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Search found 30 results on 2 pages for 'oledbdatareader'.

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  • c# display DB table structure

    - by user3529643
    I have a question. My code is the following : public partial class Form1 : Form { public OleDbConnection datCon; public string MyDataFile; public ArrayList tblArray; public ArrayList fldArray; public Form1() { InitializeComponent(); lvData.Clear(); lvData.View = View.Details; lvData.LabelEdit = false; lvData.FullRowSelect = true; lvData.GridLines = true; } private void DataConnection() { MyDataFile = Application.StartupPath + @"\studenti.mdb"; string MyCon = @"provider=microsoft.jet.oledb.4.0;data source=" + MyDataFile; try { datCon = new OleDbConnection(MyCon); } catch (Exception ex) { MessageBox.Show(ex.Message); } FillTreeView(); } private void GetTables(OleDbConnection cnn) { try { cnn.Open(); DataTable schTable = cnn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, new Object[] { null, null, null, "TABLE" }); tblArray = new ArrayList(); foreach (DataRow datrow in schTable.Rows) { tblArray.Add(datrow["TABLE_NAME"].ToString()); } cnn.Close(); } catch (Exception ex) { MessageBox.Show(ex.Message); } } private void GetFields(OleDbConnection cnn, string tabNode) { string tabName; try { tabName = tabNode; cnn.Open(); DataTable schTable = cnn.GetOleDbSchemaTable(OleDbSchemaGuid.Columns, new Object[] { null, null, tabName }); fldArray = new ArrayList(); foreach (DataRow datRow in schTable.Rows) { fldArray.Add(datRow["COLUMN_NAME"].ToString()); } cnn.Close(); } catch (Exception ex) { MessageBox.Show(ex.Message); } } private void FillTreeView() { tvData.Nodes.Clear(); tvData.Nodes.Add("Database"); tvData.Nodes[0].Tag = "RootDB"; GetTables(datCon); // add table node for (int i = 0; i < tblArray.Count; i++) { tvData.Nodes[0].Nodes.Add(tblArray[i].ToString()); tvData.Nodes[0].Nodes[i].Tag = "Tables"; } // add field node for (int i = 0; i < tblArray.Count; i++) { GetFields(datCon, tblArray[i].ToString()); for (int j = 0; j < fldArray.Count; j++) { tvData.Nodes[0].Nodes[i].Nodes.Add(fldArray[j].ToString()); tvData.Nodes[0].Nodes[i].Nodes[j].Tag = "Fields"; } } this.tvData.ContextMenuStrip = contextMenuStrip1; contextMenuStrip1.ItemClicked +=contextMenuStrip1_ItemClicked; } public void FillListView(OleDbConnection cnn, string tabName) { OleDbCommand cmdRead; OleDbDataReader datReader; string strField; lblTableName.Text = tabName; strField = "SELECT * FROM [" + tabName + "]"; // Initi cmdRead obiect cmdRead = new OleDbCommand(strField, cnn); cnn.Open(); datReader = cmdRead.ExecuteReader(); // fill ListView while (datReader.Read()) { ListViewItem objListItem = new ListViewItem(datReader.GetValue(0).ToString()); for (int c = 1; c < datReader.FieldCount; c++) { objListItem.SubItems.Add(datReader.GetValue(c).ToString()); } lvData.Items.Add(objListItem); } datReader.Close(); cnn.Close(); } private void ViewToolStripMenuItem_Click(object sender, EventArgs e) { DataConnection(); } public void tvData_AfterExpand(object sender, System.Windows.Forms.TreeViewEventArgs e) { string tabName; int fldCount; if (e.Node.Tag.ToString() == "Tables") { fldCount = e.Node.GetNodeCount(false); //column headers. int n = lvData.Width; double wid = n / fldCount; // width columnn for (int c = 0; c < fldCount; c++) { lvData.Columns.Add(e.Node.Nodes[c].Text, (int)wid, HorizontalAlignment.Left); } // gett table name tabName = e.Node.Text; FillListView(datCon, tabName); } } public void button1_Click(object sender, EventArgs e) { //TO DO?? } } I have a treeview populated with tables (nodes) from my database, and a listview which is populated with the data from my tables when I click on a table. As you can see I have a button1 on my form. When I click it I want it to display to me the structure of the table I selected in my treeview (a treeview node). Not too many details, just the name of the columns in my table, type of columns, primary keys. I've tried to follow many tutorials but I can t seem to manage it.

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  • Converting to async,await using async targeting package

    - by e4rthdog
    I have this: private void BtnCheckClick(object sender, EventArgs e) { var a = txtLot.Text; var b = cmbMcu.SelectedItem.ToString(); var c = cmbLocn.SelectedItem.ToString(); btnCheck.BackColor = Color.Red; var task = Task.Factory.StartNew(() => Dal.GetLotAvailabilityF41021(a, b, c)); task.ContinueWith(t => { btnCheck.BackColor = Color.Transparent; lblDescriptionValue.Text = t.Result.Description; lblItemCodeValue.Text = t.Result.Code; lblQuantityValue.Text = t.Result.AvailableQuantity.ToString(); },TaskScheduler .FromCurrentSynchronizationContext() ); LotFocus(true); } and i followed J. Skeet's advice to move into async,await in my .NET 4.0 app. I converted into this: private async void BtnCheckClick(object sender, EventArgs e) { var a = txtLot.Text; var b = cmbMcu.SelectedItem.ToString(); var c = cmbLocn.SelectedItem.ToString(); btnCheck.BackColor = Color.Red; JDEItemLotAvailability itm = await Task.Factory.StartNew(() => Dal.GetLotAvailabilityF41021(a, b, c)); btnCheck.BackColor = Color.Transparent; lblDescriptionValue.Text = itm.Description; lblItemCodeValue.Text = itm.Code; lblQuantityValue.Text = itm.AvailableQuantity.ToString(); LotFocus(true); } It works fine. What confuses me is that i could do it without using Task but just the method of my Dal. But that means that i must have modified my Dal method, which is something i dont want? I would appreciate if someone would explain to me in "plain" words if what i did is optimal or not and why. Thanks P.s. My dal method public bool CheckLotExistF41021(string _lot, string _mcu, string _locn) { using (OleDbConnection con = new OleDbConnection(this.conString)) { OleDbCommand cmd = new OleDbCommand(); cmd.CommandText = "select lilotn from proddta.f41021 " + "where lilotn = ? and trim(limcu) = ? and lilocn= ?"; cmd.Parameters.AddWithValue("@lotn", _lot); cmd.Parameters.AddWithValue("@mcu", _mcu); cmd.Parameters.AddWithValue("@locn", _locn); cmd.Connection = con; con.Open(); OleDbDataReader rdr = cmd.ExecuteReader(); bool _retval = rdr.HasRows; rdr.Close(); con.Close(); return _retval; } }

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  • I can't Open my excel file in c#

    - by Ruben Guico
    Hi, Below is my code, i tried to open my excel file in my c# application but the program give's me an error message "Cannot Access "my excel.xls". But when I specify the file path in my string path variable it works, the problem is I need to get the file path from an openFileDialog. using System; using System.IO; using System.Collections.Generic; using System.Text; using System.Data; using System.Windows.Forms; using System.Data.OleDb; using System.Reflection; using MOIE = Microsoft.Office.Interop.Excel; using OFFICE = Microsoft.Office.Core; namespace EmpUploader { public class ExcelCon { private OleDbDataReader reader = null; private OleDbCommand excelCommand = new OleDbCommand(); private OleDbDataAdapter adapter = new OleDbDataAdapter(); private DataTable excelData = new DataTable(); private MOIE.ApplicationClass objExcel = new MOIE.ApplicationClass(); private MOIE.Workbook wb = null; private string myConn = ""; private string strSQL = ""; private string err = ""; private string path2 = ""; private int sheetCount = 0; private OleDbConnection Con = new OleDbConnection(""); #region "excel interop prarameters" private static object xl_missing = Type.Missing; private static object xl_true = true; private static object xl_false = false; private object xl_update_links = xl_missing; private object xl_read_only = xl_missing; private object xl_format = xl_missing; private object xl_password = xl_missing; private object xl_write_res_password = xl_missing; private object xl_ignore_read_only = xl_missing; private object xl_origin = xl_missing; private object xl_delimiter = xl_missing; private object xl_editable = xl_missing; private object xl_notify = xl_missing; private object xl_converter = xl_missing; private object xl_add_to_mru = xl_missing; private object xl_local = xl_missing; private object xl_corrupt_load = xl_missing; #endregion } //MY CODE FOR OPENING THE EXCEL //note that my file path came from an openfiledialog public void InitializeConnection(string path) { //connection string for excel myConn = @"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" + path + "; Extended Properties =Excel 8.0"; Con.ConnectionString = myConn; Con.Open(); //this is the sample specified path that worked when i test my application //path = @"C:\shinetsu p5 emp list.xls"; objExcel.Visible = false; wb = objExcel.Workbooks.Open(path, xl_update_links, xl_read_only, xl_format, xl_password, xl_write_res_password, xl_ignore_read_only, xl_origin, xl_delimiter, xl_editable, xl_notify, xl_converter, xl_add_to_mru, xl_local, xl_corrupt_load); sheetCount = wb.Worksheets.Count; } }

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  • No value given for one or more required parameters in connection initialisation

    - by Jean-François Côté
    I have an C# form application that use an access database. This application works perfectly in debug and release. It works on all version of Windows. But it crash on one computer with Windows 7. The message I got is: System.Data.OleDb.OleDbException: No value given for one or more required parameters. EDIT, after some debugging with messagebox on the computer that have the problem, here is the code that bug.The error is catched on the cmd.ExecuteReader(). The messagebox juste before is shown and the next one is the one in the catch with the exception below. Any ideas? public List<CoeffItem> GetModeleCoeff() { List<CoeffItem> list = new List<CoeffItem>(); try { OleDbDataReader dr; OleDbCommand cmd = new OleDbCommand("SELECT nIDModelAquacad, nIDModeleBorne, fCoefficient FROM tbl_ModelBorne ORDER BY nIDModelAquacad", m_conn); MessageBox.Show("Commande SQL créée avec succès"); dr = cmd.ExecuteReader(); MessageBox.Show("Exécution du reader sans problème!"); while (dr.Read()) { list.Add(new CoeffItem(Convert.ToInt32(dr["nIDModelAquacad"].ToString()), Convert.ToInt32(dr["nIDModeleBorne"].ToString()), Convert.ToDouble(dr["fCoefficient"].ToString()))); } MessageBox.Show("Lecture du reader"); dr.Close(); MessageBox.Show("Fermeture du reader"); } catch (OleDbException err) { MessageBox.Show("Erreur dans la lecture des modèles/coefficient: " + err.ToString()); } return list; } I think it's something related to the connection string but why only on that computer. Thanks for your help! EDIT Here is the complete error message: See the end of this message for details on invoking just-in-time (JIT) debugging instead of this dialog box. ***** Exception Text ******* System.Data.OleDb.OleDbException: No value given for one or more required parameters. at System.Data.OleDb.OleDbCommand.ExecuteCommandTextErrorHandling(OleDbHResult hr) at System.Data.OleDb.OleDbCommand.ExecuteCommandTextForSingleResult(tagDBPARAMS dbParams, Object& executeResult) at System.Data.OleDb.OleDbCommand.ExecuteCommandText(Object& executeResult) at System.Data.OleDb.OleDbCommand.ExecuteCommand(CommandBehavior behavior, Object& executeResult) at System.Data.OleDb.OleDbCommand.ExecuteReaderInternal(CommandBehavior behavior, String method) at System.Data.OleDb.OleDbCommand.ExecuteReader(CommandBehavior behavior) at System.Data.OleDb.OleDbCommand.ExecuteReader() at DatabaseLayer.DatabaseFacade.GetModeleCoeff() at DatabaseLayer.DatabaseFacade.InitConnection(String strFile) at CalculatriceCHW.ListeMesure.OuvrirFichier(String strFichier) at CalculatriceCHW.ListeMesure.nouveauFichierMenu_Click(Object sender, EventArgs e) at System.Windows.Forms.ToolStripItem.RaiseEvent(Object key, EventArgs e) at System.Windows.Forms.ToolStripMenuItem.OnClick(EventArgs e) at System.Windows.Forms.ToolStripItem.HandleClick(EventArgs e) at System.Windows.Forms.ToolStripItem.HandleMouseUp(MouseEventArgs e) at System.Windows.Forms.ToolStripItem.FireEventInteractive(EventArgs e, ToolStripItemEventType met) at System.Windows.Forms.ToolStripItem.FireEvent(EventArgs e, ToolStripItemEventType met) at System.Windows.Forms.ToolStrip.OnMouseUp(MouseEventArgs mea) at System.Windows.Forms.ToolStripDropDown.OnMouseUp(MouseEventArgs mea) at System.Windows.Forms.Control.WmMouseUp(Message& m, MouseButtons button, Int32 clicks) at System.Windows.Forms.Control.WndProc(Message& m) at System.Windows.Forms.ScrollableControl.WndProc(Message& m) at System.Windows.Forms.ToolStrip.WndProc(Message& m) at System.Windows.Forms.ToolStripDropDown.WndProc(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m) at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m) at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)

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  • combobox with for each loop

    - by Mary
    Hi I am a student do anybody know after populating the combobox with the database values. How to display the same value in the text box. When I select a name in the combobox the same name should be displayed in the text box I am using seleted item. Here is the code. I am getting the error the following error using the foreach loop foreach statement cannot operate on variables of type 'object' because 'object' does not contain a public definition for 'GetEnumerator' using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using System.Data.OleDb; namespace DBExample { public partial class Form1 : Form { private OleDbConnection dbConn; // Connectionn object private OleDbCommand dbCmd; // Command object private OleDbDataReader dbReader;// Data Reader object private Member aMember; private string sConnection; // private TextBox tb1; // private TextBox tb2; private string sql; public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { try { // Construct an object of the OleDbConnection // class to store the connection string // representing the type of data provider // (database) and the source (actual db) sConnection = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=c:member.mdb"; dbConn = new OleDbConnection(sConnection); dbConn.Open(); // Construct an object of the OleDbCommand // class to hold the SQL query. Tie the // OleDbCommand object to the OleDbConnection // object sql = "Select * From memberTable Order " + "By LastName , FirstName "; dbCmd = new OleDbCommand(); dbCmd.CommandText = sql; dbCmd.Connection = dbConn; // Create a dbReader object dbReader = dbCmd.ExecuteReader(); while (dbReader.Read()) { aMember = new Member (dbReader["FirstName"].ToString(), dbReader["LastName"].ToString(), dbReader["StudentId"].ToString(), dbReader["PhoneNumber"].ToString()); // tb1.Text = dbReader["FirstName"].ToString(); // tb2.Text = dbReader["LastName"].ToString(); // tb1.Text = aMember.X().ToString(); //tb2.Text = aMember.Y(aMember.ID).ToString(); this.comboBox1.Items.Add(aMember.FirstName.ToString()); // this.listBox1.Items.Add(aMember.ToString()); // MessageBox.Show(aMember.ToString()); // Console.WriteLine(aMember.ToString()); } dbReader.Close(); dbConn.Close(); } catch (System.Exception exc) { MessageBox.Show("show" + exc); } } private void DbGUI_Load(object sender, EventArgs e) { } private void comboBox1_SelectedIndexChanged(object sender, EventArgs e) { this.textBox1.Text = comboBox1.SelectedItem.ToString(); textBox2.Text = string.Empty; foreach (var item in comboBox1.SelectedItem) textBox2.Text += item.ToString(); } private void textBox2_TextChanged(object sender, EventArgs e) { } private void textBox1_TextChanged(object sender, EventArgs e) { } } }

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