multiple local connections or single connection in database class?

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  - 1
    - RowChanged - Event Hi, Whenever adding or modify row to the datatable, RowChanged event getting fired. But it is not getting fired when deleting the row from the table. Is there any event fires when deletion of row happens ? Regards Indra Kumar Tag: multiple local connections or single connection in database class? Tag: 105376
  - 2
    - Data Abstraction Layer Hi I'm just about to start designing a quite large system using ADO.NET and Sql Server. I want to provide an object oriented abstraction of the underlying database structure. I've written my own custom data abstraction framework in the past and although it worked a treat, was very time consuming. Can anyone recommend any third party frameworks that they have used? I'm considering using the Type DataSets VS.NET provides and also ComponentOne's DataObjects. Any others? Many thanks Ben Tag: multiple local connections or single connection in database class? Tag: 105373
  - 3
    - Creating a dataset Hi all Can anyone point me to an article or something similar which will show me how to do the following 1) Webservice creates some object instances 2) Webservice creates some XML which looks like DataSet data 3) Client can then take the data and edit within a DataSet The objects on the server cannot have a parameterless constructor, so I can't make them [Serializable] (there are other reasons too). So I'd like to have the client work with datasets instead. Thanks -- Pete ==== Read or write articles on just about anything http://www.HowToDoThings.com My blog http://blogs.slcdug.org/petermorris/ Tag: multiple local connections or single connection in database class? Tag: 105372
  - 4
    - Distributed Data into Common Dataset Problem: I have two databases db1, db2 db1 contains a table with a keyfield ID (ms Access -- oleDbconnection1) db2 contains a table with a keyfield ID (SQL server -- SqlConnection1) I have generated two datasets from these tables DS1 and DS2 What I need is a Dataset (DS3) implementing the following logic Select all the ID's from DS1 that have no matching ID's in DS2 then put them in DS3 If I had the two tables in the same database I would have the following query: SELECT DS1.ID FROM DS1 LEFT JOIN DS2 ON DS1.ID = DS2.ID WHERE (((DS2.ID) Is Null)); Question, How do I do this in ADO.Net when the tables are not in the same database (require different connection objects) Thanks in advance Ed Warren Tag: multiple local connections or single connection in database class? Tag: 105370
  - 5
    - Concurrency Violation I have a DataTable which I did use as the source for a DataGrid, teh data table was popeulated form my database and when I made changes in the grid I used the same DataAdapter to chnage the values in the database. However, I now have the need (on a column by column basis) to show the values in the grid as a multiple of what is in the underlying datatable. Then if the user edits the grid I must then devide by the same value before updating the database again. My first effort for this was to have a DataTable representing the data in the database and another DataTable representing the data in the DataGrid. The before displaying any data in the grid or updating the database I would execute a function that copies (using ImportRow) each row from the display DataTable to the storage DataTable converting values as necessary as we go along. This seemed OK and each row kept the expected RowState. However, after I copy from the display DataTable to the storage DataTable and use the DataAdapter.Update method on the storage DataTable to put the changes back into the database I get the following error: concurrency violation: the updatecommand affected 0 records so it looks like I cannot accomplish what I am trying to do with two DataTables.. or can I? Or is there an easier way to do this? I know it looks stramge but I do have a valid requirement to do this. TIA Tag: multiple local connections or single connection in database class? Tag: 105368
  - 6
    - Reading Text datatype into a byte Array Hi, I am populating a records fetched from a select query in OleDbDataReader. The datbase is MS Access, The datatype of the select query column is Text. I want to read the data as Byte array instead of string as Reading it into a string causes it to be converted to Unicode which is do not want. Anybody is aware of some sites from where i can get valuable information or some sample project please do let me know about it. Any information provided will be greatly appreciated. Thanks in advance, Debu Tag: multiple local connections or single connection in database class? Tag: 105367
  - 7
    - Plz,I need your help Hi all of you I am student , and our supervisor ask us to make a short course registration system, but i couldn't do the following (The user is allowed to attempt to log-in to course database a maximum of 3 times in a session. If they fail to log in after 3 attempts, they are prevented from logging into the session from this or any other terminal. If the user-id is not recognized at all, the terminal is frozen for 5 minutes. If the user-id is recognized but the password isn't, the student record is 'locked' for the full session. In either type of log-in failure, the attempt is logged on a fault logging database. If the log-in is successful the student is added to the session's attendance list. If the login is successful, the student's attendance record for the whole course is updated). plz, i need your help because i am vb.net beginner Posted Via Usenet.com Premium Usenet Newsgroup Services ---------------------------------------------------------- ** SPEED ** RETENTION ** COMPLETION ** ANONYMITY ** ---------------------------------------------------------- http://www.usenet.com Tag: multiple local connections or single connection in database class? Tag: 105363
  - 8
    - Smart Card - ASP.NET Hello, I'm creating ASP.NET site that a client can login using smart cards as their password. And i have no idea how to beat it. Any help will be great. RK Tag: multiple local connections or single connection in database class? Tag: 105362
  - 9
    - SQLconnection? I want to connect sql database via ado.net but error is encounter as shown as below: Compilation Error ================= Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately. Compiler Error Message: BC30188: Declaration expected. Source Error: ============= Line 7: Dim myCommand As SqlCommand = New SqlCommand("select * from gldate", myConnection) Line 8: Line 9: myConnection.Open() Line 10: Line 11: Show Detailed Compiler Output: ============================== myConnection.Open() ~~~~~~~~~~~~ D:\SQLDB\Intranet\WebApp\Finance\subsystem\gl\dropdownlist.aspx(15) : error BC30188: Declaration expected. myConnection.Close() ~~~~~~~~~~~~ find.aspx ========= <%@ Page Language="VB" %> <%@ Import Namespace="System.Data" %> <%@ Import Namespace="System.Data.SqlClient" %> <script runat="server"> Dim myConnection As SqlConnection = New SqlConnection("server=(sql01);database=ERP_ARCHIVAL;user id=intranet;password=intranet") Dim myCommand As SqlCommand = New SqlCommand("select * from gldate", myConnection) myConnection.Open() Dim dr As SqlDataReader = myCommand.ExecuteReader() myConnection.Close() </script> <html> <head> <title>Intranet Information System</title> </head> <body> <form runat="server"> <asp:DropDownList id="DropDownList1" runat="server"></asp:DropDownList> </form> </body> </html> Please help. Tag: multiple local connections or single connection in database class? Tag: 105357
  - 10
    - converting string to uniqueidentifier hi, i am trying to insert data into sql server db using ado.net (vb.net) thru an insert statement. I have a uniqueidentifier field in the table and asp.net converts it to guid field and when i put guid.toString value in insert statement sql server exception occurs sayings cant convert string to uniqueidentifier Tag: multiple local connections or single connection in database class? Tag: 105345
  - 11
    - Passing Table to SP I have a table of about 20-200 rows that I would like to pass to a stored procedure as a parameter. Don't need any results back. the table will be in a known format to the sproc. This is not really an insert or update function as the sproc will process these values, but the data does not get stored as is in SQL. The sproc may perform a series of other updates as a result of these parameter / values. Basically a table as a parameter. Kind of the opposite of what I normally do with a table or dataset. Maybe I am making more of this that need be or missing something obvious? Sorry for the vague question. -Andrew Tag: multiple local connections or single connection in database class? Tag: 105343
  - 12
    - MS Access Update Query I am running WinXP with and ASP.Net application. When I invoke a stored Access query which is going to update a table, I get and error message of "Operation must use an updateable query". Microsoft has a KB article on the subject and it indicates that the problem is a security issue and that I need to grant read/write authority to "IUSER". I went to the folder which contained my folder within the wwwroot directory. Using Windows Explorer I clicked on the IUSER Account and granted it "Full access" to the folder which contains my file as well as the file itself, but this has had no effect. So I am not doing something correct. Is the "IUser" not the correct account for ASP.Net for XP or have I done something incorrect in granting authority to IUser? When I look at the file permissions of the directory, I see the "Deny" greyed out but checked for "Special Permissions" and "Write". the "Special Permissions" is not checked for "Allow" and it is checked for "Special Permissions". Is this the way it is suppose to be? Thanks in advance for your assistance!!! Tag: multiple local connections or single connection in database class? Tag: 105341
  - 13
    - Codegen not working My header is as follows: <xs:schema id="dsClientT" targetNamespace="http://www.tempuri.org/dsClientT.xsd" xmlns:codegen="urn:schemas-microsoft-com:xml-msprop" xmlns:mstns="http://www.tempuri.org/dsClientT.xsd" xmlns="http://www.tempuri.org/dsClientT.xsd" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata" attributeFormDefault="qualified" elementFormDefault="qualified"> My element line is: <xs:element name="WorkCDN" codegen:nullValue="0" type="xs:boolean" /> However, when I call Addnew() if I have databinding on checkbox it still doesn't work, it seems the datarow that is returned is still returning dbnull and and not flase for this boolean variable. Any inputs ? HS Tag: multiple local connections or single connection in database class? Tag: 105340
  - 14
    - Connection String Hello Does anyone have an example to store the connection string to a file, which can be edited so that the application can run on clients environement. hardcoding the connection string doesn't seem to be a good idea. Thanks HS Tag: multiple local connections or single connection in database class? Tag: 105337
  - 15
    - Building SQL Commands in .NET with DateTime that run against SQL Servers with different regional settings Hi, I'm bulding SQL Commands with System.Threading.Thread.CurrentThread.CurrentCulture = cu String.Format(MSSQLComand, Startdate.ToShortDateString, EndDate.ToShortDateString) When I'm running this against an English Database Server this works, how ever this does not againt an Italian one. What is best practice to fight this localization issue? Thanks in advance for any advice Andrew -- Andrew Smith Tag: multiple local connections or single connection in database class? Tag: 105333
  - 16
    - one sql connection for multiple web forms Hello, I am learning ADO.NET, so please bear with me. Currently, I am coding in VB.NET and running a SQL Server 2000. My question is this, how do I use only one SQLConnection for multiple web forms? Is this even possible? Thanks in advance, -new2.NET Tag: multiple local connections or single connection in database class? Tag: 105320
  - 17
    - Need to return Data Across DataSet Tables... ... not sure what the best way to do this. What i need to do is return all the records in 1 table that don't exist in another table. scenio Table A contains a list of Tasks to work on. Table B contains a list of Tasks that are currently being worked on. So what I need returned is a list of all Tasks not being worked on. SELECT * FROM A WHERE (NOT (A_ID IN (SELECT A_ID FROM B))) I don't believe I can do a select across tables in a dataset. Ideas? Tag: multiple local connections or single connection in database class? Tag: 105319
  - 18
    - Sorting and Filtering dates in a Dataview I'm trying to filter a range of dates in a dataview. Problem is single digit days and months are getting mixed in with double digit days and months. eg) rowfilter='DT>03/25/2005 AND <03/27/2005' returns anything with a date of 03/2/2005 along with what it should return. any fixes? Tag: multiple local connections or single connection in database class? Tag: 105316
  - 19
    - Bind these ComboBoxes - Can it be done? I have 3 tables as follows: Table 1 - item list Table 2 - master table Table 3 - where selected values are stored and detail table to master. I want to Bind 8 ComboBoxes using these tables in pairs so there will be 4 pairs. Detail table def: masteridx pos value1 value2 Each ComboBox gets its list from Table1. When selected, the value goes to Table3. value1 and value2 from Table3 are a pair of values which go to the same record in Table3. masteridx in Table3 is the index or record id from Table2. Pos from Table3 is the pair of ComboBoxes to use. I hope I made this clear enough. It's really confusing. Thanks, Joe Tag: multiple local connections or single connection in database class? Tag: 105315
  - 20
    - Error when I using extended stored procedure : A severe error occurred on the current command. The results, if any, should be discarded Hi, I create a stored procedure to send email with an OLE instance (sp_send_mail). "EXEC @hr = sp_OACreate 'CDO.Message', @iMsg OUT ...etc." I have rigth to execute extended stored procedure sp_OACreate (and others in database master) After, in my DOTNET application, i execute my procedure with ExecuteNonQuery and i have a sql error : "A severe error occurred on the current command. The results, if any, should be discarded." Can you help me ? Thanks Tag: multiple local connections or single connection in database class? Tag: 105313
  - 21
    - Typed dataset and save? Hi, When using a typed dataset is it possible to do the following: 1 - force date values to get saved as just the date part... "2005-01-28" not "2005-01-28T00:00:00.0000000-00:00" type is defined as type="xs:date" in the schema. 2 - specify a style sheet so that it gets written to the xml that is generated by the DataSet.WriteXml method. Thanks Donal Tag: multiple local connections or single connection in database class? Tag: 105310
  - 22
    - Sort Order - Can it be preserved in this situation. Question. Is there a way I can get the order preserved (possibly with a SQL config option or such) using the folowing; Select ..... into #temptable where ... Order By ... then Select * from #temptable and have the order preserved in accordance with the select statements Order By clause used to build the temptable. .. using ADO.NET 1.1 with the MS_SQL Client - ExecuteReader() method. I am porting an application that used SQL 6.5 in this manor and it seememd to preserve the order using this pattern, however, Sql2000 does not. Thanks. Tag: multiple local connections or single connection in database class? Tag: 105309
  - 23
    - XML serialization exception with .NET 1.0 and 1.1 environment Sorry for the repost but I ddn't use my MSDN "handle" when I posted earlier.... Hi all I get an exception when trying to deserialize a simple configuration file using XML Serialization. The stacktrace can be seen at the bottom of this message. I've see other messages related a similar error but none of the solutions suggested are valid in case :/ I have tracked the problem down to the compilation of the temporary DLL that handles the actual serialization. The following commandline (all on a single line) is executed by the framework when trying to deserialize my configuration: "c:\windows\microsoft.net\framework\v1.1.4322\csc.exe" /t:library /utf8output /R:"c:\windows\assembly\gac\system.xml\1.0.5000.0__b77a5c561934e089\system.xml.dll" /R:"c:\program files\MyApp\MyConfig.dll" /R:"c:\windows\microsoft.net\framework\v1.1.4322\mscorlib.dll" /out:"C:\DOCUME~1\User\LOCALS~1\Temp\i2_6axn4.dll" /debug- /optimize+ /w:1 "C:\DOCUME~1\User\LOCALS~1\Temp\i2_6axn4.0.cs" Note that it uses the .NET 1.1 compiler and core lib but references the .NET 1.0 XML assembly. The result is that the assembly isn't created and hence cannot be loaded. I've specifeid the required runtime version in the .config file to be .NET 1.1 without any improvements. The problems occur on a Windows XP test machine with both .NET 1.0 and 1.1. The application is built using VS.NET 2003 on a machine with only .NET 1.1. The user running the code on the test machine has administrative rights. I've have tried the XmlSerialization precompiler and it works without problems... Anyone have any ideas why this happens? Kind regards, HakonB Exception: System.Configuration.ConfigurationException: Unable to load configuration from the XML configuration file: 'C:\Program Files\MyApp\MyApp.exe.config'. This can be caused by a number of problems, but the most common problem is an incorrectly configured Updater configuration file. The most probable sources of error are: missing nodes, incorrect attribute names, white space within attributes or within elements, white space between elements in the same sub-node, badly formed xml, or xml that does not conform to the ConfigSchema.XSD. ---> System.Configuration.ConfigurationException: Exception in configuration section handler (C:\Program Files\MyApp\MyApp.exe.config line 16) ---> System.IO.FileNotFoundException: File or assembly name _zdvwu31.dll, or one of its dependencies, was not found. File name: "_zdvwu31.dll" at System.Reflection.Assembly.nLoad(AssemblyName fileName, String codeBase, Boolean isStringized, Evidence assemblySecurity, Boolean throwOnFileNotFound, Assembly locationHint, StackCrawlMark& stackMark) at System.Reflection.Assembly.InternalLoad(AssemblyName assemblyRef, Boolean stringized, Evidence assemblySecurity, StackCrawlMark& stackMark) at System.Reflection.Assembly.Load(AssemblyName assemblyRef, Evidence assemblySecurity) at System.CodeDom.Compiler.CompilerResults.get_CompiledAssembly() at System.CodeDom.Compiler.CompilerResults.get_CompiledAssembly() at System.Xml.Serialization.Compiler.Compile() at System.Xml.Serialization.TempAssembly..ctor(XmlMapping[] xmlMappings) at System.Xml.Serialization.XmlSerializer..ctor(Type type, String defaultNamespace) at System.Xml.Serialization.XmlSerializer..ctor(Type type) at DSUpdater.UpdaterSectionHandler.System.Configuration.IConfigurationSectionHandler.Create(Object parent, Object configContext, XmlNode section) in C:\Projects\MyApp\MyApp\ConfigSectionHandler.cs:line 55 at System.Configuration.ConfigurationRecord.EvaluateRecursive(IConfigurationSectionHandler factory, Object config, String[] keys, Int32 iKey, XmlTextReader reader) === Pre-bind state information === LOG: Where-ref bind. Location = C:\DOCUME~1\User\LOCALS~1\Temp\_zdvwu31.dll LOG: Appbase = C:\Program Files\MyApp\ LOG: Initial PrivatePath = NULL Calling assembly : (Unknown). === LOG: Policy not being applied to reference at this time (private, custom, partial, or location-based assembly bind). LOG: Attempting download of new URL file:///C:/DOCUME~1/User/LOCALS~1/Temp/_zdvwu31.dll. --- End of inner exception stack trace --- at System.Configuration.ConfigurationRecord.EvaluateRecursive(IConfigurationSectionHandler factory, Object config, String[] keys, Int32 iKey, XmlTextReader reader) at System.Configuration.ConfigurationRecord.Evaluate(String configKey) at System.Configuration.ConfigurationRecord.ResolveConfig(String configKey) at System.Configuration.ConfigurationRecord.GetConfig(String configKey) at System.Configuration.DefaultConfigurationSystem.System.Configuration.IConfigurationSystem.GetConfig(String configKey) at System.Configuration.ConfigurationSettings.GetConfig(String sectionName) at DSUpdater.UpdaterConfiguration.Init() in C:\Projects\MyApp\MyApp\UpdaterConfiguration.cs:line 133 --- End of inner exception stack trace --- at DSUpdater.ApplicationUpdateManager..ctor() in C:\Projects\MyApp\DSUpdater\ApplicationUpdater.cs:line 98 at MyApp.Client.Services.SmartUpdateService.Initialize(Form form) in C:\Projects\MyApp\MyApp\Services\SmartUpdateService.cs:line 32 at MyApp.Client.MainForm.Handler_CheckForUpdates(Object sender, EventArgs e) in C:\Projects\MyApp\MyApp\MainForm.cs:line 570 at MyApp.Common.ActionHandler.ExecuteHandler(Object sender, EventArgs args) in C:\Projects\MyApp\MyCommon\General\ActionDispatcher.cs:line 252 at MyApp.Common.General.ActionDispatcher.Fire(String handlerName, Object sender, EventArgs args) in C:\Projects\MyApp\MyCommon\General\ActionDispatcher.cs:line 195 at MyApp.Client.MainForm.MainForm_Load(Object sender, EventArgs e) in C:\Projects\MyApp\MyApp\MainForm.cs:line 423 at System.Windows.Forms.Form.OnLoad(EventArgs e) at System.Windows.Forms.Form.OnCreateControl() at System.Windows.Forms.Control.CreateControl(Boolean fIgnoreVisible) at System.Windows.Forms.Control.CreateControl() at System.Windows.Forms.Control.WmShowWindow(Message& m) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ScrollableControl.WndProc(Message& m) at System.Windows.Forms.ContainerControl.WndProc(Message& m) at System.Windows.Forms.Form.WmShowWindow(Message& m) at System.Windows.Forms.Form.WndProc(Message& m) at System.Windows.Forms.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam) Tag: multiple local connections or single connection in database class? Tag: 105306
  - 24
    - DataView sort I have an xml from two different database source that I load into the dataset. one of the column is a date field and I want to sort the date. Its sorting the date as string as the datatype for the column is string. Can I change the datatype of the column ? since I cannot sort it on the database side can I do it in the dataview ? Please help... Thanks, Tag: multiple local connections or single connection in database class? Tag: 105304
  - 25
    - Why question not answered? I don't understand why the question below has not been answered here. I assume I am in the right newgroup. To me it seems a reasonable question. What gives? If reviewing how to get the DataRowVersion data from a row in a dataset I see no example of how to do this with a strongly typed dataset using dot notation. Below I have an example of how I get a value into a integer value called OrigStatus not using dot notation. OrigStatus = CInt(Me.DataSetQuoteDetail1.quote(0)("quote_status_id", DataRowVersion.Original)) As you see, in the example above it is necessary for me to supply the name of the column in quotation marks. Is there a way to do this in a strongly typed dataset using dot notation so that I don't have to supply the column name in quotation marks? Tag: multiple local connections or single connection in database class? Tag: 105297
- Next
  - 1
    - DataBinding to a combo box. Hi I have two tables... DataSources(id, Type, Name) DataSourcesTypes(id, TypeDescription) DataSourcesTypes contains lookup field data that will populate the Type field in the DataSource table. I would like to setup a comboBox with the following... DisplayMember = DataSourcesTypes.TypeDescription ValueMember = DataSources.Type The ultimate effect being a form that displays the description in a combo box but is altering the ID field in the dataSource table for the particular dataSource being edited. I understand that a relationship should be setup but I cannot get it to work ? thanks for any time on this Sharat Koya Tag: multiple local connections or single connection in database class? Tag: 105293
  - 2
    - Problem with sqlDataAdapter.fill performance Hi I am a newbie to the ADO .NET. I use a dataset as datasource for a web Crystal Report. I fill this dataset using a sqlDataAdapter. The selectCommand is quite complex and use many table and relations. The execution of the fill command is very long (it takes about 30 sec.), but if i run the select command in the query builder it takes about 2 sec, so i think that the problem is not the execution of the query by SQLServer. How can i speeed up the fill of this dataset ? Thank you - Daniele - Tag: multiple local connections or single connection in database class? Tag: 105286
  - 3
    - How to Get Year/Month/Date of a DateTime Column by Column.Expressi I mean to create a new column with Integer type, which is defined by its expression to be Year/Month/Date of a DateTime Column. Of course, It is simple to define such a new column by Substring(Convert(DateTimeColumn,"System.String"),x,y) to get Year/Month/Date of DateTime Column if we know the DataTable.Local when we code the expression. If not, how to do? Any suggestions are welcome. LI Ying Tag: multiple local connections or single connection in database class? Tag: 105285
  - 4
    - Event on record change I have some controls on my form which are bound to a dataset and some which are not bound. But whatever record is displayed on the form, I want to populate those control (datetime, combo, etc.) with the data in the current record. What event can I do this in ? PositionChanged of bindingContext - is this called before the record is current or after ? if it is after, I can use this. Please advise. HS Tag: multiple local connections or single connection in database class? Tag: 105267
  - 5
    - Connect to Exchange Server 2000 Hi all, Can anyone direct me to where I can find sample code on how to connect to an Exchange Server with .NET? The Exchange OLEDB Provider doesn't seem to work with ADO .NET? /kk Tag: multiple local connections or single connection in database class? Tag: 105259
  - 6
    - Database update help needed I am a newbie to the ADO .NET stuff. I am using Visual Studio 2003/ VB to develop an app. Been doing development for a long time, but having a tough time getting my hands around the new way of doing things. Hoping you can help. First, is there a site or book you can point me to that will describe this stuff in detail? I can't seem to get the stuff I am reading/trying to work. Second, can someone give me a basic idea on the "preferred" use of data adapters and datasets? Separate DS for each DA, or one DS for all DAs? Lastly, I have an issue of data not being saved. I have a DB connection to an Access DB, a DA with the necessary SQL statements for update and insert, and a group of text controls bound to the data. I open the form and the data is there. I make changes and then issue: MyDataAdapter.Update(MyDataSet) I get no errors, but nothing changes in the DB. Part of the issues for me are understanding the opening/closing of the connection and how the data in the DS gets back to the actual DB. Sorry for the long question/post and many questions. I appreciate any help!! Tag: multiple local connections or single connection in database class? Tag: 105258
  - 7
    - Addnew() I have a checkbox, date time picker & few comboboxes bound to the same dataset I know checkbox, datetimepicker won't let me have null when I call AddNew() Also because if I bind my combo boxes to the same dataset they all change automagically. So my theory: On Addnew(), before addnew is called, unbind the checkbox & datetimepicker & comboboxes and before endcommit is called, populate the new record with the value in these controls. sounds good eh ? Now can someone help me put that into code? Thanks :) HS Tag: multiple local connections or single connection in database class? Tag: 105257
  - 8
    - Having problem with typed dataset with multiple tables. I have a typed DataSet that contains 4 tables. I have mapped a data adapter to all of the tables in the DataSet. The select command for the data adapter has a multiple join on all four tables in the typed DataSet. When I try to do the Fill command, I get an InvalidOperationExcpetion. The message says that there is an invalid source mapping for one of my columns. If I change my select statement to only return rows from one table in the result set, it works fine. Not sure why the other table mappings are not working. My select string looks something like this: select top 500 * from tblEventImages left outer join tblEventOccurrences on tblEventImages.EventID = tblEventOccurrences.EventID left outer join tblImageAnnotations on tblEventImages.TimeDate = tblImageAnnotations.TimeDate left outer join tblEventTransactions on tblEventImages.EventID = tblEventTransactions.EventID Could someone please indicate how to do the data adapter table mapping for this? Maybe I am doing something wrong here, but I cannot figure out what it is. -- ----------------------------------- Ken Varn Senior Software Engineer Diebold Inc. EmailID = varnk Domain = Diebold.com ----------------------------------- Tag: multiple local connections or single connection in database class? Tag: 105254
  - 9
    - What happens when I change the RowUpdatedEventArgs? What I want to do is catch and dismiss expected errors during an update (resolve the problem and allow the update to continue) but have unexpected errors throw their exception normally (stopping the update). To accomplish this, I created a method and attached it to the SqlDataAdapter.RowUpdated event. It looks similar to this, private void errorHandler(object sender, SqlRowUpdatedEventArgs args) { if(args.Status != UpdateStatus.ErrorsOccurred) { return; } // determine if the error should be ignored if(ignoreError) { // error should be ignored args.Status = UpdateStatus.Continue; args.Errors = null; } } With this code in place, errors I've ignored still throw an exception and halt the update. This behavior leads me to the conclusion that changing properties on the SqlRowUpdatedEventArgs object in my method have no lasting effect. Should this be so? Can someone please tell me if I have a logical or conceptual flaw here? Thanks! Matt P.S. This is running on the CompactFramework Tag: multiple local connections or single connection in database class? Tag: 105253
  - 10
    - Error when using System.Data.Relations.Add Using an informix database, I'm retrieving two datasets and copying the data table from one dataset into the other, so I've got 1 dataset with 2 tables. This is just background because it might be part of the problem. After this, I simply want to create a data relation between the two tables, so I call the constructor for a new datarelation, which appears to work fine. I get an error when I'm trying to use the Add method of the dataset. The error is: "System.ArgumentException: This constraint cannot be enabled as not all values have corresponding parent values." Any ideas? Below is the code I'm using. Thanks! Diane Droubay ----------------------------- //copy the budget detail from the detail dataset, then add to the budget dataset DataTable dt = dsDetail.Tables[0].Copy(); dsBudget.Tables.Add(dt); dsBudget.Tables[0].TableName = "Budget"; dsBudget.Tables[1].TableName = "Detail"; DataColumn dcBudgetId; DataColumn dcBudgetDetailId; //budget_id is primary key in Budget table and foreign key in Detail table. dcBudgetId = dsBudget.Tables["Budget"].Columns["budget_id"]; dcBudgetDetailId = dsBudget.Tables["Detail"].Columns["budget_id"]; DataRelation rel = new DataRelation("Budget2Detail", dcBudgetId, dcBudgetDetailId); //crashes on the next call. dsBudget.Relations.Add(rel); Tag: multiple local connections or single connection in database class? Tag: 105248
  - 11
    - Datalist not displaying records from stored procedure Hi, I have created and tested a stored procedure with some input values and one output value. When I run it the page seems to come up but no data exists, and no errors. This is odd because there if definitely info ont he table/datbase. My code is below if anyone can see what I might be doing wrong. Dim MyConnection As New SqlConnection(ConfigurationSettings.AppSettings ("ConnectionString")) Dim cmd As New SqlCommand("uspSearch", MyConnection) cmd.CommandType = CommandType.StoredProcedure cmd.Parameters.Add("@suburbtown", SqlDbType.Varchar, 30) cmd.Parameters("@suburbtown").Direction = ParameterDirection.Input cmd.Parameters("@suburbtown").Value = "" cmd.Parameters.Add("@accountant_type", SqlDbType.Int) cmd.Parameters("@accountant_type").Direction = ParameterDirection.Input cmd.Parameters("@accountant_type").Value = 15 cmd.Parameters.Add("@keyword", SqlDbType.Varchar, 25) cmd.Parameters("@keyword").Direction = ParameterDirection.Input cmd.Parameters("@keyword").Value = "" cmd.Parameters.Add("@state", SqlDbType.Varchar, 3) cmd.Parameters("@state").Direction = ParameterDirection.Input cmd.Parameters("@state").Value = "TAS" cmd.Parameters.Add("@PageSize", SqlDbType.Int) cmd.Parameters("@PageSize").Direction = ParameterDirection.Input cmd.Parameters("@PageSize").Value = 10 cmd.Parameters.Add("@CurrentPage", SqlDbType.Int) cmd.Parameters("@CurrentPage").Direction = ParameterDirection.Input cmd.Parameters("@CurrentPage").Value = 1 cmd.Parameters.Add("@FullCount", SqlDbType.Int) cmd.Parameters("@FullCount").Direction = ParameterDirection.Output Dim adapter As New SqlDataAdapter(cmd) Dim ds As New DataSet() adapter.Fill(ds) ListResults.DataSource = ds ListResults.DataBind() -- Message posted via http://www.dotnetmonster.com Tag: multiple local connections or single connection in database class? Tag: 105240
  - 12
    - DataReader question Is the following code a valid way of passing a DataReader object back to calling code? I'm specifically concerned with the objConn object be explicitly set to Nothing. Does this cause the connection object to be garbage collected or does the connection object not get destroyed until the calling code closes the DataReader object (and thus the connection object)? Public Function GetDataReader(ByVal strSelect As String) As OleDbDataReader Try objConn = New OleDbConnection(strConnectionString) objCmd = New OleDbCommand(strSelect, objConn) objCmd.Connection.Open() GetDataReader = objCmd.ExecuteReader(CommandBehavior.CloseConnection) Catch ex As OleDbException GetDataReader = Nothing Finally objConn = Nothing objCmd = Nothing End Try End Function Tag: multiple local connections or single connection in database class? Tag: 105238
  - 13
    - Record Locking I was going to start a project in VB.net using ADO.net to a FoxPro database. Foxpro has a RLOCK function that allows you to lock a record while you are editing it. How can I achieve this with ADO.net?? Tag: multiple local connections or single connection in database class? Tag: 105237
  - 14
    - Can I use Query Builder from my application? Hi, Is there any way to use in my application Query Builder that Microsoft is using in SQL Server and DataAdapter Wizard where I can drag and drop tables, link them in graphical designer and run resulting sql statement? Is it possible or is it just part of SQL Server and VS? Thank you. Victor Tag: multiple local connections or single connection in database class? Tag: 105234
  - 15
    - How to manager empty string to null? How do I manage empty string to null? Do I have to code like following? if(txtBoxFirstName.text == "") cmd.Parameters.Add("@FirstName",DBNull.Value): else cmd.Parameters.Add("@FirstName",txtBoxFirstName.text): Or are there better ways? Also, I am curious about how to manage for integer as well. Tag: multiple local connections or single connection in database class? Tag: 105225
  - 16
    - what can cause a "object was open" error Hi, I am writing an ASP.NET appliction with C#. I also access a MSDE database with the OleDb Provider. I am using OleDb to have the option of easily changing the underlying database. That worked all well. But after some additions to my application I now have the following error: Exception: System.Data.OleDb.OleDbException Message: Object was open. at System.Data.OleDb.OleDbConnection.ProcessResults(Int32 hr) at System.Data.OleDb.OleDbConnection.InitializeProvider() at System.Data.OleDb.OleDbConnection.Open() This error does occur in some code snippets all the time, in some other it seems that it only happens sometimes. I tried to find out more about the error by investigating the problem in a code snippet where it always occurs. But it doesn't help. It is just an INSERT statement to one table. I already tried synchronizing the code snippet and commenting out all other accesses to the same table to avoid any collisions by multiple threads that try to access it, but it still doesn't work. The connection itself is closed, so "Object" must mean something else. But what? Any ideas? Regards Marco Tag: multiple local connections or single connection in database class? Tag: 105224
  - 17
    - DataRowVersion - Strongly typed dataset If reviewing how to get the DataRowVersion data from a row in a dataset I see no example of how to do this with a strongly typed dataset using dot notation. Below I have an example of how I get a value into a integer value called OrigStatus not using dot notation. OrigStatus = CInt(Me.DataSetQuoteDetail1.quote(0)("quote_status_id", DataRowVersion.Original)) As you see, in the example above it is necessary for me to supply the name of the column in quotation marks. Is there a way to do this in a strongly typed dataset using dot notation so that I don't have to supply the column name in quotation marks? Tag: multiple local connections or single connection in database class? Tag: 105223
  - 18
    - Binding to a bound grid Hi, This question is in relation to a System.Web.UI.DataGrid If I bind some data to a grid, then in a subsequent postback bind to it again, does the grid intrincially clear its contents before adding the new information. TIA Tag: multiple local connections or single connection in database class? Tag: 105222
  - 19
    - DataAdapter newbie question I have two questions regarding the use of DataAdapters: 1. If I am going to retrieve multiple tales to a DataSet using multiple DataAdapter Fill's is it best to create a separate DataAdapter for each table or to create one and change it's SelectCommand property between each Fill? 2. Related to number 1, is it best to explicitly open the connection before the series of Fill's and close after rather than allow each DataAdapter to implicitly open and close the connection. TIA, John Tag: multiple local connections or single connection in database class? Tag: 105221
  - 20
    - Comparing Dataset values with Strings I am creating a login screen wherein only certain users are granted permission. The names of those users,are copied into a dataset using dataadapter.Then the dataview is used. But the problem here is that the "Dv.Count" always evaluates ..to 0. Hence whenever I enter the valid names "Invalid User" is prompted on the screen I have writen the code below. OleDbDataAdapter dAdap1 = new OleDbDataAdapter("SELECT ..[EMPLOYEE ID] FROM EMPLOYEE;",con1); dAdap1.Fill(DtSet); Dv.Table=DtSet.Tables["EMPLOYEE"]; Dv.RowFilter.CompareTo(txtLogin.Text); if(Dv.Count==0) { txtLogin.Text="Invalid User"; } Kindly suggest, Tag: multiple local connections or single connection in database class? Tag: 105217
  - 21
    - Binding Data with TextBox I want add a new record using a text box, but when I click the new button it should clear the text of textbox and textbox should be binded to datasource. pls help! Tag: multiple local connections or single connection in database class? Tag: 105216
  - 22
    - Insert data from a Dataset into a SQL Database Hi guys my name is Ralph, i am kinda new to this so please bear with me. I have written a .net web service which accepts a stream of data see relevent source code). Public Function PutBondInfo(ByVal data As String) As DataSet Try Dim zh As New ZipHelper Dim sz As String Dim cn As SqlConnection Dim da As SqlDataAdapter Dim ds As New DataSet Dim xSet As New DataSet Dim sSql As String Dim mySerializer As XmlSerializer = New XmlSerializer(ds.GetType()) cn = New SqlConnection("server=HLSQL;uid=test;pwd=;database=test") cn.Open() da = New SqlDataAdapter("SELECT * FROM BondStatus", cn) 'da.TableMappings.Add("BondStatus", "NewDataSet") sz = zh.Decompress(data) zh = Nothing da.FillSchema(ds, SchemaType.Mapped, "BondStatus") 'da.MissingSchemaAction = MissingSchemaAction.AddWithKey da.Fill(ds, "BondStatus") Dim st As New MemoryStream(Encoding.UTF8.GetBytes(sz)) ' Create the object from the xml file xSet = CType(mySerializer.Deserialize(st), DataSet) xSet.Tables(0).TableName = ds.Tables(0).TableName ds.Merge(xSet, False, System.Data.MissingSchemaAction.Add) 'ds.AcceptChanges() Dim SqlCB As SqlCommandBuilder = New SqlCommandBuilder(da) da.Update(ds, "BondStatus") st.Close() da.Dispose() SqlCB.Dispose() cn.Close() Return ds Catch ex As Exception ex.Message().ToString() End Try End Function This data is compressed.I decompress the data and receive the xml which is then deserialized into a dataset. this part works great no problems. My problem is then taking that dataset and pushing the data into a table on my SQL server. The elements in the xml and the field names of my SQL table 'BondStatus' are exactly the same. The table names are different the xml has 'Table' as its table name and so on. As you can see from the code I have tried table mappings, assigns, merges etc with no luck. Ladies and gents if anyone has a clue as to what I am doing and can help me, it would be appreciated. Thanks in advance Ralph Tag: multiple local connections or single connection in database class? Tag: 105211
  - 23
    - Stored Procedure Hi, I've 2 stored procedures in Sql Server 2000 by name QA_User_Insert and QA_Insert_Candidate. Am using Oledb connection to connect to Sql server 2000. and i wrote following code in ASP.Net Dim MyConn As OleDbConnection = New OleDbConnection("uid=sa;Intial Catelog=Quiz;data source=server;pwd=thanks;provider=SQLOLEDB.1") Dim cmd As New OleDbCommand cmd.Connection = MyConn cmd.CommandType = CommandType.StoredProcedure cmd.CommandText = "QA_User_Insert" \\ Here i created paramentes and added to parameters collection of cmd object. \\ cmd.ExecuteNonQuery() then after running the application am getting Error "Can Not Found Stored Procedure QA_User_Insert" I 've checked sql server 2000 and i found that there is QA_User_Insert stored Procedure. why am getting this error ? plz can anybody tell me solution for this problem. Thanx in advance Jyothi Tag: multiple local connections or single connection in database class? Tag: 105205
  - 24
    - sqlexception error in system.data.sqlclient.dll Hi everyone, i'm a newbie to VB.NET programming and i need help here. I'm current doing an application for pocket pc and i get this sqlexception error when i try to retrieve stuff from the database. My guess is that the error lies with the connection string. I've tried serveral different connection string but i still get the error. Try cn = New System.Data.SqlClient.SqlConnection("DATA SOURCE=L311C007; Initial Catalog=HEALTHCARE; Integrated Security=SSPI;") cn.Open() cmd.CommandText = "SELECT * FROM PERSON" cmd.Connection = cn Catch ex As System.Data.SqlClient.SqlException result = "There was an SqlException.." & vbCrLf & "Details..." & vbCrLf & ex.ToString() MsgBox(result) End Try The connection strings that i have tried are: User id=sa;password=;database=HEALTHCARE;server=L311C007 Data Source=L311C007,14433;Initial Catalog=HealthCare;User id=sa;password=; Tag: multiple local connections or single connection in database class? Tag: 105204
  - 25
    - AdoHelper Dependency Problem Hi I'm using the GotDotNet.ApplicationBlocks.Data.AdoHelper class in one of my projects, and it's working fine on my development machine. the problem however arises when deploying the project to another machine. I get a FileNotFoundException in the type initializer of AdoHelper. It claims it can't find a dependency, although inspection of the AdoHelper source code seems to show that it doesn't depend on anything other than the .Net Framework. The specific line of code which fails is this: Additionally the stack trace shows that the error occurs within a System.Reflection class. AdoHelper adoHelper = AdoHelper.CreateHelper("GotDotNet.ApplicationBlocks.Data","GotDotNet.ApplicationBlocks.Data.SqlServer"); Interestingly it seems to work fine if I create the SqlServer helper directly. Anyone got any thoughts? Cheers Andrew Tag: multiple local connections or single connection in database class? Tag: 105194

Is is better to:

(1) Have a single connection object in a database class which is
instantiated when first used at start-up and used by other classes (opened
and closed as necessary - NOT kept open).

or

(2) Local variable connections created in the function in which they are
used (and maybe reference the connectionstring in the database class)?

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Re: multiple local connections or single connection in database class? by Cor

Cor
Fri Feb 18 07:40:57 CST 2005

John,

There is in this in my opinon no better, just think how much you have to
type (correct by a change) for your solutions and than you know the answer.

Just my thought,

Cor

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Re: multiple local connections or single connection in database class? by Paul

Paul
Fri Feb 18 08:20:13 CST 2005

On Fri, 18 Feb 2005 08:33:59 -0500, "John B" <spamfree@hotmail.con> wrote:

¤ Is is better to:
¤
¤ (1) Have a single connection object in a database class which is
¤ instantiated when first used at start-up and used by other classes (opened
¤ and closed as necessary - NOT kept open).
¤
¤ or
¤
¤ (2) Local variable connections created in the function in which they are
¤ used (and maybe reference the connectionstring in the database class)?

Requirements can vary depending upon the type of application and database you are working with, but
the general recommendation is to open (and close) connection objects on an as needed basis rather
than attempt to maintain any type of single persistent and/or global connection.

Paul ~~~ pclement@ameritech.net
Microsoft MVP (Visual Basic)

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Re: multiple local connections or single connection in database class? by NuTcAsE

NuTcAsE
Fri Feb 18 09:39:29 CST 2005

The first option, which tough seems very easy and less code to wirte,
might start giving you problems on the multi threaded client, service
or an ASP.Net app being accessed by multiple user. If you use one
connection object that is being re-used by many functions, in a multi
threaded enviroment you could have synchronizing issues. Id suggest (2)
using a shared connection string.

NuTcAsE

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