DataTable versus DataSet

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- Previous
  - 1
    - Scalar vs Reader Exec Method Hi Is there any advantage of using scalar execution method for data adapter if the result is going to be a single record? Thanks Regards Tag: DataTable versus DataSet Tag: 145193
  - 2
    - Table name to table adapter Hi From a reference to a data table in a dataset can I reference the data adapter associated with the table to execute data adapter's merge method? Thanks Regards Tag: DataTable versus DataSet Tag: 145192
  - 3
    - LinqDataSource Adding Row I have a gridview which I extended to allow adding rows. The extended gridview hooks into the ObjectDataSource's Selected event. In the event I add a new row to the List<T> returned by the ObjectDataSource select method. Thus when the grid gets loaded it now has a empty row, which can be edited. OnObjectDataSource_Selected(object sender, ObjectDataSourceStatusEventArgs e) { Type typeList = e.ReturnValue.GetType(); //List<T> for a select statement Type typeObj = e.ReturnValue.GetType().GetGenericArguments()[0]; //<T> object ojb = Activator.CreateInstance(typeObj); //new T // insert the new T into the list by using InvokeMember on the List<T> object result = null; object[] arguments = { 0, ojb }; result = typeList.InvokeMember("Insert", BindingFlags.InvokeMethod, null, e.ReturnValue, arguments); } I went to modify the code to work with a LinqDataSource. Unfortunately, their is no default constructor for the Objects created by LINQ, so the CreateInstance method fails. Is their a way I can insert a new row with the LinqDataSource? thanks, Tag: DataTable versus DataSet Tag: 145191
  - 4
    - Connect without async but get timeout error when async=true Have an app deployed on a network. On some machines, a regular connection to the sql server establishes and works great, but the same exact connection string along with "Asynchronous Processing=true" gives a 'Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.' error. I know the timeout setting isn't the actual issue, and the client machine can demonstrate connectivity to the sql server manually (and like I mentioned, has no problem connecting without the async). Is anyone familiar with anything like this? Tag: DataTable versus DataSet Tag: 145190
  - 5
    - Internal .Net Framework Data Provider error 6 the following error is popping up too many times for my liking on a website that accesses mirrored databases. System.InvalidOperationException: Internal .Net Framework Data Provider error 6. at System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject) at System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection) at System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory) at System.Data.SqlClient.SqlConnection.Open() at dsOrderDataTableAdapters.QueriesTableAdapter.SetOrderCompleted(Int64 orderid) in Tag: DataTable versus DataSet Tag: 145189
  - 6
    - Dealing with DBConcurrencyException error in multi-table scenario Hi I am handling DBConcurrencyException for an adapter manager using code below. My problem is how to merge table in error with its copy from underlying database. If I need the table's data adapter for the merge, can I extract the data adapter at run time from the information I have viz adapter manager, dataset and the table in error. Thanks Regards Try Me.TableAdapterManager.UpdateAll(Me.MyDataSet) Catch ex As DBConcurrencyException For Each MyTable In MyDataSet.Tables If MyTable.HasErrors Then ' How do I merge MyTable with the database copy of itself here? End If Next End Try Tag: DataTable versus DataSet Tag: 145186
  - 7
    - Call stored procedure with table parameter Is it possible to call a stored procedure with a Table parameter? I see that the System.Data.SqlDbType enumeration contains a value called Structured, and the description in help says "A special data type for specifying struyctured data contained in table-valued parameters". But, I haven't figured out how to use this. Tag: DataTable versus DataSet Tag: 145185
  - 8
    - BindingSource.EndEdit() throws Exception Environment Information: I am running Visual Studio 2005 Version 8.0.50727.762 (SP.050727-7600) and connecting to a SQL Server 2005 database, although this problem never reaches the database. I am also using Windows XP Professional SP 2. My problem is that when I call the EndEdit() method for my BindingSource, I recieve the following error: System.ArgumentNullException: Value cannot be null. Parameter name: key Stack Trace: at System.ThrowHelper.ThrowArgumentNullException(ExceptionArgument argument) at System.Collections.Generic.Dictionary`2.FindEntry(TKey key) at System.Collections.Generic.Dictionary`2.get_Item(TKey key) at System.Data.DataView.MaintainDataView(ListChangedType changedType, DataRow row, Boolean trackAddRemove) at System.Data.DataViewListener.MaintainDataView(ListChangedType changedType, DataRow row, Boolean trackAddRemove) at System.Data.Index.<>c__DisplayClass5.<MaintainDataView>b__4(DataViewListener listener, ListChangedType type, DataRow row, Boolean track) at System.Data.Listeners`1.Notify[T1,T2,T3](T1 arg1, T2 arg2, T3 arg3, Action`4 action) at System.Data.Index.MaintainDataView(ListChangedType changedType, Int32 record, Boolean trackAddRemove) at System.Data.Index.InsertRecord(Int32 record, Boolean fireEvent) at System.Data.Index.ApplyChangeAction(Int32 record, Int32 action, Int32 changeRecord) 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, Exception& deferredException) at System.Data.DataTable.InsertRow(DataRow row, Int32 proposedID, Int32 pos, Boolean fireEvent) at System.Data.DataView.FinishAddNew(Boolean success) at System.Data.DataRowView.EndEdit() at System.Windows.Forms.CurrencyManager.EndCurrentEdit() at System.Windows.Forms.BindingSource.EndEdit() There is a BindingNavigator and DateTimePicker control bound to the BindingSource. The BindingSource is bound to a TableAdapter on a DataSet. The DateTimePicker is not likely to be a part of the problem because I also tried replacing it with a regular TextBox and the error still occurred. This problem occurs randomly. The application passed all testing and the error did not appear until the application was deployed. The error happens more often than not, but it does not always happen even using the EXACT same steps to create the issue. Please help! If you would like more details on how specific objects are bound, please let me know. Thanks! Tag: DataTable versus DataSet Tag: 145184
  - 9
    - Update datatable 1 with information from datatable 2 using an update I have 2 datatables in a dataset and i would like to update information in datatable_1 with some fields from datatable_2 using an update statement joining datatable_1 and datatable_2. Is it something that can be done? Thanks, Hetal. Tag: DataTable versus DataSet Tag: 145182
  - 10
    - Getting Information Schema values column_name,Allow nulls, primary Hi, In windows C# programming I have to bind Column name, Primarykey , Allow null of a table from the sql server using Information_Schema please give me suggestions. Thanks Senthil Tag: DataTable versus DataSet Tag: 145181
  - 11
    - adapter manager error handling Hi How can I handle errors in the UpdateAll method for adapter manager considering that it has multiple tables. Its probably easy by using try/catch if only one table has errors but what if more than one table have errors at update? Thanks Regards Tag: DataTable versus DataSet Tag: 145176
  - 12
    - Performance to copy blob from SqlDataReader I have a SqlDataReader dr returned from a SqlCommand. dr contains only one column of 2000 varbinary(max) records (contains 24 bytes in my testing case). The following code takes 1 second to run. I would like to improve the performance. Any suggestions while (dr.Read()) { list.Add(dr[0] as byte[]); } where list is of List<byte[]>. Tag: DataTable versus DataSet Tag: 145175
  - 13
    - Help with ADO.NET - Please.. I have a table A in Database with 5 columns. I have a CSV file with same structure as of table A. I need to compare these two table in ado.net after csv file is loaded into a datatable object. Can any body help me please.. Tag: DataTable versus DataSet Tag: 145170
  - 14
    - changing the connection for a strongly typed dataset How can I change the connection used by a strongly typed dataset? I have a strongly typed dataset which connects to a development database. I want to change the connection string for production to point to the production database. Thanks Bill Tag: DataTable versus DataSet Tag: 145168
  - 15
    - Oracle and .NET Hello, I have an SP, which is calling from .NET code using ODP. In that SP i have few update table statement followed by Insert statement and then delete statement. When I am executing its not updating the table. means the code flows are: Update <statement> Update <statement> Update <statement> Insert <statement> Commit Delete <statement> Commit In this scenario, update statements are not working. do i need to put commit after every update statement. Cheers, Prasanta Tag: DataTable versus DataSet Tag: 145165
  - 16
    - Oracle and .NET Hello, I have an SP, which is calling from .NET code using ODP. In that SP i have few update table statement followed by Insert statement and then delete statement. When I am executing its not updating the table. means the code flows are: Update <statement> Update <statement> Update <statement> Insert <statement> Commit Delete <statement> Commit In this scenario, update statements are not working. do i need to put commit after every update statement. Cheers, Prasanta Tag: DataTable versus DataSet Tag: 145164
  - 17
    - Problem with oracle transaction Hello, I have an SP, which is calling from .NET code using ODP. In that SP i have few update table statement followed by Insert statement and then delete statement. When I am executing its not updating the table. means the code flows are: Update <statement> Update <statement> Update <statement> Insert <statement> Commit Delete <statement> Commit In this scenario, update statements are not working. do i need to put commit after every update statement. Cheers, Prasanta Tag: DataTable versus DataSet Tag: 145163
  - 18
    - SqlParameter with size=0 I used the SqlDataAdapter Configuration Wizard to generate a new SqlDataAdapter. I used Sql statements and typed a simple "select * from table1" for the sql. In the generated code all the SqlParameters had size=0. WHY? I have done this in the past, very recently in fact, with no problem. I tried this on 2 different PCs and using different tables on different database servers. Same result. Tag: DataTable versus DataSet Tag: 145162
  - 19
    - TransactionScope and Concurrency? With the typical example of implementing calls that leverage TransactionScope (via a using code block) - would this be "safe" for asp.net web apps? I am finding some conflicting opinions on the net about this issue. Because transaction enlisting is inherent by all calls in the code that executes (within the using block), would User A's rollback cause User B's to rollback too if they both hit at the same time? Tag: DataTable versus DataSet Tag: 145160
  - 20
    - If I have a gridview with edit buttons, how do I show dropdowns in I have a gridview that allows the user to edit rows by clicking on an EDIT button for each row. I notice that in EDIT mode I get checkboxes for some fields, and textboxes for others. But I would like to have a dropdownlist in some cases. I would have to prefill that dropdown list with allowed values. How do I do that? Thanks, Marvin Tag: DataTable versus DataSet Tag: 145159
  - 21
    - Transaction Isolation Level Hello, Is the following code handled different in .NET 1.1 and .NET 2.0? public SqlTransaction BeginTransaction() { return this.BeginTransaction(IsolationLevel.Unspecified, null); } It seems that running this code and starting a transaction under 2.0 we run into locking issues if more than one transaction should be opened at the same time, while running on 1.1 there are no problems. Does it make a different to use IsolationLevel.Unspecified there? Any hint would be great. Thanks! Best Regards, Andreas Pfanner Tag: DataTable versus DataSet Tag: 145153
  - 22
    - Binding RadioButtonList to a SQL bit column through SQLDataSource Hi. This seems like it should be easy but its driving me nuts... I have a radio button list like so... <asp:RadioButtonList ID="controlName" runat="server"> <asp:ListItem Value="'True'" Text="Y" /> <asp:ListItem Value="'False'" Text="N" /> </asp:RadioButtonList> I have a SQLDataSource setup to insert this field into a microsoft sql table. The data source line for this field is... <asp:ControlParameter ControlID="controlName" Name="PARAM_NAME" PropertyName="SelectedValue" Type="Boolean" /> And my param in the sql stored proc is... @PARAM_NAME BIT The insert keeps failing however. It is passing in "True" or "False" to the bit param which I believe is the problem. I tried passing in "T"/"F", "1"/"0", etc.... but can't get anything to work. I believe what I need to pass in is a 1 or 0 (ints, not strings), however the way I understand it is the ListItem Value can only be a string. Is there a way to do this? Thanks! Tag: DataTable versus DataSet Tag: 145137
  - 23
    - Typecasting without knowing the cast Hi I have a data row variable which could be for any of a number of tables in my apps. How can I type cast the variable to correct type at runtime? I know I can get the type description using MyRow.ToString but don't know how to use this to typecast MyRow variable. I need this to write a generic SUB that can deal with rows of any table type. Thanks Regards Tag: DataTable versus DataSet Tag: 145135
  - 24
    - Provider Speakeasy Business DSL: 3 for Free DSL for your business - Order now and get free hardware, free installation, and a free month of service. Speakeasy also provides US- based, 24/7 support. Sign up today. http://www.ogogo123sina.cn/Dsl-Providers.htm Tag: DataTable versus DataSet Tag: 145132
  - 25
    - .NET Library for ORACLE backup & restore function Hi, i'm searching for a .NET library for backup & restore a ORACLE database simluar to 'Microsoft.SqlServer.Management.Smo'. Is that possible, i didn't found anything about this problem. Many thanks for any help Marco Tag: DataTable versus DataSet Tag: 145130
- Next
  - 1
    - Handling data update errors with multiple tables Hi Its easy to trap errors such as concurrency error when a single table is involved with code similar to this; Try Me.MytblAdpater.Update(DS.Mytbl) Catch dbcx As Data.DBConcurrencyException HandleConcurrencyException(dbcx.Row) End Try How does one handle concurrency exception with an AdpaterManager where multiple tables are involved in statement like; Me.TblAdapterManager.UpdateAll(DS) In particular how does one know which table or tables and row/rows are in error? Thanks Regards Tag: DataTable versus DataSet Tag: 145128
  - 2
    - How do you make a dataset when you cannot use a database for it? I have a challenge on my job: to make a gridview that depends on a dataset that is not from a database. The reason for this is that there are two gridviews plus some other data that have to be saved to a database all at once. To simplify a little, at the top of the form, the user enters two numbers which describe how many rows each grid has to have. (He also enters some other data). I guess he would click on a submit button once he has those numbers. Then he has to enter all the data in the all the rows for the 2 grids. The grid rows should have EDIT and DELETE buttons. At the end of all this, he enters a password and clicks on a submit button. Only after he does all this can I save the grid information (and the 2 numbers and the other data) to databases. So it seems to me that I can't have each grid with a datasource of a database, because it would be showing what it retrieves with its SELECT statement, which at the start of the data-entry would be no rows at all. The original setup I had was that the user would fill out a row of textboxes and checkboxes, and then he would hit a submit button, and the data would be added to a database, and the grid would reflect the new row added. I repeated this method for the 2nd grid. But I was told that I should have an all-or-nothing operation - either all the grids and other data are submitted (with a password), or nothing is. Is there a way to do this? Thanks, Marvin Tag: DataTable versus DataSet Tag: 145127
  - 3
    - Problem remoting to SQL Server from a Vista Machine I have a C# .net app that connects remotely to a SQL Server 2005 database on a Windows 2003 server machine sitting in Chicago. It connects through a VPN. Everything works fine when I run the app from a machine running XP Pro SP 2. When I try to run the same app, no modifications, from a Vista Business machine and from a Vista Ultimate machine, (so I am assuming it's a Vista issue) I get the error [DBNETLIB] ConnectionOpen (Connect()).] SQL Server does not exist or assess denied. It is not the SQL Server, because it works from the XP machine. It is not TCP/IP on the Vista machines because I can do everything else, connnect to internet, connect through VPN etc. As it is happening on more than one machine running Vista and not the XP, that is why I am assuming it is a Vista Problem. I can connect to the SQL Server on the Chicago machine by using SQL Server Management Studio Express. That seems to narrow it down to a ado.net issue. I am using the .net 3.5 framework. Any suggestions? BillG Tag: DataTable versus DataSet Tag: 145126
  - 4
    - cEldmDrxbyviKDBZ WEILPJ f81tpvn7894323ndrx Tag: DataTable versus DataSet Tag: 145125
  - 5
    - cEldmDrxbyviKDBZ WEILPJ f81tpvn7894323ndrx Tag: DataTable versus DataSet Tag: 145124
  - 6
    - Connect to BindingSource with DataMember I've tried to set a BindingSource DataSource property to a DataSet with many tables. Now I try to connect two DataGridView to the same BindingSource, but using two different DataMember (one with the name of one table and the other with another). Everything is working, the two DataGridView controls are rendering well. Everyone has its own cursor, I can change the data and all. The problem is that if I want to use the properties and methods of the BindingSource object I can't specify which table I'm referring to... For example, if I write bs.Position++; which cursor table is going to move? No one actually, as I have already tried...But why can't I specify the which table I want to manage from the BindingSource if the BindingSource is actually capable of working with multipled set of data? Am I supposed to use a single BindingSource object for each table of the database? Thank you for your help cold Tag: DataTable versus DataSet Tag: 145117
  - 7
    - Can this be made generic? Hi I have below code which updates table tblClients and handles concurrency violation if needed. Is there a way to make the code generic so for example another table's name can be passed to the SUB? Thanks Regards Private Sub UpdateDatabase() Try Me.tblClientsTableAdapter.Update(Me.ContactsDataSet.tblClients) Catch dbcx As Data.DBConcurrencyException HanldeConcurrency(dbcx.Row, ContactsDataSet.tblClientsRow) End Try End Sub Tag: DataTable versus DataSet Tag: 145107
  - 8
    - Add WHERE Clause Dialog Box Doesn't Support Object Source? When configuring a data source for the GridView, I can access the Add WHERE Clause dialog box, which allows me to filter the results based on a particular column's relationship to any of a number of different data sources (cookies, control, form, etc.). However, what I'd really like to do is tie it to a static property of one of my application's classes. Does anyone know why this option does not appear to be supported, or if there's any workaround? Thanks. -- Jonathan Wood SoftCircuits Programming http://www.softcircuits.com Tag: DataTable versus DataSet Tag: 145106
  - 9
    - null value in xml translates to empty string in dataset after ReadXML I am importing data in a XML document into a SQL Server database. Null data in the XML document is represented like this: <elementname /> But when I load the XML document into a dataset, it becomes an empty string, which generates an error when I insert the data into the database for datetime fields. I load the data into a XMLTextReader, read it into a dataset, and send it to the database: XMLTextReader xr = new XMLTextReader (filename.xml); DataSet ds = new DataSet(); ds.ReadXML(xr); SQLDataAdapter da = new SQLDataAdapter(); //configure InsertCommand... da.Update(ds); When I look at the data in the dataset, null values in elements become empty strings "". I get: "Failed to convert parameter value from a String to a DateTime." Tag: DataTable versus DataSet Tag: 145100
  - 10
    - Tableadapter record count Hi I am using the below statement; Me.MyTableAdapter.Fill(Me.MyDataSet.tblMyTable) How can I now check the record count of the data table and specifically if the record count returned by fill is not 0? Thanks Regards Tag: DataTable versus DataSet Tag: 145094
  - 11
    - Sample app Hi I am coming from a vba/access/vb database development background. I however find db development in .net daunting and have so far not been able to find a good example to learn how to do winform database apps in .net well. I am looking for example of a 1-many database app that is written well enough but purely in terms of being able to work in a multi-use environment of a relatively small number of users. If the example can avoid bells and whistles like WCF for the time being to for simplicity sake then great. I wonder if you have such an example in mind somewhere and can provide a link for that? I am on VS2008. Many Thanks Regards Yahya Usman Tag: DataTable versus DataSet Tag: 145092
  - 12
    - Excel and OleDbDataAdapter. How can i ignore blank columns Hi, I have an application, that needs to import excel spreadsheets into a SQL Server database. I am using an OleDBDataAdapter to load (fill) the data into a Dataset. This works fine, when the spreadsheet is formatted correctly. Occasionally, person sending us the file, will put the data starting in column B, not column A. This fails our checks on column count. They also have started in the third row, which messes up the column headings. I Get F1 -F6 for the column headers and only three of the six actual column heading are read in (as data). The other three column headings are read in as blanks. Also occasionally, an extra blank column after the data gets read in. Well it looks blank in the spreasheet, but I'm assuming they have done something to it. Is there an easy way for me to get the DataAdapter to ignore blank columns and rows? At the moment, I'm (in my opinion) quite rightly rejecting the file, but I would like my application to be more fault tolerant and intellegent. Rollasoc Tag: DataTable versus DataSet Tag: 145091
  - 13
    - BindingSources, BindingNavigators and direct navigation... Hi there: I dragged several fields from a Data Source to a form in the designer. It created several TextBoxes and a BindingNavigator bound to a BindingSource which DataSource is the DataTable containing those fields. Now I'm able to navigate through the table to next, previous, last, ... Here's the problem: I want the TextBoxes show a specific row in the DataTable, say a row with the Name field = "J Lo" (in a DataTable "People"), without having the user navigating through several rows up until he finds this one. How do I position the BindingSource to that specific row, if I don't know it's relative position in the DataTable bound to the BindingSource?. The DataTable doesn't have a CurrencyManager as the BindingSource does, and the BindingSource doesn't have a Find method to locate specific rows. Please help... -- Rafael Soteldo Tag: DataTable versus DataSet Tag: 145089
  - 14
    - TransactionScope and DataTables Here is the situation: A DataTable has contains rows with all rowstates in it. A Table Adaptor.Update is performed that is wrapped in a TransactionScope. An error occurs and the complete is not called. All is well on the Server, all rows are backed out. My DataTable is not so well. Some look like they have been updated and have a rowstate of unchanged. The rest of the rows starting with the first row that had an error have the rowstate they had from before the update. Does anyone have an idea of how to handle the data in the datatable after the rollback of the transaction? Tag: DataTable versus DataSet Tag: 145088
  - 15
    - Inserting into csv files using Jet and System.Data.OleDb I'm trying to insert data into a csv file using System.Data.OleDb but I'm unable to insert rows with character fields bigger that 255 characters. the code: const String INSERT_STATEMENT = "insert into [table#csv] (SmallStr, BigStr) values (@SmallStr, @BigStr)"; OleDbConnection oConn = new OleDbConnection("Provider=Microsoft.Jet.OleDb.4.0;Data Source=c:\\db\ \;Extended Properties=\"text;HDR=YES;\""); oConn.Open(); OleDbCommand oCmd = new OleDbCommand(INSERT_STATEMENT, oConn); OleDbParameter oParam = null; oParam = new OleDbParameter("SmallStr", OleDbType.VarChar, 255); oParam.Value = "0123456789"; oCmd.Parameters.Add(oParam); oParam = new OleDbParameter("BigStr", OleDbType.LongVarChar, 1024); oParam.Value = "012345678901234567890123456789012345678901234567890123456789012345"+ "678901234567890123456789012345678901234567890123456789012345678901234567890123"+ "456789012345678901234567890123456789012345678901234567890123456789012345678901"+ "23456789012345678901234567890123456789"; //260 characters oCmd.Parameters.Add(oParam); oCmd.ExecuteNonQuery(); The above does work if i change the BigStr param to 255 chars or less. I've tried playing around with putting status.ini files into the folder in various configurations but nothing seems to help. I'm hoping though that it is possible to get more than 255 characters into a text file using OleDb and Jet. If anyone could help me with this I would be very greatful, spent ages trying to get it right. Thanks in advance :-) Tag: DataTable versus DataSet Tag: 145084
  - 16
    - Limit rows in a DataView to those used in a relation with RowFilter? I have a simple DataSet with two tables, ParentTbl and ChildTbl. They each have a ChildId column. They are joined by a relation ParentTbl_ChildId which associates the ChildId column with ParentTbl as the parent and ChildTbl as the child. This DataSet is not based on a database (it is saved to and loaded from XML files) so SQL queries are not an option. I need a DataView on ChildTbl which is limited to those rows involved in a ParentTbl_ChildId relation. I have been trying to achieve this with the RowFilter property, but have been struggling to define the appropriate expression. Some of the variations I have attempted are: m_filteredView->RowFilter = L"NOT(NULL = (Parent(ParentTbl_ChildId1).ChildId1))"; //The view just ends up being empty m_filteredView->RowFilter = L"Count(Parent(ParentTbl_ChildId1).ChildId) > 0"; // Throws SyntaxErrorException with "Syntax error in aggregate argument: Expecting a single column argument with possible 'Child' qualifier." m_filteredView->RowFilter = L"ChildId IN(Parent(ParentTbl_ChildId1).ChildId1)"; //Throws EvaluateException with "Only constant expressions are allowed in the expression list for the IN operator." Is this even possible? Can anyone suggest an expression that might work? Tag: DataTable versus DataSet Tag: 145083
  - 17
    - DataGridView Hi All, I have been searching everywhere but I am totally stumped. Can anyone PLEASE help. I am using VB.Net 2005 edition and have a DataGridView (DGV)on my form. The DGV is NOT bound to anything as I want the user to input their values. Once they have finished I THEN want to save the values in the DGV to a MS Access table. How do I do this? My DataGridView is called DGV1 and my table is db1.mdb. I would KILL for any example code you may be able to pass my way. THANK YOU Tag: DataTable versus DataSet Tag: 145081
  - 18
    - Underscore ("_") prefix added to my Column Name I manually created a DataTable in a Typed DataSet using the DataSet designer in VS 2008 Pro. One of the Column names is "IN". When referencing this table in VB.Net 2008, the IntelliSense did not show the column "IN" but it did show a column "_IN'. If I tried to reference this column in code using "tablenameRow.IN" I got the build error: "'IN' is not a member of 'app.DataSet.tableRow". If I reference it with "tablenameRow._IN" then I don't get the build error. I have several other 2-letter-capitalized column names in this table such as: "'LT', 'PI' and 'MA'". These other column names show up in intellisense and can be referenced without the "_" prefix. Can someone tell me what's going on? Thanks -- Robert Scarborough Integrated Visual Systems Tag: DataTable versus DataSet Tag: 145076
  - 19
    - Trapping nulls for SequetialAccess I have a group of records in a set - usually 5-10 rows. For example ProviderPanel would have several elements. I do this so I can handle the formatting of each value on a case by case basis. A typical scenario would be that before writing any records to either labels or a class, I should try to 'trap' any possible nulls before trying to set them to a variable. This only works with SequentialAccess in a DataReader So, cn.Open() dr = cmd.ExecuteReader(CommandBehavior.SequentialAccess) Do While dr.Read Select Case strGroupLevel Case "PCP" strMeasure = iif( dr("MeasureID") is DBNull.Value, "", (dr("MeasureID") lPerform = iif(isnumeric(dr("Perform"), dr("Perform"),0) Case "......." End Select But if I do this --- I get the ordinal error - "Tryinng to read from ordinal 1 ...etc. I suppose this is because I am doing a 'double-take' on the column with my IIF statment? And it can't read it because it's on to the next column already? Anyhow, how can I go about trapping nulls if I use SequentialAccess in a Reader. Tag: DataTable versus DataSet Tag: 145073
  - 20
    - ado.net entity framework newby question Hi, I have downloaded and installed beta 3 of Ado.net entity framework and played with this a little bit and it's quite cool - I can query the database and get the objects etc. The only thing I can't dig to is how to actually create custom attributes in the classes that the framework has generated for me. For example, say, I have a simple table: UserId, UserName, UserAge and I want a custom properry, say, IsOld that will be calculated at runtime, something like public bool IsOld{ get{ if (UserAge > 90){return true;} else {return false;} } } how do I do this? Thanks for all your comments! Tag: DataTable versus DataSet Tag: 145072
  - 21
    - Direct navigation to specific rows in a DataSource... Hi there: I need to get the position of a given Row to navigate directly to it, in a form that has a BindingNavigator and several TextBoxes showing each rows details... I dragged the fields from the Data Sources window to the form in the designer, which created the BindingNavigator attached to a BindingSource. As far as I know, the BindingSource lets you move to the first, next, to a position, previous and last row of a DataTable, so, what if I need to navigate directly to a row that has a specific value in a field (for instance, "Carl" in the field "Name" in the DataTable "People"). I suppose I should get the row position within the DataTable attached to the BindingSource, and then set the BindingSource.Position to that position. But how ca I do that?, the DataTable doesn't expose a property that shows the relative position of each row in the table. Moreover, what if the DataSource is a DataView with filters set, how do I get the position of that given row within this DataView? Please, need help... Thanks in advance..., Rafael Soteldo Tag: DataTable versus DataSet Tag: 145068
  - 22
    - LINQ with Datetime Hi, How can I use a date string to test a date in a LINQ query. Below is a query in Northwind Many thanks for any help Ant NorthwindDataContext db = new NorthwindDataContext(); var resultSet = from o in db.Orders where o.OrderDate >= Convert.ToDateTime("20080601") select o; Tag: DataTable versus DataSet Tag: 145066
  - 23
    - OleDb delays commits and unlocks? I've seen other posts with similar problems, but no solutions. I have two hair-pulling dilemmas that have been frustrating me for months now. Is there no solution? (C#.NET, Framework 2.0, Jet OleDb 4.0) The general goal is to read one MDB file and copy relevant info into another MDB file (copied from an empty template), replacing the old file with the new file. DataAdapters are used only to read (or re-read) the data from the file into the in-memory DataTable. All data INSERTs and UPDATEs are done with OleDbCommand.ExecuteNonQuery(). Problem 1: To retain the original version of the file, the process requires two rename operations. The first renames the original file. The second renames the new file to have the original file's name. Half the files I process do this OK. The other half fail on one of the renames, claiming that the file is still locked by another process. Checking the directory just prior to the rename attempt confirms that the corresponding LDB file still exists when the rename fails and doesn't exist when it succeeds. I've gone so far as to put all the data copying into a separate Main and invoking it with a Process.Start() so that the locking process has to be terminated before I attempt the rename. No dice. Aaaaargh! Problem 2: In the last-called method of the copy process, one new record is written to each of two empty tables. After that, a message is written to a log file, the method returns, and the OleDbConnection is closed. All of that occurs in about a dozen lines of code. This works almost all the time, except on one of my test files. With that file, the first inserted row appears in the output mdb file, but the second one does not! There is nothing particularly unusual about this file; other test files have identical structures. The tables involved are new tables, not present in the source data file, and every test file requires that these two rows be created. No errors are reported by the INSERTs or any other statement; it just doesn't get committed to the table. Double-Aaaaargh!! Tag: DataTable versus DataSet Tag: 145059
  - 24
    - Books recommendations please Hi I need to develop winform database applications and wondering is these two books will get me there; Data Binding with Windows Forms 2.0: Programming Smart Client Data Applications with .Net http://www.amazon.co.uk/Data-Binding-Windows-Forms-2-0/dp/032126892X/ref=wl_it_dp?ie=UTF8&coliid=I2L84GECRS6E6P&colid=399925I1FY0N8 Windows Forms 2.0 Programming http://www.amazon.co.uk/Windows-Forms-Programming-Chris-Sells/dp/0321267966/ref=wl_it_dp?ie=UTF8&coliid=I1RY8RDOG4LBP1&colid=399925I1FY0N8 I already have Bill's 'Hitchhiker's guide to VS and SQL Server'. Any additional recommendations would be appreciated too. Basically anything that will get me off your backs. Thanks Regards Tag: DataTable versus DataSet Tag: 145053
  - 25
    - typed dataset Hi all, I need to make a typed dataset cause i import a dataset from foxpro I use this code Dim oDbcommand As New SqlDataAdapter(Sql, Conn_SqlServer) oDbcommand.MissingSchemaAction = MissingSchemaAction.AddWithKey oDbcommand.Fill(Me.DataSet, Me.TableName) My Problem is vs 2005 or Framework 2.0 don"t return the well definition a numeric field (from sql server 2000) the xsl returned for the numeric Field <xs:element name="cli_pricemin" type="xs:decimal" minOccurs="0" /> for the string field <xs:element name="cli_email" minOccurs="0"> <xs:simpleType> <xs:restriction base="xs:string"> <xs:maxLength value="50" /> </xs:restriction> </xs:simpleType> </xs:element> I would like to have the maxlength and the decimal, for the numeric field , pricemini <xs:maxLength value="10" /> Have you an Idea ? Olivier Tag: DataTable versus DataSet Tag: 145047

Is there any performance difference between creating and filling a DataTable
and a single datatable dataset, or is it really the same thing under the
covers.

In other words, do you pay any overhead for

myDS = Create & Fill Dataset with single datatable
MyDT = myDS.Tables(0)

versus just creating DT directly as a datatable and filling it?

Re: DataTable versus DataSet by Patrice

Patrice
Wed May 07 06:26:15 CDT 2008

A dataset is basically a collection of tables. It's likely that most of the
cost will go into filling the table with data rather than in handling a
collection that has a single element. Use what makes sense for your
application. You could easily verify this if it doesn't seems obvious.

If you have a performance problem, IMO one of the first step would be first
to double check the query and in particular the amount of data you are
getting into your datatable (do youi need all columns, do you need all rows
?)...

--
Patrice

"mark-seattle" <markseattle@discussions.microsoft.com> a écrit dans le
message de groupe de discussion :
4C5B9005-AEA4-4EA0-BDC9-F95DD1000DB6@microsoft.com...
> Is there any performance difference between creating and filling a
> DataTable
> and a single datatable dataset, or is it really the same thing under the
> covers.
>
> In other words, do you pay any overhead for
>
>
> myDS = Create & Fill Dataset with single datatable
> MyDT = myDS.Tables(0)
>
> versus just creating DT directly as a datatable and filling it?
>
>
>

Re: DataTable versus DataSet by Cor

Cor
Wed May 07 23:11:53 CDT 2008

Yes,

But it is possible that you loose a lot of functionality which will cost you
more

Be aware that every datatable has a reference property to a dataset

Cor

"mark-seattle" <markseattle@discussions.microsoft.com> schreef in bericht
news:4C5B9005-AEA4-4EA0-BDC9-F95DD1000DB6@microsoft.com...
> Is there any performance difference between creating and filling a
> DataTable
> and a single datatable dataset, or is it really the same thing under the
> covers.
>
> In other words, do you pay any overhead for
>
>
> myDS = Create & Fill Dataset with single datatable
> MyDT = myDS.Tables(0)
>
> versus just creating DT directly as a datatable and filling it?
>
>
>