Develop Reference

Load data from database to string

I'm trying at the moment to get an information from a database and want to save it in a string, but yeah not sure about how really to do it right.
This is my code, where I open the LoadSql function:
public void LoadData(string KNR, string WNR, String filter)
{
// WHERE
const string sqlTemplate = "SELECT KUNDENAUFTRAGSNR FROM MESSFELD.AUSSTANDSDATEN WHERE FTNR = '" + txt_Barcode_read.Text + "'";
string sql = string.Format(sqlTemplate, filter);
Database cdb = new Database();
// try to connect and cancel on error
if (!cdb.Open("**********", "*********"))
{
SetStatusText("Datenbank ist nicht verfügbar.");
return;
}
WNR = cdb.LoadSql(sql);
cdb.Close();
}
And here is the LoadSQL function:
public DataTable LoadSql(string sql)
{
try
{
OracleCommand command = new OracleCommand(sql, _con);
command.InitialLONGFetchSize = -1;
OracleDataReader rdr = command.ExecuteReader();
DataTable dt = new DataTable();
dt.Load(rdr);
return dt;
}
catch
{
return null;
}
}
For the moment the LoadSQL is saving in datatable, how to change for saving the number in the string WNR?

You can re-write your LoadSQL function to something like this :
public string LoadSql(string sql)
{
try
{
OracleCommand command = new OracleCommand(sql, _con);
command.InitialLONGFetchSize = -1;
OracleDataReader rdr = command.ExecuteReader();
rdr.Read();
if(rdr.HasRows)
return rdr.GetString(0);
else
return "";
}
catch
{
return null;
}
}

No value given for one or more required parameters error - Excel

I am getting data from excel and showing it in DataGridWiew.
I have two textboxes, one is for starting index for first record and other is for last record.
Code works fine. But lets suppose starting record is 1 and ending is 10 when I change 10 to 1 or 2 it gives me an error in this line:
adapter.Fill(dataTable);
Full Code is below:
public DataSet Parse(string fileName)
{
string connectionString = string.Format("provider = Microsoft.Jet.OLEDB.4.0; data source = {0}; Extended Properties = Excel 8.0;", fileName);
DataSet data = new DataSet();
foreach (var sheetName in GetExcelSheetNames(connectionString))
{
using (OleDbConnection con = new OleDbConnection(connectionString))
{
string query = "";
var dataTable = new DataTable();
if(tbStarting.Text.Trim()=="" && tbEnding.Text.Trim() == "")
{
query = string.Format("SELECT * FROM [{0}]", sheetName);
}
else
{
query = string.Format("SELECT * FROM [{0}] where SrNo between " + int.Parse(tbStarting.Text.Trim()) + " and " + int.Parse(tbEnding.Text.Trim()) + " order by SrNo", sheetName);
}
con.Open();
OleDbDataAdapter adapter = new OleDbDataAdapter(query, con);
adapter.Fill(dataTable);
data.Tables.Add(dataTable);
con.Close();
}
}
return data;
}
static string[] GetExcelSheetNames(string connectionString)
{
OleDbConnection con = null;
DataTable dt = null;
con = new OleDbConnection(connectionString);
con.Open();
dt = con.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
if (dt == null)
{
return null;
}
String[] excelSheetNames = new String[dt.Rows.Count];
int i = 0;
foreach (DataRow row in dt.Rows)
{
excelSheetNames[i] = row["TABLE_NAME"].ToString();
i++;
}
return excelSheetNames;
}
Why this is happening please help me?

Looking at the code, it seems that your procedure is working when you ask to retrieve all the record in each table. But you are not showing which table (Sheet) is actually used afterwars.
Chances are, you are using the first one only.
When you submit some parameters, only one of the tables (Sheets) can fulfill those requirements. The other(s) don't, possibly because a field named [SrNo] is not present.
This causes the More Parameters Required error when trying to apply a filter.
Not related to the error, but worth noting: you don't need to recreate the whole DataSet + DataTables to filter your DataSources.
The DataSet.Tables[N].DefaultView.RowFilter can be used to get the same result without destroying all the objects each time a filter is required.
RowFilter has some limitations in the language (e.g. does not support BETWEEN, Field >= Value1 AND Field <= Value2 must be used), but it's quite effective.
This is a possible setup:
(xDataSet is a placeholder for your actual DataSet)
//Collect the values in the TextBoxes in a string array
private void button1_Click(object sender, EventArgs e)
{
string[] Ranges = new string[] { tbStarting.Text.Trim(), tbEnding.Text.Trim() };
if (xDataSet != null)
FilterDataset(Ranges);
}
private void FilterDataset(string[] Ranges)
{
if (string.IsNullOrEmpty(Ranges[0]) & string.IsNullOrEmpty(Ranges[1]))
xDataSet.Tables[0].DefaultView.RowFilter = null;
else if (string.IsNullOrEmpty(Ranges[0]) | string.IsNullOrEmpty(Ranges[1]))
return;
else if (int.Parse(Ranges[0]) < int.Parse(Ranges[1]))
xDataSet.Tables[0].DefaultView.RowFilter = string.Format("SrNo >= {0} AND SrNo <= {1}", Ranges[0], Ranges[1]);
else
xDataSet.Tables[0].DefaultView.RowFilter = string.Format("SrNo = {0}", Ranges[0]);
this.dataGridView1.Update();
}
I've modified your code you code a bit to handle those requirements.
(I've left here those filters anyway; they're not used, but if you still want them, they are in a working condition)
DataSet xDataSet = new DataSet();
string WorkBookPath = #"[Excel WorkBook Path]";
//Query one Sheet only. More can be added if necessary
string[] WBSheetsNames = new string[] { "Sheet1" };
//Open the Excel document and assign the DataSource to a dataGridView
xDataSet = Parse(WorkBookPath, WBSheetsNames, null);
dataGridView1.DataSource = xDataSet.Tables[0];
dataGridView1.Refresh();
public DataSet Parse(string fileName, string[] WorkSheets, string[] ranges)
{
if (!File.Exists(fileName)) return null;
string connectionString = string.Format("provider = Microsoft.ACE.OLEDB.12.0; " +
"data source = {0}; " +
"Extended Properties = \"Excel 12.0;HDR=YES\"",
fileName);
DataSet data = new DataSet();
string query = string.Empty;
foreach (string sheetName in GetExcelSheetNames(connectionString))
{
foreach (string WorkSheet in WorkSheets)
if (sheetName == (WorkSheet + "$"))
{
using (OleDbConnection con = new OleDbConnection(connectionString))
{
DataTable dataTable = new DataTable();
if ((ranges == null) ||
(string.IsNullOrEmpty(ranges[0]) || string.IsNullOrEmpty(ranges[1])) ||
(int.Parse(ranges[0]) > int.Parse(ranges[1])))
query = string.Format("SELECT * FROM [{0}]", sheetName);
else if ((int.Parse(ranges[0]) == int.Parse(ranges[1])))
query = string.Format("SELECT * FROM [{0}] WHERE SrNo = {1}", sheetName, ranges[0]);
else
query = string.Format("SELECT * FROM [{0}] WHERE (SrNo BETWEEN {1} AND {2}) " +
"ORDER BY SrNo", sheetName, ranges[0], ranges[1]);
con.Open();
OleDbDataAdapter adapter = new OleDbDataAdapter(query, con);
adapter.Fill(dataTable);
data.Tables.Add(dataTable);
};
}
}
return data;
}
static string[] GetExcelSheetNames(string connectionString)
{
string[] excelSheetNames = null;
using (OleDbConnection con = new OleDbConnection(connectionString))
{
con.Open();
using (DataTable dt = con.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null))
{
if (dt != null)
{
excelSheetNames = new string[dt.Rows.Count];
for (int i = 0; i < dt.Rows.Count; i++)
{
excelSheetNames[i] = dt.Rows[i]["TABLE_NAME"].ToString();
}
}
}
}
return excelSheetNames;
}

How To insert data into SQL Sever with C# without using the database wizard(visual studio)

I'm having trouble inserting data into my table called "client" in my database called "vet".
I'm trying to do the connection manually as opposed to using the database wizard. I want to do it this way so that i can hide the majority of my code in a separate class.
I have a feeling I have the logic for this all wrong as I'm not making use of a data set, I was hoping someone could point me in the right direction.
This is for a school assignment and not for real world use. I have read a number of similar posts but am still unable to come to a solution.
public void CommitToDatabase()
{
using (var con = new SqlConnection(CLSDatabaseDetails.GlobalConnectionString))
{
DataTable client = new DataTable();
DataSet ds = new DataSet();
string commandString = "SELECT * FROM client";
SqlCommand cmd = new SqlCommand(commandString, con);
con.Open();
SqlDataAdapter da = new SqlDataAdapter(cmd);
da.Fill(client);
DataRow newClientRow = ds.Tables["client"].NewRow();
newClientRow["ClientID"] = ClientID;
newClientRow["FirstName"] = FirstName;
newClientRow["LastName"] = LastName;
newClientRow["Phone"] = PhoneNumber;
newClientRow["CAddress"] = Address;
newClientRow["Email"] = Email;
newClientRow["CUsername"] = Username;
newClientRow["CPassword"] = Password;
client.Rows.Add(newClientRow);
da.Update(client);
}
}

A DataSet is a collection of DataTables. In your example, you're only referring to one table. The SqlDataAdapter.Fill method will populate either DataSet or DataTable. You're calling da.Fill(client) which is fine - it will fill the DataTable client. You could also call da.Fill(ds, "client") which will fill the DataSet ds. You can then extract your table via ds.Tables["client"]. Using a DataSet in this example is overkill, but you can show your tutor how a DataSet works.
You're filling the DataTable but then adding the new row with reference to the DataSet. But in your example, the DataSet ds has nothing in it, because you filled the DataTable not the DataSet. Try this:
DataSet ds = new DataSet();
string commandString = "SELECT TOP 0 * FROM client";
SqlCommand cmd = new SqlCommand(commandString, con);
con.Open();
SqlDataAdapter da = new SqlDataAdapter(cmd);
SqlCommandBuilder builder = new SqlCommandBuilder(da);
da.Fill(ds, "client");
DataTable client = ds.Tables["client"];
DataRow newClientRow = client.NewRow();
... ... ...
client.Rows.Add(newClientRow);
builder.GetInsertCommand();
da.Update(client);
If you only want to insert a row, you don't need to SELECT all the rows. If you SELECT TOP 0 * from client you'll get the column names (which you need) but without the overhead of returning all the rows.

Try something like this:
public void CommitToDatabase()
{
using (var con = new SqlConnection(CLSDatabaseDetails.GlobalConnectionString))
{
DataTable client = new DataTable();
string commandString = "SELECT * FROM client";
SqlCommand cmd = new SqlCommand(commandString, con);
con.Open();
SqlDataAdapter da = new SqlDataAdapter(cmd);
da.Fill(client);
DataRow newClientRow = client.NewRow();
newClientRow["ClientID"] = ClientID;
newClientRow["FirstName"] = FirstName;
newClientRow["LastName"] = LastName;
newClientRow["Phone"] = PhoneNumber;
newClientRow["CAddress"] = Address;
newClientRow["Email"] = Email;
newClientRow["CUsername"] = Username;
newClientRow["CPassword"] = Password;
client.Rows.Add(newClientRow);
da.Update(client);
}
}

I can't tell what the source of your data is. Anyway, here are two examples of moving data from a CSV file to SQL Server and from a DataGridView to SQL Server.
using Microsoft.VisualBasic;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
using System.Data.SqlClient;
using System.IO;
using Microsoft.VisualBasic.FileIO;
using System.Data.Odbc;
using System.Data.OleDb;
using System.Configuration;
public class Form1
{
private void Button1_Click(System.Object sender, System.EventArgs e)
{
dynamic headers = (from header in DataGridView1.Columns.Cast<DataGridViewColumn>()header.HeaderText).ToArray;
dynamic rows = from row in DataGridView1.Rows.Cast<DataGridViewRow>()where !row.IsNewRowArray.ConvertAll(row.Cells.Cast<DataGridViewCell>.ToArray, c => c.Value != null ? c.Value.ToString : "");
string str = "";
using (IO.StreamWriter sw = new IO.StreamWriter("C:\\Users\\Excel\\Desktop\\OrdersTest.csv")) {
sw.WriteLine(string.Join(",", headers));
//sw.WriteLine(String.Join(","))
foreach (void r_loopVariable in rows) {
r = r_loopVariable;
sw.WriteLine(string.Join(",", r));
}
sw.Close();
}
}
private void Button2_Click(System.Object sender, System.EventArgs e)
{
//Dim m_strConnection As String = "server='Server_Name';Initial Catalog='Database_Name';Trusted_Connection=True;"
//Catch ex As Exception
// MessageBox.Show(ex.ToString())
//End Try
//Dim objDataset1 As DataSet()
//Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
//Dim da As OdbcDataAdapter
System.Windows.Forms.OpenFileDialog OpenFile = new System.Windows.Forms.OpenFileDialog();
// Does something w/ the OpenFileDialog
string strFullPath = null;
string strFileName = null;
TextBox tbFile = new TextBox();
// Sets some OpenFileDialog box options
OpenFile.Filter = "CSV Files (*.csv)|*.csv|All files (*.*)|*.*";
// Shows only .csv files
OpenFile.Title = "Browse to file:";
// Title at the top of the dialog box
// Makes the open file dialog box show up
if (OpenFile.ShowDialog() == DialogResult.OK) {
strFullPath = OpenFile.FileName;
// Assigns variable
strFileName = Path.GetFileName(strFullPath);
// Checks to see if they've picked a file
if (OpenFile.FileNames.Length > 0) {
tbFile.Text = strFullPath;
// Puts the filename in the textbox
// The connection string for reading into data connection form
string connStr = null;
connStr = "Driver={Microsoft Text Driver (*.txt; *.csv)}; Dbq=" + Path.GetDirectoryName(strFullPath) + "; Extensions=csv,txt ";
// Sets up the data set and gets stuff from .csv file
OdbcConnection Conn = new OdbcConnection(connStr);
DataSet ds = default(DataSet);
OdbcDataAdapter DataAdapter = new OdbcDataAdapter("SELECT * FROM [" + strFileName + "]", Conn);
ds = new DataSet();
try {
DataAdapter.Fill(ds, strFileName);
// Fills data grid..
DataGridView1.DataSource = ds.Tables(strFileName);
// ..according to data source
// Catch and display database errors
} catch (OdbcException ex) {
OdbcError odbcError = default(OdbcError);
foreach ( odbcError in ex.Errors) {
MessageBox.Show(ex.Message);
}
}
// Cleanup
OpenFile.Dispose();
Conn.Dispose();
DataAdapter.Dispose();
ds.Dispose();
}
}
}
private void Button3_Click(System.Object sender, System.EventArgs e)
{
SqlConnection cnn = default(SqlConnection);
string connectionString = null;
string sql = null;
connectionString = "data source='Server_Name';" + "initial catalog='Database_Name';Trusted_Connection=True";
cnn = new SqlConnection(connectionString);
cnn.Open();
sql = "SELECT * FROM [Order Details]";
SqlDataAdapter dscmd = new SqlDataAdapter(sql, cnn);
DataSet ds = new DataSet();
dscmd.Fill(ds);
DataGridView1.DataSource = ds.Tables(0);
cnn.Close();
}
private void ProductsDataGridView_CellFormatting(object sender, System.Windows.Forms.DataGridViewCellFormattingEventArgs e)
{
if (e.ColumnIndex == DataGridView1.Columns(3).Index && e.Value != null) {
//
if (Convert.ToInt32(e.Value) < 10) {
e.CellStyle.BackColor = Color.OrangeRed;
e.CellStyle.ForeColor = Color.LightGoldenrodYellow;
}
//
}
//
}
//Private Sub ProductsDataGridView_CellFormatting(ByVal sender As Object, _
// ByVal e As System.Windows.Forms.DataGridViewCellFormattingEventArgs) _
// Handles DataGridView1.CellFormatting
// '
// If e.ColumnIndex = DataGridView1.Columns("DataGridViewTextBoxColumn8").Index _
// AndAlso e.Value IsNot Nothing Then
// '
// If CInt(e.Value) < 5 Then
// e.CellStyle.BackColor = Color.OrangeRed
// e.CellStyle.ForeColor = Color.LightGoldenrodYellow
// End If
// '
// End If
// '
//End Sub
//If e.ColumnIndex = ProductsDataGridView.Columns(4).Index _
//AndAlso e.Value IsNot Nothing Then
//'
// If CInt(e.Value) = 0 Then
// e.CellStyle.BackColor = Color.OrangeRed
// e.CellStyle.ForeColor = Color.LightGoldenrodYellow
// End If
//End If
// ''To (you need to change the column name)
// If e.ColumnIndex = ProductsDataGridView.Columns("YourColumnName").Index _
// AndAlso e.Value IsNot Nothing Then
//'
// If CInt(e.Value) = 0 Then
// e.CellStyle.BackColor = Color.OrangeRed
// e.CellStyle.ForeColor = Color.LightGoldenrodYellow
// End If
//End If
private void Button4_Click(System.Object sender, System.EventArgs e)
{
DataTable tblReadCSV = new DataTable();
tblReadCSV.Columns.Add("FName");
tblReadCSV.Columns.Add("LName");
tblReadCSV.Columns.Add("Department");
TextFieldParser csvParser = new TextFieldParser("C:\\Users\\Excel\\Desktop\\Employee.txt");
csvParser.Delimiters = new string[] { "," };
csvParser.TrimWhiteSpace = true;
csvParser.ReadLine();
while (!(csvParser.EndOfData == true)) {
tblReadCSV.Rows.Add(csvParser.ReadFields());
}
SqlConnection con = new SqlConnection("Server='Server_Name';Database='Database_Name';Trusted_Connection=True;");
string strSql = "Insert into Employee(FName,LName,Department) values(#Fname,#Lname,#Department)";
//Dim con As New SqlConnection(strCon)
SqlCommand cmd = new SqlCommand();
cmd.CommandType = CommandType.Text;
cmd.CommandText = strSql;
cmd.Connection = con;
cmd.Parameters.Add("#Fname", SqlDbType.VarChar, 50, "FName");
cmd.Parameters.Add("#Lname", SqlDbType.VarChar, 50, "LName");
cmd.Parameters.Add("#Department", SqlDbType.VarChar, 50, "Department");
SqlDataAdapter dAdapter = new SqlDataAdapter();
dAdapter.InsertCommand = cmd;
int result = dAdapter.Update(tblReadCSV);
}
private void Button5_Click(System.Object sender, System.EventArgs e)
{
string SQLConnectionString = "Data Source=Excel-PC\\SQLEXPRESS;" + "Initial Catalog=Northwind;" + "Trusted_Connection=True";
// Open a connection to the AdventureWorks database.
using (SqlConnection SourceConnection = new SqlConnection(SQLConnectionString)) {
SourceConnection.Open();
// Perform an initial count on the destination table.
SqlCommand CommandRowCount = new SqlCommand("SELECT COUNT(*) FROM dbo.Orders;", SourceConnection);
long CountStart = System.Convert.ToInt32(CommandRowCount.ExecuteScalar());
Console.WriteLine("Starting row count = {0}", CountStart);
// Get data from the source table as a AccessDataReader.
//Dim ConnectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
// "Data Source=" & "C:\Users\Excel\Desktop\OrdersTest.txt" & ";" & _
// "Extended Properties=" & "text;HDR=Yes;FMT=Delimited"","";"
string ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + "C:\\Users\\Excel\\Desktop\\" + ";" + "Extended Properties=\"Text;HDR=No\"";
System.Data.OleDb.OleDbConnection TextConnection = new System.Data.OleDb.OleDbConnection(ConnectionString);
OleDbCommand TextCommand = new OleDbCommand("SELECT * FROM OrdersTest#csv", TextConnection);
TextConnection.Open();
OleDbDataReader TextDataReader = TextCommand.ExecuteReader(CommandBehavior.SequentialAccess);
// Open the destination connection.
using (SqlConnection DestinationConnection = new SqlConnection(SQLConnectionString)) {
DestinationConnection.Open();
// Set up the bulk copy object.
// The column positions in the source data reader
// match the column positions in the destination table,
// so there is no need to map columns.
using (SqlBulkCopy BulkCopy = new SqlBulkCopy(DestinationConnection)) {
BulkCopy.DestinationTableName = "dbo.Orders";
try {
// Write from the source to the destination.
BulkCopy.WriteToServer(TextDataReader);
} catch (Exception ex) {
Console.WriteLine(ex.Message);
} finally {
// Close the AccessDataReader. The SqlBulkCopy
// object is automatically closed at the end
// of the Using block.
TextDataReader.Close();
}
}
// Perform a final count on the destination table
// to see how many rows were added.
long CountEnd = System.Convert.ToInt32(CommandRowCount.ExecuteScalar());
//Console.WriteLine("Ending row count = {0}", CountEnd)
//Console.WriteLine("{0} rows were added.", CountEnd - CountStart)
}
}
//Dim FILE_NAME As String = "C:\Users\Excel\Desktop\OrdersTest.csv"
//Dim TextLine As String
//If System.IO.File.Exists(FILE_NAME) = True Then
// Dim objReader As New System.IO.StreamReader(FILE_NAME)
// Do While objReader.Peek() <> -1
// TextLine = TextLine & objReader.ReadLine() & vbNewLine
// Loop
//Else
// MsgBox("File Does Not Exist")
//End If
//Dim cn As New SqlConnection("Data Source=Excel-PC\SQLEXPRESS;Initial Catalog=Northwind;Trusted_Connection=True;")
//Dim cmd As New SqlCommand
//cmd.Connection = cn
//cmd.Connection.Close()
//cmd.Connection.Open()
//cmd.CommandText = "INSERT INTO Orders (OrderID,CustomerID,EmployeeID,OrderDate,RequiredDate,ShippedDate,ShipVia,Freight,ShipName,ShipAddress,ShipCity,ShipRegion,ShipPostalCode,ShipCountry) values & OrdersTest.csv"
//cmd.ExecuteNonQuery()
//cmd.Connection.Close()
}
private void Button6_Click(System.Object sender, System.EventArgs e)
{
// Define the Column Definition
DataTable dt = new DataTable();
dt.Columns.Add("OrderID", typeof(int));
dt.Columns.Add("CustomerID", typeof(string));
dt.Columns.Add("EmployeeID", typeof(int));
dt.Columns.Add("OrderDate", typeof(System.DateTime));
dt.Columns.Add("RequiredDate", typeof(System.DateTime));
dt.Columns.Add("ShippedDate", typeof(System.DateTime));
dt.Columns.Add("ShipVia", typeof(int));
dt.Columns.Add("Freight", typeof(decimal));
dt.Columns.Add("ShipName", typeof(string));
dt.Columns.Add("ShipAddress", typeof(string));
dt.Columns.Add("ShipCity", typeof(string));
dt.Columns.Add("ShipRegion", typeof(string));
dt.Columns.Add("ShipPostalCode", typeof(string));
dt.Columns.Add("ShipCountry", typeof(string));
using (cn == new SqlConnection("Server='Server_Name';Database='Database_Name';Trusted_Connection=True;")) {
cn.Open();
Microsoft.VisualBasic.FileIO.TextFieldParser reader = default(Microsoft.VisualBasic.FileIO.TextFieldParser);
string[] currentRow = null;
DataRow dr = default(DataRow);
string sqlColumnDataType = null;
reader = My.Computer.FileSystem.OpenTextFieldParser("C:\\Users\\Excel\\Desktop\\OrdersTest.csv");
reader.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.Delimited;
reader.Delimiters = new string[] { "," };
while (!reader.EndOfData) {
try {
currentRow = reader.ReadFields();
dr = dt.NewRow();
for (currColumn = 0; currColumn <= dt.Columns.Count - 1; currColumn++) {
sqlColumnDataType = dt.Columns(currColumn).DataType.Name;
switch (sqlColumnDataType) {
case "String":
if (string.IsNullOrEmpty(currentRow(currColumn))) {
dr.Item(currColumn) = "";
} else {
dr.Item(currColumn) = Convert.ToString(currentRow(currColumn));
}
break;
case "Decimal":
if (string.IsNullOrEmpty(currentRow(currColumn))) {
dr.Item(currColumn) = 0;
} else {
dr.Item(currColumn) = Convert.ToDecimal(currentRow(currColumn));
}
break;
case "DateTime":
if (string.IsNullOrEmpty(currentRow(currColumn))) {
dr.Item(currColumn) = "";
} else {
dr.Item(currColumn) = Convert.ToDateTime(currentRow(currColumn));
}
break;
}
}
dt.Rows.Add(dr);
} catch (Microsoft.VisualBasic.FileIO.MalformedLineException ex) {
Interaction.MsgBox("Line " + ex.Message + "is not valid." + Constants.vbCrLf + "Terminating Read Operation.");
reader.Close();
reader.Dispose();
//Return False
} finally {
dr = null;
}
}
using (SqlBulkCopy copy = new SqlBulkCopy(cn)) {
copy.DestinationTableName = "[dbo].[Orders]";
copy.WriteToServer(dt);
}
}
}
public static bool GetCsvData(string CSVFileName, ref DataTable CSVTable)
{
Microsoft.VisualBasic.FileIO.TextFieldParser reader = default(Microsoft.VisualBasic.FileIO.TextFieldParser);
string[] currentRow = null;
DataRow dr = default(DataRow);
string sqlColumnDataType = null;
reader = My.Computer.FileSystem.OpenTextFieldParser(CSVFileName);
reader.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.Delimited;
reader.Delimiters = new string[] { "," };
while (!reader.EndOfData) {
try {
currentRow = reader.ReadFields();
dr = CSVTable.NewRow();
for (currColumn = 0; currColumn <= CSVTable.Columns.Count - 1; currColumn++) {
sqlColumnDataType = CSVTable.Columns(currColumn).DataType.Name;
switch (sqlColumnDataType) {
case "String":
if (string.IsNullOrEmpty(currentRow(currColumn))) {
dr.Item(currColumn) = "";
} else {
dr.Item(currColumn) = Convert.ToString(currentRow(currColumn));
}
break;
case "Decimal":
if (string.IsNullOrEmpty(currentRow(currColumn))) {
dr.Item(currColumn) = 0;
} else {
dr.Item(currColumn) = Convert.ToDecimal(currentRow(currColumn));
}
break;
case "DateTime":
if (string.IsNullOrEmpty(currentRow(currColumn))) {
dr.Item(currColumn) = "";
} else {
dr.Item(currColumn) = Convert.ToDateTime(currentRow(currColumn));
}
break;
}
}
CSVTable.Rows.Add(dr);
} catch (Microsoft.VisualBasic.FileIO.MalformedLineException ex) {
Interaction.MsgBox("Line " + ex.Message + "is not valid." + Constants.vbCrLf + "Terminating Read Operation.");
reader.Close();
reader.Dispose();
return false;
} finally {
dr = null;
}
}
reader.Close();
reader.Dispose();
return true;
}
}
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How to filter one dropdownlist based on another selection

I have the following code which populates the Topic dropdownlist and saves it to a cached table:
bookingData2 = new DataTable();
DataTable DTable_List = new DataTable();
string connString = #"";
string query2 = #"Select * from [DB].dbo.[top]";// columng #1 = Specialty and column #2 = Topic
using (SqlConnection conn = new SqlConnection(connString))
{
try
{
SqlCommand cmd = new SqlCommand(query2, conn);
SqlDataAdapter da = new SqlDataAdapter(query2, conn);
da.Fill(bookingData2);
HttpContext.Current.Cache["cachedtable2"] = bookingData2;
bookingData2.DefaultView.Sort = "Topic ASC";
Topic.DataSource = bookingData2.DefaultView.ToTable(true, "Topic"); // populate only with the Topic column
Topic.DataTextField = "Topic";
Topic.DataValueField = "Topic";
Topic.DataBind();
Topic.Items.Insert(0, new ListItem("All Topics", "All Topics"));
da.Dispose();
}
catch (Exception ex)
{
string error = ex.Message;
}
}
I have the following code which populates the Specialty dropdownlist and saves it to another cached table:
bookingData = new DataTable();
DataTable DTable_List = new DataTable();
string connString = #"";
string query = #"select * from [DB].dbo.[SP]";
using (SqlConnection conn = new SqlConnection(connString))
{
try
{
SqlCommand cmd = new SqlCommand(query, conn);
SqlDataAdapter da = new SqlDataAdapter(query, conn);
da.Fill(bookingData);
bookingData.DefaultView.Sort = "Specialty ASC";
Specialty.DataSource = bookingData.DefaultView.ToTable(true, "Specialty");
Specialty.DataTextField = "Specialty";
Specialty.DataValueField = "Specialty";
Specialty.DataBind();
Specialty.Items.Remove("All Specialties");
Specialty.Items.Insert(0, new ListItem("All Specialties", "All Specialties"));
da.Dispose();
}
catch (Exception ex)
{
string error = ex.Message;
}
}
How can I code the Specialty dropdownlist index change to do the following and save it to a cache table for quick access:
protected void Specialty_SelectedIndexChanged(object sender, EventArgs e)
{
//re-populate the Topic dropdownlist to display all the topics based on the following criteria:
--> Where the Specialty column is either "All Specialties" OR "{specialty selected index value}"
}

Save bookingData2 table in ViewState or Session (I won't recommend to use session though) if it's not too heavy. Otherwise, its better you cache it or query the database again to repopulate it.
Let's assume you save bookingData2 in ViewState as follows in Page_Load
ViewState["bookingData2"] = bookingData2; // This should be before the following line
Topic.DataSource = bookingData2.DefaultView.ToTable(true, "Topic");
Then in your SelectedIndexChanged event do something like this
protected void Specialty_SelectedIndexChanged(object sender, EventArgs e)
{
//re-populate the Topic dropdownlist to display all the topics based on the following criteria:
// Where the Specialty column is either "All Specialties" OR "{specialty selected index value}"
DataTable bookingData2 = (DataTable)ViewState["bookingData2"];
Topic.DataSource = bookingData2.Where(i => i.Specialty == "All Specialties" || i.Specialty == Specialty.SelectedValue).DefaultView.ToTable(true, "Topic"); // populate only with the Topic column
Topic.DataTextField = "Topic";
Topic.DataValueField = "Topic";
Topic.DataBind();
Topic.Items.Insert(0, new ListItem("All Topics", "All Topics"));
}
Update - With Cached object
Do following in Specialty_SelectedIndexChanged event instead of where we used ViewState before.
if (HttpRuntime.Current.Cache["cachedtable2"] != null)
{
DataTable bookingData2 = HttpRuntime.Current.Cache["cachedtable2"] as DataTable;
// Rest of the code
}
I haven't tried this code. Let me know if you find any issues.

This is what solved it for me:
protected void Topic_SelectedIndexChanged(object sender, EventArgs e)
{
try
{
if (Topic.SelectedIndex == 0)
{
string query = #"Specialty LIKE '%%'";
DataTable cacheTable = HttpContext.Current.Cache["cachedtable"] as DataTable;
DataTable filteredData = cacheTable.Select(query).CopyToDataTable<DataRow>();
filteredData.DefaultView.Sort = "Specialty ASC";
Specialty.DataSource = filteredData.DefaultView.ToTable(true, "Specialty");
Specialty.DataTextField = "Specialty";
Specialty.DataValueField = "Specialty";
Specialty.DataBind();
}
else
{
string qpopulate = #"[Topic] = '" + Topic.SelectedItem.Value + "' or [Topic] = 'All Topics'"; //#"Select * from [DB].dbo.[table2] where [Specialty] = '" + Specialty.SelectedItem.Value + "' or [Specialty] = 'All Specialties'";
DataTable cTable = HttpContext.Current.Cache["cachedtable2"] as DataTable;
DataTable fData = cTable.Select(qpopulate).CopyToDataTable<DataRow>();
if (fData.Rows.Count > 0)
{
fData.DefaultView.Sort = "Specialty ASC";
Specialty.DataSource = fData.DefaultView.ToTable(true, "Specialty");
Specialty.DataTextField = "Specialty";
Specialty.DataValueField = "Specialty";
Specialty.DataBind();
}
Specialty.Items.Insert(0, new ListItem("All Specialties", "All Specialties"));
}
}
catch (Exception ce)
{
string error = ce.Message;
}
}

C# OdbcDataReader or DataTable.Load column name issue

I was happy coding my application and I faced this issue that scary me a little bit.
I have a SQLite db file and when I try to read a table using the OdcbDataReader and load it into a table using the DataTable.Load I get different results on the column name depending on the application I'm working on.
Sometimes it returns table_name.column_name and sometimes it returns only column_name.
The code is only this:
public DataTable GetTable(string table_name)
{
table = null;
if (conn_str != null)
{
try
{
using (OdbcConnection conn = new OdbcConnection(conn_str.ToString()))
{
StringBuilder query = new StringBuilder();
query.Append("SELECT * ");
query.Append("FROM [");
query.Append(table_name + "]");
using (OdbcCommand cmd = new OdbcCommand(query.ToString(), conn))
{
conn.Open();
table = new DataTable();
using (OdbcDataReader dr = cmd.ExecuteReader())
{
DataSet ds = new DataSet();
ds.EnforceConstraints = false;
ds.Tables.Add(table);
table.Load(dr);
}
}
}
}
catch (Exception ex)
{
Debug.Print(ex.Message);
table = null;
}
}
return table;
}
The connection string used is exactly the same:
"DRIVER={SQLite3 ODBC Driver};DATABASE=databesename.db3;"
Any ideas why this is happening?

Don't resolve the issue but at least gives an workaround.
Adding a replace to column name to remove the table_name if the Reader insert it.
foreach (DataColumn col in table.Columns)
{
//Fix column names if the Reader insert the table name into the ColumnName
col.ColumnName = col.ColumnName.Replace(table_name + ".", "");
}
Code After the change:
public DataTable GetTable(string table_name)
{
table = null;
if (conn_str != null)
{
try
{
using (OdbcConnection conn = new OdbcConnection(conn_str.ToString()))
{
StringBuilder query = new StringBuilder();
query.Append("SELECT * ");
query.Append("FROM [");
query.Append(table_name + "]");
using (OdbcCommand cmd = new OdbcCommand(query.ToString(), conn))
{
conn.Open();
table = new DataTable();
using (OdbcDataReader dr = cmd.ExecuteReader())
{
DataSet ds = new DataSet();
ds.EnforceConstraints = false;
ds.Tables.Add(table);
table.Load(dr);
foreach (DataColumn col in table.Columns)
{
//Fix column names if the Reader insert the table name into the ColumnName
col.ColumnName = col.ColumnName.Replace(table_name + ".", "");
}
}
}
}
}
catch (Exception ex)
{
Debug.Print(ex.Message);
table = null;
}
}
return table;
}