameters? thanks john Tag: RecordStateChanged Object reference not set to an instance Tag: 109682
  - 11
    - How to provide a feedback in accessing the BLOB type data? How to let the user know the progress while accessing BLOB type data? The feedback such as the number of bytes readed/written to database. Regards, ZhangZQ Tag: RecordStateChanged Object reference not set to an instance Tag: 109679
  - 12
    - Comparing 2 datasets (or datatables) I want to compare two datasets (of 2 datatables). I just need to know whether the 2 datasets are same or different. I do not want to know how it differs. (I would be nice to have though).. Is there any easy way to accompilsh this. Thanks Tag: RecordStateChanged Object reference not set to an instance Tag: 109673
  - 13
    - stored proc /w Oracle and Ado.Net Can someone help me with a very simple task I am trying to execute a stored procedure in an Oracle database using Ado.Net. The following is a code snippet conn = New OracleConnection(mOracleConnectionString) cmd = New OracleCommand cmd.Connection = conn conn.Open() cmd.CommandType = CommandType.StoredProcedure cmd.CommandText = "TW_USER_TEST3" cmd.ExecuteReader(CommandBehavior.Default) The stored proc does not have any input or output parameters. I created it for testing purposes. I had a stored proc that did have input and output but I was getting errors so I thought to create the simplest store proc. The proc doesn't even do anything. I am getting the following error: >> An unhandled exception of type 'System.Data.OracleClient.OracleException' occurred in system.data.oracleclient.dll Additional information: ORA-06550: line 1, column 7: PLS-00201: identifier 'BRAVO_CL21.TW_USER_TEST3' must be declared ORA-06550: line 1, column 7: PL/SQL: Statement ignored >> The following is the stored proc: >> CREATE OR REPLACE procedure tw_users_test3 as begin null; end; / >> I would appreciate any help thank you John Tag: RecordStateChanged Object reference not set to an instance Tag: 109669
  - 14
    - ODBCConnection and ASP.NET I have an ODBC connection (to Perforce) using a System DSN. In a console app I can open the connection, in an ASP.Net webform I can't, and get the error... [OdbcException: ERROR [HY000] [ ERROR [HY000] [] I assume it must be permissions? I have tried a few things, firstly making ASPNET (I'm running IIS5) andAdmin user, then giving it permissions to the System DSN registry key, but to no avail. I'm using the 1.1 Framework and the System.Data.Odbc.OdbcConnection object. Anbody got any ideas? Tag: RecordStateChanged Object reference not set to an instance Tag: 109668
  - 15
    - Continious DataTable.Select without AcceptChanges on every table leaks memory Hi everybody, we had very strange memory usage in our application when continiously updating a dataset. We were able to exactly localize the problem in the datatable.Select method. Each time we check the datatables for changes with Select, there is an internal index build. These indexes are later deleted when you pass the datatable to the dataadapter. But in our code we have a lot of tables in the dataset where we check all for changes and only update the ones with changes. When the changes only occur in the same tables for a long time, the other tables get more and more indexes consuming a lot of memory. The following piece of code demonstrate this behaviour. It generates more than 400Meg on my machine, and it's the Select method doing this! Only a call of the AcceptChanges method clears the memory. If your machine doesn't have that much memory, be careful! We have not examined the problem on .NET SP1, perhaps it is fixed. For me, creating a static index without reusing it anytime looks like a bug. Are there any designguides saying that this is not the right way to use/update datasets? Doesn't anybody work with datasets like that? Any comments on that? Helge ---------------------------------------------------- class Class1 { [STAThread] static void Main(string[] args) { // build a very simple DataSet System.Data.DataSet ds = new DataSet(); System.Data.DataTable table = ds.Tables.Add("Table"); table.Columns.Add(new System.Data.DataColumn("ID", typeof(Guid))); // add some Data to your one table to make the effect more dramatic ;-) for (int i = 0; i< 10000; ++i) { System.Data.DataRow row = table.NewRow(); row["ID"] = Guid.NewGuid(); table.Rows.Add(row); } table.AcceptChanges(); // dump memory before Class1.DumpMemory(); for(int i = 0; i <10000; ++i) { // this simple select (doing nothing) executed 10000 times generates over 400Meg of memory! // And you don't get rid of it with GC.Collect()! table.Select(null,null,DataViewRowState.ModifiedCurrent); } // dump memory after! Suprise! Class1.DumpMemory(); // only if you call AcceptChanges the memory is cleared! ds.AcceptChanges(); Class1.DumpMemory(); } static void DumpMemory() { System.GC.Collect(); System.Console.WriteLine("TotalMemory: " + GC.GetTotalMemory(true).ToString()); } } Tag: RecordStateChanged Object reference not set to an instance Tag: 109667
  - 16
    - OnRowUpdated, Rollback in DB, ConcurrencyException and RowState question. Please give your opinions. Hello. If you think this post is too long to read please scroll to the bottom and read the last two sentences. Thank you :) I have a problem which I cannot find a good solution to and hopefully I can get some ideas from the readers of this group. I will first describe my environment for you; I have a database without constraints. It has a lot of tables ofcourse and among all of them are two specific tables. Lets call them Customer and CustomerDetails. In the Customer table there are some columns ofcourse and the last column is DetailsId that works as reference to the CustomerDetails table. The column datatype is an int and points out the Id column in the CustomerDetails table. The Id column in CustomerDetails has autoincrement turned on and is the primary key column. In the dataset in the C# application there is a relation between Customer and CustomerDetails (DetailsId in Customer refers to Id in CustomerDetails). Before a Customer has been "opened" for the first time in the Application the CustomerDetails table does not have any entries which is refered to from the Customer row. The DetailsId value of the specific customer is DBNULL. Now, imagine the following scenario: Person A opens up a customer in the application. Automatically a row in CustomerDetails is added and it's Id value is automatically assigned. This value is then, due to the relation between the tables also inserted into the customer row's DetailsId column. Lets say the value is 20 (because there are 19 other entries in CustomerDetails already). Then Person B opens up the same customer in the application. Same thing happens with the CustomerDetails table in the dataset. It gets a new row with Id 20. Person A changes something in the customer row and then saves all changes back to the DB. Everything works fine so far. Person B changes the same value in the customer row and then also tries to save. What happens now is that first the CustomerDetails table in the dataset is saved to the db. When this happens the RowUpdated event triggers and we get a hint that the actual value of Id has changed in the DB so it is now 21 (since 20 was already taken). With the help of the relation between the tables also the DetailsId value in the Customer table is changed to 21. Then some other updates follow, but finally there is a concurrency in the Customer table since both person A and B have tried to changed the very same rowvalues. A rollback is performed in the database. Person B is informed that a concurrenyexception has been thrown and is now given two options. First option is to loose all of his changes due to the concurrency. Second option is to override the data in the database with his specific changes. The person B chooses the second option since he thinks his changes are more important. What happens now is that data is collected from the database into a new dataset. Then this dataset is merged into the first dataset (in which all of person B's changes are). It is merged with the "preserve changes" flag so that all of the changes that person B has made are still there. Since the DetailsId value has been changed in the RowUpdated event to 21 this value is still 21 in both Customer and CustomerDetails. Though, when the new dataset was filled from the database there was already a row in CustomerDetails (with Id value 20). So after the merge the CustomerDetails table now holds two rows. One with Id 20 and one new with Id 21. In the Customer table the row's value is 21 (which is correct). Now, person B saves for the second time to the DB. Now there is no concurrency and everything seemd to work fine. But everything is certainly not fine. The first problem is that no row in the Customer table refers to the row in CustomerDetails which has Id 20. The second problem is that the row in CustomerDetails with Id value 21 is never saved to the DB so the row in the Customer table now refers to a row that does not exist in the DB. The first problem you probably understand why it occured. The second problem is a little more tricky to understand. Atleast it was for me. The thing is that when person B saved to the DB the very first time all of the rows that were saved before the concurrency occured had it's rowstate property changed from added/modified to unchanged. Then the rollback was done in the DB, but the dataset were still "changed". That is why the row in CustomerDetails was not saved when person B saved to the DB the second time. To fix the second problem I have this solution in mind; If I first make a copy of the changes (before person B is saving for the first time) in the dataset with dataset.GetChanges() and use this "copy" when I update the DB. If everything goes fine with the DB update I can merge any changes (that could have been done due to RowUpdated event activity) from the "copy" dataset back to the original dataset. If something goes wrong with the DB update (i.e. if a concurrency exception is being thrown), I will still have the original dataset unchanged with all rowstates. I can then still give person B the option to "override" the concurrency, which means I refresh a new dataset from the DB and merge the changes into it. Then person B tries to save once again. Question now is, what will happen if I implement my solution? What if the DetailsId in person B's dataset is something different from what's already in the DB (say, 22). Will the existing row (21) that person A once saved have it's Id value changed to 22 du to the merge between the newly refreshed dataset and person B's dataset? Or will there just be a new row added (22) to CustomerDetails so that problem 1 occurs (row 21 will be left on it's own with reference from the Customer table) ? I know that this was a quite big post but I felt I needed to explain everything good enough to get good help. I am VERY thankful if you find a working solution for me. Regards, David. Tag: RecordStateChanged Object reference not set to an instance Tag: 109666
  - 17
    - Require Help Regarding Deployment...... This is a multi-part message in MIME format. ------=_NextPart_000_000A_01C54CB2.5B42EED0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Every Body, I build an application using vb.net. Now i m deploying on the client system. I know that the deployment automatically check the .net framework on the = client system at startup. I include the .net framework in the deployment setup. I want that if the framework is not installed on the client system then = my deployment wizared automatically install the framework which i = include in the deployment package. How can i do this. What are the setttings are needed regarding this. Regards, Muhammad Jamil Nawaz ------=_NextPart_000_000A_01C54CB2.5B42EED0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=3DContent-Type content=3D"text/html; = charset=3Diso-8859-1"> <META content=3D"MSHTML 6.00.2900.2604" name=3DGENERATOR> <STYLE></STYLE> </HEAD><FONT face=3DArial><FONT size=3D2> <BODY> <DIV>Hi Every Body,</DIV> <DIV> </DIV> <DIV>I build an application using vb.net.</DIV> <DIV>Now i m deploying on the client system.</DIV> <DIV>I know that the deployment automatically check the .net framework = on the=20 client system at startup.</DIV> <DIV>I include the .net framework in the deployment setup.</DIV> <DIV>I want that if the framework is not installed on the client system = then my=20 deployment wizared automatically install the framework which i include = in the=20 deployment package.</DIV> <DIV> </DIV> <DIV>How can i do this. What are the setttings are needed regarding = this.</DIV> <DIV> </DIV> <DIV>Regards,</DIV> <DIV> </DIV> <DIV>Muhammad Jamil Nawaz</DIV></BODY></HTML></FONT></FONT> ------=_NextPart_000_000A_01C54CB2.5B42EED0-- Tag: RecordStateChanged Object reference not set to an instance Tag: 109657
  - 18
    - Large jumps in number connections to SQL DB and Connection Pool Not really sure if I have a problem or not...but, I want to try and understand what is going on. With that said, I haven't ruled out that it's a code problem, but I want to post to see if anyone has seen similar behavior. Basically, throughout the day, we may see "large" jump in the number of connections to our SQL DB and a corresponding jump in the connection pool within a short period of time, i.e., 100+ connection increase in 2 to 3 seconds. The number of users during these jumps are steady...that is, we don't have a large increase of end users (it's an internal call center app). Like I said, I haven't ruled out there being some kind of problem in the application that generates the connections, but I just want to try and persue all avenues. Thanks in advance. Tag: RecordStateChanged Object reference not set to an instance Tag: 109653
  - 19
    - Table Mapping with Typed Dataset I've created a strongly typed DataSet, with a 2 related tables. a couple of the columns in the parent are computed with expressions. One of which is a Sum of a Child.column (Sum(Child.UnitCost). Eitherway, since adding these expressions, I'm getting a InvalidOperationException when I execute the Update method of corresponding DataAdapter on the parent. The column names haven't changed from the underlying data source, a table on sql server. Admittedly, at this point in the execution, the child table has not been filled yet, but that's fine, the expression columns can just stay null at this point. What am I doing wrong? Is it case that all expression columns are not meant to be mapped back, but instead are just for use within the dataset? :O( Tag: RecordStateChanged Object reference not set to an instance Tag: 109652
  - 20
    - Using gcroot template class and understanding memory utilization. Hi Guys, Iam using a managed dll in my unmanaged MFC application to use ADO.NET classes. so i have a class in the manged dll declared as follows : class __declspec ( dllexport ) CADOInterface { public: //////////// //---- ////////////// int GetCacheRecordIndex(int recordId); public: ///--- /// other declarations /// gcroot<DataTable*> m_pDataTable; }; In one of the method implementation, i have used a local DataRowCollection class. Since the CADOInterface is created in the unmanaged appllication, do i need to use the gcroot template class with the local DataRowCollection class??? if don't use with gcroot class, is there any memory leak??? int CADOInterface ::GetCacheRecordIndex(int recordId) { /// assume m_pDataTable table has some rows gcroot<DataRowCollection*> rows = m_pDataTable->Rows; if(rows) { gcroot<DataRow*> row; int recId; for(int i=0; i < rows->Count; i++) { row = rows->Item[i]; recId = *dynamic_cast<__box Int32*>(row->get_Item(S"RecordId")); if(recId == recordId) return i; } } return 0; } Also do i need to always use gcroot template class with managed classes, when iam using in a unmanaged class?? Hari Tag: RecordStateChanged Object reference not set to an instance Tag: 109650
  - 21
    - Using ms access how do I set column that can be of zero length TIA Tag: RecordStateChanged Object reference not set to an instance Tag: 109644
  - 22
    - Finding out ADO.NET version How do i find out what version of ADO.NET is being used in my .NET application. Iam building vc++ application in visual studio.net 2003 (7.1 version) and .NET framework version 1.1. I would like use the new feature of ADO.NET 2.0 and need to know i have the correct ado dll's on my system.? The dlls i have on C:\Program Files\Common Files\System\ado folder is msado15.dll like that, is it 1.x or 2.0 version? Hari Tag: RecordStateChanged Object reference not set to an instance Tag: 109643
  - 23
    - Repost:Adding rows to DataTable and DataView issue Hi, I thought I had my problem with the dataview and InsertAt fixed, but nope. It looks like it works at first, but then the dataview starts going nuts. And I experience the issue from my other recent post about the dataview containing datarowviews that don't point to an actual row. In fact, if I check the source table, my table can have say 4 rows. But the DataView will have 5, one of which is this phantom one that doesn't point to a real DataRow. I am experiencing something described here: http://groups-beta.google.com/group/microsoft.public.dotnet.framework.windowsforms/browse_thread/thread/5b274676ce51dc99/dfb4d5d987d4b371?q=DataViewRowState.CurrentRows+insertat&rnum=1&hl=en#dfb4d5d987d4b371 Seems there is no real solution other then to make a fake column that keeps track of row order. Except then, every time you insert one not at the end, you have to renumber all the rows after it. Help, someone, anyone? Tag: RecordStateChanged Object reference not set to an instance Tag: 109642
  - 24
    - Filtering on a Hierarchical recordset Hello, I have a dataset with multiple tables linked through parent child relationships. I want the user to be able to filter on a child table and I'm using the DataViewManager to set the rowfilter for all the tables in the dataset. This does not seem to work. Only the filter on the parent table works. This is an examle of what I'm currently doing: //Create DataView settings for each Table using the DataViewManager m_oppDVM = new DataViewManager(myDataset); // Loop through the DataViewSettings and set Rowfilter for each Table individually String oppTable; foreach (DataViewSetting DVS in m_oppDVM.DataViewSettings) { // Set Default Sort Order = Primary Key for all Tables DVS.ApplyDefaultSort = true; // Set individual Sort and Rowfilter ... oppTable = DVS.Table.ToString(); switch (oppTable) { case "Table1": { DVS.RowFilter = "filter"; } case "Table2": { DVS.RowFilter = "filter"; } case "Table2": { DVS.RowFilter = "filter"; } } } To give you an example, if the user sets a filter on table2, I want to be able to show the user all rows (both parent and child) which match the filter. I am using the wrong approach?? Thanks Tag: RecordStateChanged Object reference not set to an instance Tag: 109639
  - 25
    - DataView mystery Hi, For some reasons, these lines of code sometimes differ in results: myDataView.Item(1).row("MyColumn") myDataView.Item(1)("MyColumn") Sometimes the second version throws a NullReferenceException in the System.Data.DataView.IsOriginalVersion(Int32 index) method. So the DataRowView object being indexed to exists. And it definitely exists, because the first version of the code works fine. Can anyone tell me why going through the underlying row is OK, but not through the indexer in datarowview directly? Tag: RecordStateChanged Object reference not set to an instance Tag: 109638

Object reference not set to an instance of an object.
at System.Data.DataTable.RecordStateChanged(Int32 record1, DataViewRowState
oldState1, DataViewRowState newState1, Int32 record2, DataViewRowState
oldState2, DataViewRowState newState2)
at System.Data.DataTable.SetNewRecord(DataRow row, Int32 proposedRecord,
DataRowAction action, Boolean isInMerge)
at System.Data.DataRow.SetNewRecord(Int32 record)
at System.Data.DataRow.EndEdit()
at System.Data.DataRow.set_Item(DataColumn column, Object value)
at System.Data.DataRowView.SetColumnValue(DataColumn column, Object
value)
at System.Data.DataRowView.set_Item(String property, Object value)
at Lumedx.CardioDoc.UDF.CheckBoxAdapter.checkBox_CheckStateChanged(Object
sender, EventArgs e)

I get the above exception when I try to change the value of a column of a
data row view in the CheckStaeChanged event. The column is the same one the
checkbox's CheckState is bound to.

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Re: RecordStateChanged Object reference not set to an instance by Val

Val
Tue May 03 17:43:27 CDT 2005

Hi Sankar,

This error means that your reference to the datarow or datacolumn probably
is Nothing and you try to change a value for it. Try to debug a code and see
if it is not a Nothing

--
Val Mazur
Microsoft MVP

http://xport.mvps.org

"Sankar Nemani" <snemani@nospamlumedx.com> wrote in message
news:u0x00u$TFHA.2996@TK2MSFTNGP15.phx.gbl...
> Object reference not set to an instance of an object.
> at System.Data.DataTable.RecordStateChanged(Int32 record1,
> DataViewRowState oldState1, DataViewRowState newState1, Int32 record2,
> DataViewRowState oldState2, DataViewRowState newState2)
> at System.Data.DataTable.SetNewRecord(DataRow row, Int32 proposedRecord,
> DataRowAction action, Boolean isInMerge)
> at System.Data.DataRow.SetNewRecord(Int32 record)
> at System.Data.DataRow.EndEdit()
> at System.Data.DataRow.set_Item(DataColumn column, Object value)
> at System.Data.DataRowView.SetColumnValue(DataColumn column, Object
> value)
> at System.Data.DataRowView.set_Item(String property, Object value)
> at
> Lumedx.CardioDoc.UDF.CheckBoxAdapter.checkBox_CheckStateChanged(Object
> sender, EventArgs e)
>
> I get the above exception when I try to change the value of a column of a
> data row view in the CheckStaeChanged event. The column is the same one
> the checkbox's CheckState is bound to.
>
>

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