How to put NULL into database column

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  - 1
    - Error connecting to Oracle Using some .Net code to connect to Oracle the follow error message is now being displayed File or assembly name Oracle.DataAccess, or one of its dependencies, was not found. Exception Details: System.IO.FileNotFoundException: File or assembly name Oracle.DataAccess, or one of its dependencies, was not found. This section of code has not been changed and the a test ODBC connection can be successfully made from the web server. In the Windows path is the folder containing the dll as the first folder location. Does anybody know why this error is occurring and how to resolve it? Tag: How to put NULL into database column Tag: 143914
  - 2
    - Getting data as returned from SQL Server is there anyway to get the data as it is returend from the sql server? I have a command object that returns 100,000 records which I want to see as they come back... kinda like how SQL Managment studio does when you execute a query it shows the data as it comes in... any way to do that in ADO.NET? I am using .NET 3.5 on VS 2008 thanks! Tag: How to put NULL into database column Tag: 143907
  - 3
    - Timeout in .NET but not in Management Studio I have a SQL Server 2005 database which I use from ASP.NET 2.0. I invoke stored procedures using SqlConnection, SqlCommand and SqlDataReader from System.Data.SqlClient. When I invoke a SP from SQL ServerManagement Studio it executes in 3 seconds and returns 4000 rows. When the same procedure is invoked from SqlCommand.ExecuteReader it takes more than 30 seconds an sometimes renders a timeout in .NET. In Profiler the invocations of the SP:s look exactly the same. If I trace Scans they behave differently though. The time difference lies within the Scans but also the patterns of Scan:Started - Scan:Stopped differ. In my connectionStrings the providerName is System.Data.SqlClient. What can make SQL Server execute the query in two different ways? They seem to be getting different execution plans. How can I make .NET use the faster way? Regards Ove Tag: How to put NULL into database column Tag: 143897
  - 4
    - Incredibly slow writing by CSV driver Since my application uses the Excel driver to read some files, I used the same Excel driver to write some CSV files. I also tried using the Text driver to write CSV files. The results are correct but they take enormous amounts of CPU time. Of course I know how to write a CSV file using plain old Shift-JIS character strings and quotation marks and commas, and probably I'll do that in order to speed up this operation, but the question still remains. Why is this so slow? The sample data table had 213 rows (header plus 212 data rows) and 25 columns, all strings (some of them empty strings). The total file size on disk is 34KB. The computations and database operations in memory take a few milliseconds, not even noticeable when running under a debugger. But the call to dataAdapter.Update(dataTable); takes 55 SECONDS OF CPU TIME on a Pentium 4 running at 3 GHz. It occupies 100% of one CPU core for 55 seconds. Actual time to write the file might be a few hundred milliseconds since 34KB occupies several NTFS structures. Anyway, this thing isn't disk bound, and it's not CPU bound in my code, it's CPU bound in the Update method. What is going on here? #undef UseOdbc // Use OleDb string fileName = @"C:\test.csv"; // (not really) string Headers[] = new string[25] { "1", "2", "3", /* ... */ "25" }; int columnCount = 25; // (not really) FileInfo fileInfo = new System.IO.FileInfo(fileName); string dirName = fileInfo.DirectoryName; string tableName = fileInfo.Name; #if UseOdbc OdbcConnection connection = new OdbcConnection( "Provider=MSDASQL;" + "DRIVER={Microsoft Text Driver (*.txt; *.csv)};DBQ=" + dirName + ";Extended Properties='Text;Extensions=asc,csv,tab,txt;" + "HDR=Yes;FMT=Delimited'"); connection.Open(); OdbcDataAdapter dataAdapter = new OdbcDataAdapter( "SELECT * FROM [" + tableName + "]", connection); OdbcCommand insertCmd = new OdbcCommand(); OdbcType varcharType = OdbcType.VarChar; #else // OleDb OleDbConnection connection = new OleDbConnection( "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + dirName + ";Extended Properties='Text;Extensions=asc,csv,tab,txt;" + "HDR=Yes;FMT=Delimited'"); connection.Open(); OleDbDataAdapter dataAdapter = new OleDbDataAdapter( "SELECT * FROM [" + tableName + "]", connection); OleDbCommand insertCmd = new OleDbCommand(); OleDbType varcharType = OleDbType.VarChar; #endif // OleDb DataTable dataTable = new DataTable(tableName); DataColumnCollection dataColumns = dataTable.Columns; int columnNum; string dataColumnName; DataColumn dataColumn; StringBuilder insertCmdHead = new StringBuilder( "INSERT INTO [" + tableName + "] ("); StringBuilder insertCmdTail = new StringBuilder("VALUES ("); StringBuilder fileHeader = new StringBuilder(); for (columnNum = 0; columnNum < columnCount - 1; columnNum++) { dataColumnName = Headers[columnNum]; dataColumnName = dataColumnName.Replace('\n', ' '); dataColumn = dataColumns.Add(dataColumnName); dataColumn.DataType = typeof(string); dataColumn.DefaultValue = ""; insertCmdHead.Append("[" + dataColumnName + "], "); insertCmdTail.Append("?, "); insertCmd.Parameters.Add(dataColumnName, varcharType, 255, dataColumnName); fileHeader.Append("\"" + dataColumnName + "\","); } dataColumnName = Headers[columnCount - 1]; dataColumn = dataColumns.Add(dataColumnName); dataColumn.DataType = typeof(string); dataColumn.DefaultValue = ""; insertCmdHead.Append("[" + dataColumnName + "]) "); insertCmdTail.Append("?)"); insertCmd.Parameters.Add(dataColumnName, varcharType, 255, dataColumnName); insertCmd.CommandText = insertCmdHead.ToString() + insertCmdTail.ToString(); insertCmd.Connection = connection; dataAdapter.InsertCommand = insertCmd; fileHeader.Append("\"" + dataColumnName + "\""); for (int rowNum = 0; rowNum < 212; rowNum++) // (not really) { DataRow dataRow = dataTable.NewRow(); dataRow[2] = "hi i'm 2"; // (not really) dataRow[18] = "18"; // (not really) dataRow[19] = "19"; // (not really) // (around half the cells default to empty strings) dataTable.Rows.Add(dataRow); } StreamWriter fileWriter = new StreamWriter(fileInfo.Create(), Encoding.Default); fileWriter.WriteLine(fileHeader.ToString()); fileWriter.Close(); fileWriter.Dispose(); // UP TO THIS POINT TAKES A FEW MILLISECONDS, OK // // 55 SECONDS OF CPU TIME (Pentium 4 3 GHz) TO WRITE 34 KILOBYTES dataAdapter.Update(dataTable); // 55 SECONDS TO WRITE 34 KILOBYTES // 55 SECONDS OF CPU TIME (Pentium 4 3 GHz) TO WRITE 34 KILOBYTES // // OK AFTER THIS dataAdapter.Dispose(); dataTable.Dispose(); connection.Close(); Tag: How to put NULL into database column Tag: 143894
  - 5
    - RAD apps for db development Hi Are there any RAD apps to speed up one-many db application development that are worth considering? Thanks Regards Tag: How to put NULL into database column Tag: 143889
  - 6
    - Reformed access user needs advise for future Hi Many a times I have been told off here for asking question on a backend other than sql sever. So I have finally seen the light and have decided to take up my next project with sql server backend (vb.net front). So here is my question; What are the recommended db development guidelines to achieve both a) a good user experience of being able to scroll to any record using record navigation buttons and b) the db efficiency requirement of not loading too many records in dataset at one time. If there is such a strategy to which many agree then there should be a sample code app somewhere. It would help me enormously to see the guts of an actual well written db app - no matter how trivial as long as it covers the necessary detail - instead of advise like don't do this or that without the coding specifics. So here is a chance for the worthy to lead a recent convert (albeit reluctant due to self deficiency on sql server side). Thanks Regards Tag: How to put NULL into database column Tag: 143885
  - 7
    - Getting Casting error when passing paramarray with Microsoft.Pract I am using Microsoft.Practices.EnterpriseLibrary.Data as DataLayer in my project. I am facing problem to pass objSqlParam array to methods provided by Microsoft.Practices.EnterpriseLibrary.Data as DataLayer itseld(i.e. db.ExecuteNonQuery(storedProcedureName, parameterValues) and as on same with others) I am doing as below: Dim objSqlParam As SqlParameter() = Nothing objSqlParam = New SqlParameter(1) {} objSqlParam(0) = New SqlParameter("@CustId", SqlDbType.Int) objSqlParam(0).Direction = ParameterDirection.OutPut objSqlParam(0).Value = 1 objSqlParam(0) = New SqlParameter("@CustName", SqlDbType.Varchar) objSqlParam(0).Direction = ParameterDirection.Input objSqlClient.ExecuteNonQuery(SP_CustSave, objSqlParam(0).Value,objSqlParam(1).Value)) This last should be as below objSqlClient.ExecuteNonQuery(SP_CustSave, objSqlParam) when i do this i found error for could not cast <datatype> to <datatype> Weather i passed the objSqlParam array with values it works fine. Help me out on this. Regards, JaiPrakash Sharma Tag: How to put NULL into database column Tag: 143882
  - 8
    - OutPut Perameter with Microsoft.Practices.EnterpriseLibrary.Data Hi, I am using Microsoft.Practices.EnterpriseLibrary.Data as DataLayer in my project. I am facing problem to get OutPut Parameter in my Method which i am getting from my StoreProcedure. I am doing as below: Dim objSqlParam As SqlParameter() = Nothing objSqlParam = New SqlParameter(1) {} objSqlParam(0) = New SqlParameter("@CustId", SqlDbType.Int) objSqlParam(0).Direction = ParameterDirection.OutPut objSqlParam(0).Value = 1 objSqlParam(0) = New SqlParameter("@CustName", SqlDbType.Varchar) objSqlParam(0).Direction = ParameterDirection.Input objPIDataSet = objSqlClient.ExecuteDataSet(SP_CustSave, objSqlParam(1).Value) return Convert.ToInt(objSqlParam(0).Value.ToString()) Here i am not getting the Output Value from SP in Parameter, even though the SP is returning as i execute SP in Query Analyzer. Help me out on this. Regards, JaiPrakash Sharma Tag: How to put NULL into database column Tag: 143881
  - 9
    - Which protocol is used if not specified in connection string? Say you have a SQL Server connection string in the following format, where MySqlServer is a server connected a local network "data source=MySqlServer; Initial Catalog=MyDatabase; Integrated Security=FALSE; User ID=MyUserName; Password=MyPassword; Pooling=True; Connect Timeout=50" I am wondering what protocol (tcp, named pipes, etc.) would be used with a connection string in this format. If MySqlServer supports both named pipes and tcp, is the protocol indeterminant? Or is there a default protocol? BOL doesn't seem very clear about this. Tag: How to put NULL into database column Tag: 143880
  - 10
    - OleDbDataAdapter Fill - strange behavior All, If I do 2 OleDbDataAdapter Fills in a row, it does not work. I get a message saying that it cannot find the table I am looking for. Actually it is a Range in an Excel spreadsheet. I have tried closing the Connection and reopening it, but that makes no difference. Now here is the strange part, if I put a breakpoint (I am using C#) on the second Fill command, and then continue, it works!! I tried a 5 second delay between Fill commands, but that did not help either. Any thoughts? TIA, BIll Tag: How to put NULL into database column Tag: 143879
  - 11
    - Problem trying to update dbf table using VFPOLEDB.1 Provider Hi, I am new to using dbf files with .net. I have created a small program using visual web developer 2008. I am able to read a table using the oledb provider but if I try an update I get the famous cryptic "One or more errors occurred during processing of command" error.By the way I'm running vista home premium. The field (subtotal) I'm trying to update is type "N". It's been a while since I've used dbf tables so I apologize if any of my assumptions are stupid. I tried making "77.0" just "77" and a few other things. I downloaded Microsoft OLE DB Provider for Visual FoxPro 9.0 by the way. Here is the code; the error occurs on te executenonquery: Try Dim cn1 As New OleDbConnection( _ "Provider=VFPOLEDB.1;Data Source=C:\Users\Public;") cn1.Open() Dim cmd1 As New OleDbCommand( _ "Update OE Set SUBTOTAL = 77.0", cn1) cmd1.ExecuteNonQuery() Catch e As Exception MsgBox(e.ToString()) End Try Any help would be appreciated. Thanks, fig000 Tag: How to put NULL into database column Tag: 143874
  - 12
    - Code for ADO.NET: The Complete Reference Hello All. I am trying to use ADO.NET: The Complete reference by Michael and Denielle Otey . I wanted to download the code from the publisher's (Osborne) website BUT when I go to the Osborne website and enter this title into the "Search For" space, it says it cannot find that book. I suppose it is because it is several years old. I am trying to use the "Finding a Record in the DataTable" on page 366. Would anyone have the Code to this Book and be willing to email it to me? jimrichards@satx.rr.com If you do, it will be very helpful to me because I make too many mistakes when I copy code from a book. Thanks in advance for any help on this. Jim Tag: How to put NULL into database column Tag: 143860
  - 13
    - Code for ADO.NET: The Complete Reference Hell All. I am trying to use ADO.NET: The Complete reference by Michael and Denielle Otey . I wanted to download the code from the publisher's (Osborne) website BUT when I go to the Osborne website and enter this title into the "Search For" space, it says it cannot find that book. I suppose it is because it is several years old. I am trying to use the "Finding a Record in the DataTable" on page 366. Would anyone have the Code to this Book and be willing to email it to me? jimrichards@satx.rr.com If you do, it will be very helpful to me. Thanks in advance for any help on this. Jim Tag: How to put NULL into database column Tag: 143854
  - 14
    - syntax problem All, I have a C# app that is accessing an Excel spreadsheet using the following: OleDbDataAdapter metricDataAdapter = new OleDbDataAdapter("SELECT * FROM [ReqReviewsData]", Connection); This works, and I can read the ReqReviewsData range into my dataset. Now I am trying to write the dataset (or anything for that matter) back to the Excel spreadsheet. I do the following (taken from an example supplied by David Hayden): dbCmd = Connection.CreateCommand(); dbCmd.CommandText = "Update [ReqReviewsData] Set Space = \"xx\" WHERE MetricName = \"Verified\""; dbCmd.ExecuteNonQuery(); This generates the following: Syntax error in UPDATE statement. The connection string looks like: string ConnectString = "Provider=Microsoft.ACE.OLEDB.12.0;" + "Data Source=D:\\LETB\\Documentation\\Metrics\ \LETBMetrics.xlsm;" + "Extended Properties=" + (char)34 + "Excel 12.0;HDR=YES;" + (char)34; And yes indeed the Excel range that I am selecting has a column with "Space" and "MetricName" which really should not have anything to do with syntax anyway. I have diddled with dbCmd.CommandText in several ways, one of which is the following: dbCmd.CommandText = "Update [ReqReviewsData] Set Space = " + (char)34 + "xx" + (char)34 + " WHERE MetricName = " + (char)34 + "Verified" + (char)34; The produces the same error. What oh what is wrong with my UPDATE statement? TIA, Bill Tag: How to put NULL into database column Tag: 143851
  - 15
    - varchar(max) - SqlParameter I'm wondering how should I set up SqlParameter in order to pass varchar(max) type values. http://msdn2.microsoft.com/en-us/library/bb399384.aspx suggests using "-1" as value for SqlParameter's size. so: command.CommandText = "select len(@p)"; command.CommandType = CommandType.Text; SqlParameter p = New SqlParameter("@p", SqlDbType.VarChar, -1); p.Value = new String('a',10); command.Parameters.Add(p) After this code is executed several times (with "@p" parameter holding string of different lengths), it appears that this query is present in the sys.dm_exec_cached_plans view multiple times (each cache item is stored for concrete @p parameter length). It seems that: - when using 0, -1 or simply not providind Size for SqlParameter, it's size is calculated from parameter value. - if it is above limits (4000/8000), the parameter gets VarChar(MAX) type - otherwise, parameter gets concrete VarChar(size) type. - in order to make query optimizer reuse cached query plan, datatypes must match (including size...). So - back then - how to setup SqlParameter in order to pass VarChar(MAX) values correctly? -- Marcin Tag: How to put NULL into database column Tag: 143848
  - 16
    - What is the fastest way to update all rows of a table in a dataset Hello and thanks for your help :) I have uploaded an xml into a dataset so now it contains a single table filled with the xml values. I need to update one of the fields in all the rows with a constant value. What is the fastest way of doing it Btw: I don not have a database to which I can save the table and then execute an update command. Any ideas? Tag: How to put NULL into database column Tag: 143846
  - 17
    - Any way to make OleDb read an Excel file? With Visual Studio 2005 SP1 and DotNet Framework 2 SP1, Excel 2003 can read a file that was saved by Excel 2003, but the OleDb driver can't. Example: Excel row 2 maps to row 1 in OleDb, and Excel columns 1 to 24 (A to X) map to columns 0 to 23 in OleDb. Counting these in OleDb, row 1 columns 0 to 4 are OK, columns 5 and 6 get corrupted to DbNull, columns 7 to 12 are OK, columns 13 and 14 get corrupted to DbNull, etc. If I do Interop to Excel 2003 instead of using OleDb, it works. Counting these in Excel interop, row 2 columns 1 to 24 are entirely OK. Back to the OleDb problem. One worksheet has 40 columns instead of 24. The worksheet with 40 columns works. Several of the additional columns read as doubles instead of text but ToString() works on them. But all of the 24-column worksheets get corrupted by OleDb, and the corrupted column numbers vary. Does anyone know how to get OleDb to work? OleDbConnection connection = new OleDbConnection( "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + fileName + ";Extended Properties='Excel 8.0;HDR=NO'"); connection.Open(); DataTable schemaTable = connection.GetSchema("Tables"); DataRow[] schemaRows = schemaTable.Select(); foreach (DataRow schemaRow in schemaRows) { string tableName = schemaRow["TABLE_NAME"].ToString(); OleDbDataAdapter dataAdapter = new OleDbDataAdapter( "SELECT * FROM [" + tableName + "]", connection); int headerRowNum = 1; DataTable dataTable = new DataTable(tableName); dataAdapter.FillSchema(dataTable, SchemaType.Source); DataColumnCollection dataColumns = dataTable.Columns; int columnCount = dataColumns.Count; foreach (DataColumn dataColumn in dataColumns) { dataColumn.DataType = typeof(string); } dataAdapter.Fill(dataTable); int rowCount = dataTable.Rows.Count; if (!((rowCount > headerRowNum) && ((columnCount == 24) || (columnCount == 40)))) { dataTable.Dispose(); dataAdapter.Dispose(); continue; } DataRow headerRow = dataTable.Rows[headerRowNum]; // ... examine tableName in the debugger; it is correct including $ ... // ... examine headerRow in the debugger; some elements are null ... string x = (string)headerRow[5]; // crashes Using Odbc, besides the obvious changes to the DotNet class names and the connection string, one more change is this: int headerRowNum = 0; instead of int headerRowNum = 1; The reason of course is that HDR=NO in Odbc means HDR=YES. So with those changes, I read the Excel file in Odbc instead of OleDb. The corruption in Odbc is identical to the corruption in OleDb. Does anyone know how to get either OleDb or Odbc to read an Excel file? I think I have more news though. Although Excel 2003 saved the .xls file, now I guess that Excel 97 or 2000 or XP first created the .xls file. Here's the reason: In all of the cells which I'm trying to interpret, either the cell value was alphabetic, or the cell value had an apostrophe followed by digits, so the cell values were already text. For some other cells, Excel 2003 displays them with a little triangle in one corner, and a tooltip explains that the cell is text due to one of those reasons. However, for the cells which I'm trying to interpret, Excel 2003 doesn't display that triangle ... at first. However, if I put the mouse cursor in one of those cells and double-click, but do not type anything, and then move the mouse cursor to another cell and click, then suddenly Excel 2003 displays that little triangle in one corner of the cell that I double-clicked, and a tooltip explains that the cell is text due to one of those reasons. Furthermore, if I hit Ctrl+S to save the file, then suddenly OleDb starts correctly reading the cell that I double-clicked. So, was there a bug in Excel 97 or 2000 or XP, which corrupted the format when saving some cells which were text due to having apostrophe plus digits, but which saved some other cells correctly? And Excel 2003 contains a hack to read corrupted .xls files correctly? But OleDb is missing that hack so it gets all confused when reading files which were saved by Excel 97 or 2000 or XP (or saved by Excel 2003 without having double-clicked a corrupted cell)? Is there some way to get the same hack copied into OleDb so it will start working? Tag: How to put NULL into database column Tag: 143843
  - 18
    - Problem connecting to SQL Hello, I have several ASP.NET 2.0 sites That connect to a SQL 7 database. Up untill a few days ago they had been functioning just fine . For some reason all my SQL connections are returning the following error sporaticly: ---------------------------------------------------------- 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) ---------------------------------------------------------- This is not happening all the time but there have been an unusual amount of these errors as of late. I have searched the we web but so far I have been unable to find any documentation about this error that relates to SQL 7. Any help would be appreciated. -Scott Tag: How to put NULL into database column Tag: 143837
  - 19
    - Locating record on form by key Hi I have a winform db app that I have created by dragging fields on the form i.e. code has been generated by vs2008. How can I locate a record on the form by the record id? Many Thanks Regards Tag: How to put NULL into database column Tag: 143836
  - 20
    - DefaultValues I currently have some trouble with DataSets and DefaultValues. I have a DB on an MSSQL2000 Server with a table that contains several Columns with default values - e.g. defined like CREATE TABLE tbl_A ( [AGUID] uniqueidentifier ROWGUIDCOL NOT NULL CONSTRAINT [DF_tbl_A_AGUID] DEFAULT (newid()), [hidden] [bit] NOT NULL CONSTRAINT [DF_tbl_A_Hidden] DEFAULT (0) ) I did use the assistent to create a new data source for my project based on that DB. Unluckely the defaultvalues are not fetched from the DB. I could understand, that newid() was not fetched since it's a function - but at least the 0 should be set. Can anybody help me on how to get the DefaultValues from the DB into the DataSet? Tag: How to put NULL into database column Tag: 143832
  - 21
    - Faster .Compute() I have a class library that does calculations (usually AVERAGE) on (sometimes) large sets of data. The nature of the application is that it normally does several calculations (5-50 or more depending on user requests) on the same set of data, so the basic implementation is that I grab all the data out into a DataTable and then the library takes arguments and uses the .Compute() method of the DataTable to return results. In most cases, I'm doing an average of a column on a subset of rows. Subsequent calls do averages on different subsets of rows. This all works fine until the DataTable grows to 10k+ rows. Once I pass that threshold (or thereabouts), the performance goes into the toilet. It can literally take minutes to pull reports that would take < 10 seconds on a dataset half the size. The problem is that I don't want a single request to result in 50+ queries to my database, yet I must do 50+ calculations. I can add application servers pretty easily, but I only have the 1 database server. That's my scarce resource so I want to minimize his work (even though he's better at doing aggregation that my app server) and put my app servers to work. I am well aware of the limitations of the DataTable and I am also well aware that if I run these same queries directly against the database, I get much better performance (orders of magnitude better). I'm just not sure how to overcome this. So my question is how can I pull out possibly large sets of data and do calculations on the application servers so as not to overload my database server but avoid this huge performance penalty that I get when working with large DataTables? I'm willing to give up some performance for smaller sets of data if necessary (the tradeoff would be worth it, I'm sure, if I can figure out how to optimize the top end). I have a small benchmarking application that I'm working with and I have yet to find any method that out-performs DataTable.Compute(). I'm working under the assumption that I need to start w/ a DataTable because I will need to access the data several times (maybe I'm hosed right there - that's why I'm asking this question). Here is what I've tried thus far: 1) Manually call DataTable.Select() and get a DataRow[] object - brute force iterate and do the average 2) Use LINQ against an EnumerableRowCollection<DataRow> pulled from the DataTable and call .Average() 3) Brute force iterate over the DataTable myself and do the average 4) Call DataTable.CreateDataReader() and brute force iterate on the DataReader to do the average Of all of these methods, #1 results in the closest performance numbers to .Compute() (and it's pretty darn close) and #2 results in the worst (almost twice as bad) with #3 & #4 falling solidly in the middle of those two. Does anyone out there have an idea on how to solve this problem? Many thanks - Paul Prewett Tag: How to put NULL into database column Tag: 143831
  - 22
    - Renaming Excel Worksheets via ADO.NET I've written a program to extract information from Excel Worksheets over ado.net and most of it's working fine. Is there a way to change the sheetname via ado.net? Tag: How to put NULL into database column Tag: 143829
  - 23
    - Updating data adapters Hi I have several data adapters on my form. My question is, would a statement like Me.TableAdapterManager.UpdateAll(Me.MyDataSet) update all adapters or do I need to update each adapter individually? Thanks Regards Tag: How to put NULL into database column Tag: 143823
  - 24
    - Accessing data adapter in a dataset Hi I am trying to access the data adapter for a table in a dataset as below; MyDataSet.MyTable.Clear() MyDataSet.MyTableTableAdapter.Fill(MyDataSet.MyTable) But I am getting a 'MyDataSet.MyTableTableAdapter' is not a member of 'MyDataSet'. What is the problem and how can I access the underlying data adapter for the table MyTable? Thanks Regards Tag: How to put NULL into database column Tag: 143821
  - 25
    - Which is more expensive? Which is more expensive? Trapping an Exception to prevent duplicate entries in a database, or using IF EXISTS in T-SQL? Also, how would I go about testing which is more expensive myself? Thanks Tag: How to put NULL into database column Tag: 143817
- Next
  - 1
    - Performance implication of Parameters Hi. I was recently talking to a colleague who uses SQL Server as a backend to his applications. He mentioned that adding parameters causes SQL Server to determine the datatype and can cause performance issues, unless you explicitly specify the datatype. Does this also apply to Oracle, and if so, how can I specify it? Right now I am doing the following: int a = 4; String b = "test"; DateTime today = System.DateTime.Today; String sql = "insert into something (a, b, c) values (:a, :b, :c)"; OracleCommand aCommand = ... using above sql ... aCommand.Parameters.Add("a", a); aCommand.Parameters.Add("b", b); aCommand.Parameters.Add("c", c); Is there another way I could be doing this that would speed things up? Tag: How to put NULL into database column Tag: 143805
  - 2
    - How can I update a an entire table in a dataset? Hello, any help will be appreciated :) I have a dataset filled with data from a database table. Now I want to do an update command that will effect all rows in a specified table in this dataset (something like: "UPDATE TableName SET RowName = RowName + 10") How can I do it without executing it individually for each row? Thanks. Tag: How to put NULL into database column Tag: 143800
  - 3
    - TableAdapter and IN Statements Hi, I'm trying to configure a TableAdapter with an SQL statement fo the form: Select * from SomeTable where ID IN "1,2,3,4"; Can I do this with a tableadapter? Thanks in advance for your help! Terry Tag: How to put NULL into database column Tag: 143788
  - 4
    - insert many rows from tableadapter (vb2005) I have to insert a lot of rows from a tableadapter to a sql table. The operation is slow because table adptert send a single insert command for each row. Is there any way to have it with only one batch command? Or a faster solution? Thank you Alessandro Tag: How to put NULL into database column Tag: 143783
  - 5
    - Refilling dataset without changing context Hi I have a winform db app that is "bound" to a dataset...via data adpater, binding source and all that. As this is a multi-user app I need to refill dataset from time to time so the newest data is available for user to view. My problem is that I a) do not wish the app to become unresponsive while re-fill is being performed so need to do it as background task if possible. b) do not want the record context to change for user so user does not notice any disruption. My question is, are the above possible? If so, how? If not what is an alternate strategy? Thanks Regards Tag: How to put NULL into database column Tag: 143769
  - 6
    - Adding New Row, Set Value Hi, I am using the BindingNavigator control on my WindowsForm. When I click the '+' button, it appears that the program automatically adds another row to the datatable in the underlying typed dataset - fine. I need to set the value for one of the columns programmatically. How do I reference this newly created row? This must be done before I call Update to send it to the database. Private Sub bnEmploymentAddNewItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bnEmploymentAddNewItem.Click ??? = iPersonID End Sub Can someone help me with the syntax for referencing this newly created row so that I can set the value for the column? J Tag: How to put NULL into database column Tag: 143745
  - 7
    - Access to vb.net converter Hi Has any one checked this access to vb.net converter? http://www.microtools.us/anetvb7.aspx Any good? Thanks Regards Tag: How to put NULL into database column Tag: 143729
  - 8
    - System.Threading.ThreadAbortException: Thread was being aborted Hi, I am importing a flat file into a remote database using ADO.NET. First, I use a dataadapter to load the contents of the flat file into a datatable. Then, I use SqlCommandBuilder to update the data into a database table. I am doing this in development so the file and the script are local, while the database is remote. The flat file is only 16,236 rows, which I didn't think would be any trouble. But on the first run it thew this error: System.Threading.ThreadAbortException: Thread was being aborted. Each time I run it now, it imports fewer and fewer rows, until the last time, it only imported about 800 before it bombed out threw this error. I've updated the time outs in the .config files and in IIS. No change. If I limit the original select to 100 rows, it works fine. It seems like a timeout, yet it does not give a time out error. Any ideas? Thanks, Casey Tag: How to put NULL into database column Tag: 143728
  - 9
    - Getting connection information from vs 2008 generated code Hi I have developed a winform db app by dragging fields onto a form in vs 2008 i.e. I have not written code to open db connection myself and instead have let vs 2008 generate that code under the hood automatically. My question is, is there a way to get a handle to the db connection created by vs 2008? Thanks Regards Tag: How to put NULL into database column Tag: 143727
  - 10
    - Opening Access db via DAO in vb.net Hi In my vb.net app I am trying to open a db via DAO as below; Imports dao Dim dbSynch As dao.Database dbSynch = DBEngine(0).OpenDatabase("C:\MYDB.MDB") The problem is that on the last line I am getting the error 'DBEngine' is a type and cannot be used as an expression. What am I doing wrong? Many Thanks Regards Tag: How to put NULL into database column Tag: 143726
  - 11
    - Parameterised query with an ms access table Hi When using sql server, I can use a sql like below in my data adapter to send the sql a parameter value; SELECT <field list> FROM <table> WHERE Fieldx = @Para1 My question is, can I do something similar with an access db ie can I send a parameter to a data adaptor sql which is connected to an ms access table? If not is there another way to do this? Thanks Regards Tag: How to put NULL into database column Tag: 143717
  - 12
    - T-SQL Return row affected count in CLR proc? Is there a way to say to the caller just like an Insert/update/delete command would do from a T-SQL CLR Stored Procedure how many rows my procedure affected? I know I can push text down the SqlContext's Pipe as messages but how do you say here is my rows affected count? thanks! Tag: How to put NULL into database column Tag: 143706
  - 13
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  - 14
    - Total newbie, getting error "Reference to a non-shared member requires I'm trying to jump start with VB.Net/Ado.Net to get something done at work. I'm using the book "Programming Microsoft ADO.Net 2.0". One problem with this book is that his sample code does not spell out the imports. Usually somewhere in the paragraphs or pages before, it says "This assumes you're importing blah.blah.blah." Well, I'm not finding the reference. I've used the Data Source Configuration wizard to create BisDataSet. It's blowing up on line 9, on "BisDataSet" saying "Reference to a non-shared member requires an object reference." Trying to look that error message up on the Microsoft gives me a generic definition and little to go on. Here's my code: Imports Microsoft.Office.Interop.Excel Imports Microsoft.SqlServer.Server Imports System.Data.SqlClient Imports System.Data 1 Module Module1 2 3 Sub Main() 4 5 End Sub 6 Sub write_Scorecard_RRTP() 7 8 Dim RRTPRowset As BisDataSet.RRTP_ScorecardRow() 9 RRTPRowset = BisDataSet.RRTP_Scorecard(0) 10 11 End Sub 12 End Module Tag: How to put NULL into database column Tag: 143683
  - 15
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  - 16
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  - 17
    - Oracle connection Fails Hi All, I have built a simple .Net console application. In which i am trying to connect to the oracle database by using Oracle data provider for .Net from ORACLE site and it works fine on my machine. I have installed the same on my main server but when i run this application from Our main server i am getting an exception. The exception is as follows. 'Oracle.DataAccess.Client.OracleException at Oracle.DataAccess.Client.OracleException.HandleErrorHelper(Int32 rrCode, OracleConnection conn, IntPtr opsErrCt x, OpoSqlValCtx* pOpoSqlValCtx, Object src, String procedure) at Oracle.DataAccess.Client.OracleException.HandleError(Int32 errCode, Oracle Connection conn, IntPtr opsErrCtx, Object src) at Oracle.DataAccess.Client.OracleConnection.Open() at TestODACWithWindows2000.Program.Main(String[] args)' I am not able to trace out the exact cause why it is failing from that server. While the oracle server is pingable from that server. My application is as follows using System; using System.Collections.Generic; using System.Text; using Oracle.DataAccess.Client; using System.Data.SqlClient; using System.Xml; using System.Data; using System.Xml.XPath; using System.Xml.Xsl; using System.IO; namespace TestODACWithWindows2000 { class Program { static void Main(string[] args) { Console.WriteLine("Opening........"); string ConnectionString = "Data Source=(DESCRIPTION=" + "(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=Host)(PORT=1521)))" + "(CONNECT_DATA=(SERVER=DEDICATED)(SID = SID)));" + "User Id=username;Password=password;"; OracleConnection ora = new OracleConnection(ConnectionString); try { ora.Open(); } catch (Exception ee) { Console.WriteLine("{0} Exception caught.", ee); Console.ReadLine(); } } } } Please help me out.. Its urgent. Tag: How to put NULL into database column Tag: 143666
  - 18
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  - 19
    - Trouble Using DataAdapter.Update() Hi, and thanks in advance for any help :-) From a high level, heres what I'm trying to do. I have a flat comma delimited file that I need to import into a database, but after some of the data is massaged and mingled with data in the destination table. So, I first import the flat file data into a dataset using one dataadapter and one dataset. Then, I use another dataadapter and dataset to import the current data from the eventual destination table. Then, I do the logic and place the resulting data into the *second* dataset. So far so good. Now, all I have left to do is update the database table with the new data. Easy, right? But I can't make it happen. I know it's a lot of code, but here's what I've got: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ' First, import the flat file data Dim TextConnectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _ "Data Source=" & "C:\Inetpub\wwwroot\GrandCentralCoupons\comissionjunction\" & ";" & _ "Extended Properties=""Text;HDR=Yes;FMT=Delimited;""" Dim TextConn As New System.Data.OleDb.OleDbConnection(TextConnectionString) TextConn.Open() Dim dad1 As New System.Data.OleDb.OleDbDataAdapter("Select top 5 * from cj.txt", TextConn) Dim dsSource As DataSet = New DataSet dad1.Fill(dsSource) TextConn.Close() dad1.Dispose() ' Verify that the data is corect by binding to a gridview for visual display GridView1.DataSource = dsSource GridView1.DataBind() ' Now, get the currentdata from the destination database table Dim dbConn As New SqlConnection(WebConfigurationManager.ConnectionStrings("GCC_Remote").ConnectionString) Dim dad2 As New SqlDataAdapter() dad2.SelectCommand = New SqlCommand("SELECT * FROM import_temp_cj2", dbConn) Dim cb As SqlCommandBuilder = New SqlCommandBuilder(dad2) dbConn.Open() Dim dsDestination As DataSet = New DataSet dad2.Fill(dsDestination, "temp_import_cj") ' verify the data is correct by binding to a second gridview for display GridView2.DataSource = dsDestination GridView2.DataBind() ' mix. mingle, manage the data form the two datasets '/* lots of code snipped for easy of viewing */ ' verify the new data is correct by binding to a third gridview for display GridView3.DataSource = dsDestination GridView3.DataBind() ' update the database table dad2.Update(dsDestination, "temp_import_cj") '<--- NOT WORKING!!! dbConn.Close() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ All three gridviews display exactly what they should be displaying. No errors at compile or runtime. But, the new data just never makes it into the db table. I have a hunch I am missing something really simple... but I can't pick it out. This is the article I am using as a guide: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemdatasqlclientsqlcommandbuilderclasstopic.asp Thanks! Tag: How to put NULL into database column Tag: 143659
  - 20
    - Vengadeshwaraa Astrologers Vision To be the leader in the field of Astrology, to be the best Astrological service providers and to be ranked as the pioneer Astrologer in the world. To deliver various aspects and knowledge bases of Sri Lanka to the whole world and to be the Astrological force that binds all human beings together, wherever they be. Mission To become an Astrologically meaningful resource and be a vital part of lives of our members and users. Providing efficient & trusted service 24 hrs a day, 7 days a week. Our endeavor has become fruitful in making solutions for users to shop on line with direct delivery facilities while offering you the opportunity to know yourself, to grow and to improve your life. Shree Vengadeshwaraa Astrologers founded on 08th April 1972 has since gained numerous audience due to the untiring efforts by us and we believe that no other Astrology service can provide you with the value that Vengadeshwaraa can. So much so, our service is backed by an unconditional guarantee.We have predicted thousands and thousands of horoscopes and have never failed.We want this science to be taken to all mankind irrespective of religion. This is based on mathematical calculations and in no way concerned to the religion. We provide a pleasant, satisfying and superior Astrology experience to our customers while protecting their privacy and security. Shree Vengadeshwaraa Astrologers consist of Sri Lankan and Indian Astrologers and count over 35 years of dedicated and friendly service out of which 20 years has been spent on research alone.We have a very eminent team of Astrologers who are well educated and traditionally inherited this divine/legendary art of science.Our Astrologers are not only educated but also traditionally qualified. Our Astrologers are supposed to be best in this profession. Shree Vengadeshwaraa Astrologers has 03 branches worldwide namely, Sri Lanka, India and Germany. Head of Sri Lanka branch Brahmashree V.S.Sharma is a very popular Astrologer in Jaffna, Sri Lanka Head of India branch Padmanaapa Saastrikal Head of Germany branch Brahmashree V.Mahadeva Sharma Our consultant service to International customers are absolutely free of charge. We have geared ourselves to launch our new branches in London, Canada, Singapore, Malaysia and Australia next year. Shree Vengadeshwaraa also offers services in the field of Matrimonial, Hindu Religion Development and Hindu Brahmins social network. We take pride in our endeavour for the introduction of "TOP 100 ASTROLOGERS RATING PROGRAM" for the first time. Visit vengadeshwaraa.com Please take some time to get to know us better through the links that we have provided on this page and enjoy very competitive product price, special promotions and of course 100% satisfaction on accurate calculation of Horoscopes. Our Astrological and sincere thanks for visit Now:http:// www.vengadeshwaraa.com Tag: How to put NULL into database column Tag: 143658
  - 21
    - Insert c# DateTime object to Oracle Table using OleDbDataAdapter I have a table defined as: create table product_price ( productId int, price number(20,10), price_date date, primary key (productId) ); I am reading through a price file in c# and I would like to insert a row into the table for every price+date+productId combination. I am using the DataAdapter insertCommand and Table.Rows.Add(newRow) method but it fails when setting the date of the new row. // Setting the insert command priceDA.InsertCommand = priceDA.SelectCommand.Connection.CreateCommand (); priceDA.InsertCommand.CommandText = "insert into product_price (productId, price, price_date)" + "values (@productId, @price, TO_DATE('@priceDate', 'YYYYMMDD'))"; // Adding the row private void addPriceRow (int prodId, decimal price, DateTime priceDate, DataTable priceTable) // priceDate and other params defined elsewhere DataRow newPriceRow = priceTable.NewRow(); newPriceRow["productId"] = prodId; newPriceRow["price"] = prodPrice; newPriceRow["price_date"] = priceDate; priceDA.Update(priceDS, "product_price"); // Dies here with an oracle error ORA-00936 missing expression priceDS.AcceptChanges(); I think this is some sort of date format error, so I tried: newPriceRow ["price_date"] = priceDate.ToString("yyyyMMdd"); but that line fails at runtime with: "String was not recognised as a valid DateTime" Any ideas how I can save this date to the table? Many thanks in advance. -- JohnH Tag: How to put NULL into database column Tag: 143657
  - 22
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    - SQL CLR Sproc isn't running right I have a stored procedure for SQL Server 2005 which is done with the CLR... when its executed as a admin it works. when its executed as a non-admin it doesn't work... any ideas? the user has permission to execute the procedure on the server... seems to be something with the .NET SPROC's that is going wierd Tag: How to put NULL into database column Tag: 143652
  - 24
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  - 25
    - Error Messages? Currently, I tend to return @@ERROR in my stored procedures so that the calling code can test for error conditions. But I'm wondering: When @@ERROR is non-zero, is there a way for ADO.NET to detect any specific error messages? Thanks. -- Jonathan Wood SoftCircuits Programming http://www.softcircuits.com Tag: How to put NULL into database column Tag: 143638

Hi,

I have a stored procedures that takes few parameters( lets say 2).
Parameters are value for particular columns.

A column of type "binary' can contain "null".

I want to update a row, so that first column will have some value and second
should contain null. How can I do it?

MyParam.Value = null;
cmd.Parameters.Add(MyParam); // obviously doesn't work

Thanks,
Lubomir

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Re: How to put NULL into database column by Misbah

Misbah
Fri Feb 08 12:15:11 CST 2008

Try
MyParam.Value = DBNull.Value

--
Misbah Arefin

"Lubomir" <Lubomir@discussions.microsoft.com> wrote in message
news:66CA2DD4-E242-4A3F-9D45-8D427F1844E0@microsoft.com...
> Hi,
>
> I have a stored procedures that takes few parameters( lets say 2).
> Parameters are value for particular columns.
>
> A column of type "binary' can contain "null".
>
> I want to update a row, so that first column will have some value and
> second
> should contain null. How can I do it?
>
> MyParam.Value = null;
> cmd.Parameters.Add(MyParam); // obviously doesn't work
>
> Thanks,
> Lubomir
>

Top

Re: How to put NULL into database column by Lubomir

Lubomir
Fri Feb 08 12:52:01 CST 2008

Thanks,

Lubomir

"Misbah Arefin" wrote:

> Try
> MyParam.Value = DBNull.Value
>
> --
> Misbah Arefin
>
>
> "Lubomir" <Lubomir@discussions.microsoft.com> wrote in message
> news:66CA2DD4-E242-4A3F-9D45-8D427F1844E0@microsoft.com...
> > Hi,
> >
> > I have a stored procedures that takes few parameters( lets say 2).
> > Parameters are value for particular columns.
> >
> > A column of type "binary' can contain "null".
> >
> > I want to update a row, so that first column will have some value and
> > second
> > should contain null. How can I do it?
> >
> > MyParam.Value = null;
> > cmd.Parameters.Add(MyParam); // obviously doesn't work
> >
> > Thanks,
> > Lubomir
> >

Top