binding muliple data from sql to label by choosing item in combobox - sql-server

how i bind multiple data from sql to label if i choose an item in combo box that is from sql this is my code:
Private Sub cmboCourse_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmboCourse.SelectedIndexChanged
If cmboCourse.Text = "ADVANCED COMPUTER TECHNICIAN" Then
callMe()
ElseIf cmboCourse.Text = "AUTOELECTRICITY" Then
callMe()
ElseIf cmboCourse.Text = "AUTOMOTIVE" Then
callMe()
End If
End Sub
Private Sub callMe()
Dim str As String = ("Data Source=PC1; User ID=sa; Password=pwd;Databasfriend")
Dim con As New SqlConnection(str)
Dim str1 As String = "SELECT * FROM tbl_course"
Dim da As New SqlDataAdapter(str1, con)
Dim dataset1 As New DataSet()
da.Fill(dataset1, "course")
lbl.DataBindings.Add("text", dataset1, "course.Course_Code")
end sub
and this is my table
Course_Code Course
ACT ADVANCED COMPUTER TECHNICIAN
AE AUTOELECTRICITY
AM AUTOMOTIVE
it binds only one data, i want to bind many data in a particular column example i choose a course AUTOMOTIVE in combo box how does course_code of AUTOMOTIVE binds to label and if i choose AUTOELECTRICITY how does course_code of AUTOELECTRICITY binds to the same label

This is not tested, let me know if it doesn't work.
Private Sub cmboCourse_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmboCourse.SelectedIndexChanged
callMe(cmboCourse.Text)
End Sub
Private Sub callMe(ByVal course as String)
Dim str As String = ("Data Source=PC1; User ID=sa; Password=pwd;Databasfriend")
Dim con As New SqlConnection(str)
Dim str1 As String = "SELECT * FROM tbl_course WHERE [Course]='" & course & "'"
Dim da As New SqlDataAdapter(str1, con)
Dim dataset1 As New DataSet()
da.Fill(dataset1, "tbl_course")
'lbl.DataBindings.Add("text", dataset1, "course.Course_Code")
If dataset1.Tables("tbl_course").Rows.Count > 0 Then
lbl.Text = dataset1.Tables("tbl_course").Rows(0)("Course_Code")
Else
MsgBox "Course [" & course & "] not found"
End If
End Sub
Please note that in your code, da.Fill(dataset1, "course") you specify the table to be 'course', while the select statement selects from 'tbl_course' table. I am assuming the latter is correct name.
Edit 1:
Bug fix
Edit 2:
Debugging

sc.Open()
Dim da As New SqlDataAdapter()
Dim dataset1 As New DataSet()
Dim sql As New SqlCommand("Select * from book where Title='" + cmbtit.Text + "'", sc)
da.SelectCommand = sql
da.SelectCommand.ExecuteNonQuery()
da.Fill(dataset1, "book")
If dataset1.Tables("book").Rows.Count > 0 Then
txtauthor.Text = dataset1.Tables("book").Rows(0)("Author")
Else
MsgBox("Author [" & cmbtit.Text & "] not found")
End If
sc.Close()
End Sub

Related

If statement to not allow insert statement to work because a cell is null

I want the code to not allow the complete button to work because the column of "StartTime" is null.
Attached is the code below:
Imports System.Data.SqlClient
Imports System.Data
Imports System.IO
Public Class Etask
Dim con As SqlConnection
Dim cmd As SqlCommand
Private Sub Etask_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Labelname.Text = login.mname
Dim str As String = "Data Source=ICECANDY;Initial Catalog=RestaurantDatabase;integrated security=true"
Dim con As New SqlConnection(str)
Dim com As String = "SELECT TaskID, Name, TaskAssigned, StartTime, FinishTime, Status
FROM dbo.Tasks
WHERE Name = '" & Labelname.Text & "'"
Dim Adpt As New SqlDataAdapter(com, con)
Dim ds As New DataSet()
Adpt.Fill(ds, "PosTable")
DataGridView1.DataSource = ds.Tables(0)
End Sub
Private Sub Etask_Resize(sender As Object, e As EventArgs) Handles Me.Resize
Panel1.Left = (Me.Width - Panel1.Width) / 2
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
refreshDGV()
End Sub
Public Sub refreshDGV()
Labelname.Text = login.mname
Dim str As String = "Data Source=ICECANDY;Initial Catalog=RestaurantDatabase;integrated security=true"
Dim con As New SqlConnection(str)
Dim com As String = "SELECT TaskID, Name, TaskAssigned, StartTime, FinishTime, Status
FROM dbo.Tasks
WHERE Name = '" & Labelname.Text & "'"
Dim Adpt As New SqlDataAdapter(com, con)
Dim ds As New DataSet()
Adpt.Fill(ds, "PosTable")
DataGridView1.DataSource = ds.Tables(0)
End Sub
'complete button
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim con As New SqlConnection("Data Source=ICECANDY;Initial Catalog=RestaurantDatabase;integrated security=true")
Dim query As String = "update Tasks set FinishTime=#FinishTime,Status=#Status where TaskID=#id"
con.Open()
cmd = New SqlCommand(query, con)
cmd.Parameters.Add("#id", SqlDbType.VarChar).Value = LabelID.Text
cmd.Parameters.Add("#FinishTime", SqlDbType.VarChar).Value = Label1.Text
cmd.Parameters.Add("#Status", SqlDbType.VarChar).Value = comboboxstatus.Text
cmd.ExecuteNonQuery()
con.Close()
MsgBox("Successfully updated!")
refreshDGV()
End Sub
Private Sub FillByToolStripButton_Click(sender As Object, e As EventArgs)
Try
Me.TasksTableAdapter.FillBy(Me.RestaurantDatabaseDataSet2.Tasks)
Catch ex As System.Exception
System.Windows.Forms.MessageBox.Show(ex.Message)
End Try
End Sub
Private Sub DataGridView1_CellClick(sender As Object, e As DataGridViewCellEventArgs) Handles DataGridView1.CellClick
Dim i As Integer
i = DataGridView1.CurrentRow.Index
Me.LabelID.Text = DataGridView1.Item(0, i).Value
End Sub
Private Sub btnstart_Click(sender As Object, e As EventArgs) Handles btnstart.Click
Dim con As New SqlConnection("Data Source=ICECANDY;Initial Catalog=RestaurantDatabase;integrated security=true")
Dim query As String = "update Tasks set StartTime=#StartTime,Status=#Status where TaskID=#id"
con.Open()
cmd = New SqlCommand(query, con)
cmd.Parameters.Add("#id", SqlDbType.VarChar).Value = LabelID.Text
cmd.Parameters.Add("#StartTime", SqlDbType.VarChar).Value = Label1.Text
cmd.Parameters.Add("#Status", SqlDbType.VarChar).Value = "Working on it!"
cmd.ExecuteNonQuery()
con.Close()
MsgBox("Successfully started!")
refreshDGV()
End Sub
Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
Label1.Text = Date.Now.ToString("dd MMM yyyy hh:mm:ss")
End Sub
End Class
This is what the application looks like:
I want the code to check for null data in the StartTime column. If its null, then the complete button won't work. Button1 is the button to complete a task.
ExecuteNonQuery returns an integer with the number of rows affected.
If you create the query so that it does not do an update if the column is NULL, then it will return 0, which you can check for.
Also, it is easier to put the connection string in just one place, so that if you need to change it you only have to do so once - it is too easy to miss an occurrence of the string and have to go and edit it again. Often, such data is stored in the settings for the program, but I've made it as a constant for this example:
Public Const CONNSTR As String = "Data Source=ICECANDY;Initial Catalog=RestaurantDatabase;integrated security=true"
'....
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim query As String = "UPDATE Tasks
SET FinishTime = #FinishTime, Status = #Status
WHERE TaskID = #id
AND StartTime IS NOT NULL"
Dim nRowsAffected = 0
Using con As New SqlConnection(CONNSTR),
cmd As New SqlCommand(query, con)
cmd.Parameters.Add("#id", SqlDbType.VarChar).Value = LabelID.Text
cmd.Parameters.Add("#FinishTime", SqlDbType.VarChar).Value = Label1.Text
cmd.Parameters.Add("#Status", SqlDbType.VarChar).Value = comboboxstatus.Text
con.Open()
nRowsAffected = cmd.ExecuteNonQuery()
End Using
If nRowsAffected = 0 Then
MsgBox("Database not updated - check for empty StartTime.")
Else
MsgBox("Successfully updated!")
End If
refreshDGV()
End Sub
The Using statement makes sure that "unmanaged resources" are released when it is done.

System.Data.SqlClient.SqlException: 'Incorrect syntax near '​'.'

I get this SQL Server error and I can't figure out where the trouble is:
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
xception Details: System.Data.SqlClient.SqlException: 'Incorrect syntax near '​'.'
Source Error: Line: 46
Error Line: cmdsql.ExecuteNonQuery()
Code:
Dim connexcel As OleDbConnection
Dim daexcel As OleDbDataAdapter
Dim dsexcel As DataSet
Dim cmdexcel As OleDbCommand
Dim drexcel As OleDbDataReader
Dim connsql As SqlConnection
Dim dasql As SqlDataAdapter
Dim dssql As DataSet
Dim cmdsql As SqlCommand
Dim drsql As SqlDataReader
Private Sub import_excel_to_sql_server_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Me.CenterToScreen()
End Sub
Private Sub BtnImpExcelFile_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnImpExcelFile.Click
On Error Resume Next
OpenFileDialog1.Filter = "(* .xls) | * .xls | (*. Xlsx) | *. xlsx | All files (*. *) | *. * "
OpenFileDialog1.ShowDialog()
FileAdd.Text = OpenFileDialog1.FileName
connexcel = New OleDbConnection("provider = Microsoft.ace.OLEDB.12.0; data source =" & FileAdd.Text & "; Extended Properties = Excel 8.0;")
connexcel.Open()
Dim dtSheets As DataTable = connexcel.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, Nothing)
Dim listSheet As New List(Of String)
Dim drSheet As DataRow
For Each drSheet In dtSheets.Rows
listSheet.Add(drSheet("TABLE_NAME").ToString())
Next
For Each sheet As String In listSheet
ExcelSheetList.Items.Add(sheet)
Next
End Sub
Private Sub ExcelSheetList_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ExcelSheetList.SelectedIndexChanged
daexcel = New OleDbDataAdapter("select * from [" & ExcelSheetList.Text & "]", connexcel)
dsexcel = New DataSet
daexcel.Fill(dsexcel)
DGVImpData.DataSource = dsexcel.Tables(0)
DGVImpData.ReadOnly = True
End Sub
Sub connections()
connsql = New SqlConnection("data source =. \ MSSMLBIZ; initial catalog = MyInvoice; integrated security = true")
connsql.Open()
End Sub
Private Sub BtnSaveImpData_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnSaveImpData.Click
For line As Integer = 0 To DGVImpData.RowCount - 2
Call connections()
Dim save As String = "insert into InvoiceData values ​​('" & DGVImpData.Rows(line).Cells(0).Value & "', '" & DGVImpData.Rows(line).Cells(1).Value & "')"
cmdsql = New SqlCommand(save, connsql)
cmdsql.ExecuteNonQuery()
Next
MsgBox("data saved successfully")
DGVImpData.Columns.Clear()
End Sub
Keep your database objects local so you can be sure they are closed and disposed. Enclosing these objects with `Using...End Using blocks will accomplish this even if there is an error. You don't need variables for DataAdapters, DataSets, or DataReaders. I suggest only one form level variable for the Excel connection string since it is used in 2 methods.
A little bit of Linq will get the retrieved sheet names from the DataTable and fill an array. The array can then be passed to the list box with .AddRange.
I wouldn't use the SelectedIndexChanged event because the user can too easily click the wrong sheet or change their mind. I used a Button.Click event to fill the grid.
The Sql connection string looks strange to me. I suggest you test it separately. If it doesn't work, this is a good resource. https://www.connectionstrings.com/
I would specifically state the column names in the Insert statement. Replace FirstColumnName and SecondColumnName with the real column names. The parameter names can be anything you wish as long as the names in the statement match the names in the Parameters.Add method. I have guessed at the datatypes and the size. Check your database for correct values.
We add the parameters only once outside the loop then change only values inside the loop.
Private ExcelConString As String
Private Sub BtnImpExcelFile_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnImpExcelFile.Click
Dim strFileName As String
Dim dtSheets As DataTable
OpenFileDialog1.Filter = "(* .xls) | * .xls | (*. Xlsx) | *. xlsx | All files (*. *) | *. * "
OpenFileDialog1.ShowDialog()
strFileName = OpenFileDialog1.FileName
ExcelConString = "provider = Microsoft.ace.OLEDB.12.0; data source =" & strFileName & "; Extended Properties = Excel 8.0;"
Using connexcel = New OleDbConnection(ExcelConString)
connexcel.Open()
dtSheets = connexcel.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, Nothing)
End Using
Dim exSheets() As Object = (From dRow In dtSheets.AsEnumerable() Select dRow("TABLE_Name")).ToArray
ExcelSheetList.Items.AddRange(exSheets)
End Sub
Private Sub DisplayData_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles DisplayData.Click
Dim dt As New DataTable
Using cn As New OleDbConnection(ExcelConString)
'In older versions of Visual Studio you may have to use String.Format instead of the interpolated string.
Using cmd As New OleDbCommand($"select * from [{ExcelSheetList.Text}];", cn)
cn.Open()
dt.Load(cmd.ExecuteReader)
End Using
End Using
DGVImpData.DataSource = dt
DGVImpData.ReadOnly = True
End Sub
Private Sub BtnSaveImpData_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnSaveImpData.Click
Using cn As New SqlConnection("data source =. \ MSSMLBIZ; initial catalog = MyInvoice; integrated security = true")
Using cmd As New SqlCommand("Insert Into InvoiceData (FirstColumnName, SecondColumnName) Values ​​(#FirstColumn, #SecondColumn);", cn)
cmd.Parameters.Add("#FirstColumn", SqlDbType.VarChar, 100)
cmd.Parameters.Add("#SecondColumn", SqlDbType.VarChar, 100)
cn.Open()
For line As Integer = 0 To DGVImpData.RowCount - 2
cmd.Parameters("#FirstColumn").Value = DGVImpData.Rows(line).Cells(0).Value
cmd.Parameters("#SecondColumn").Value = DGVImpData.Rows(line).Cells(1).Value
cmd.ExecuteNonQuery()
Next
End Using
End Using
MsgBox("data saved successfully")
DGVImpData.Columns.Clear()
End Sub
As to error handling... On Error Resume Next is generally not used in new code. We have Try...Catch...Finally blocks. After your code is running add these blocks where needed.
EDIT
To use String.Format...
Using cmd As New OleDbCommand(String.Format("select * from [{0}];", ExcelSheetList.Text))
The first parameter is the string in which you wish to place variables. It contains indexed placeholders enclosed in braces. The following parameters are the variables you want for the placeholder substitution.
Thank you for helping me to a fixed error in my code. Here is Final code without System.Data.SqlClient.SqlException: 'Incorrect syntax near '​'.' error.
Now I tried to improve code with the last section(mention below) to define parameters for exporting data. Because I have a large number of data for exporting to SQL Server I get a Timeout error. Can anyone be able to improve code for quick exporting data to SQL Server?
connsql.Open() "System.InvalidOperationException: 'Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached.'"
Dim connexcel As OleDbConnection
Dim daexcel As OleDbDataAdapter
Dim dsexcel As DataSet
Dim cmdexcel As OleDbCommand
Dim drexcel As OleDbDataReader
Dim connsql As SqlConnection
Dim dasql As SqlDataAdapter
Dim dssql As DataSet
Dim cmdsql As SqlCommand
Dim drsql As SqlDataReader
Private Sub Import_excel_to_sql_server_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Me.CenterToScreen()
End Sub
Private Sub PKGAbtnImpExcelFile_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PKGAbtnImpExcelFile.Click
On Error Resume Next
'OpenFileDialog1.Filter = "(*.xls)|*.xls|(*.xlsx)|*.xlsx|All files (*.*)|*.*"
PKGAofdImpOpenExcel.ShowDialog()
PKGAtxtImpFileAdd.Text = PKGAofdImpOpenExcel.FileName
connexcel = New OleDbConnection("provider=Microsoft.ace.OLEDB.12.0;data source=" & PKGAtxtImpFileAdd.Text & ";Extended Properties=Excel 8.0;")
connexcel.Open()
Dim dtSheets As DataTable = connexcel.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, Nothing)
Dim listSheet As New List(Of String)
Dim drSheet As DataRow
For Each drSheet In dtSheets.Rows
listSheet.Add(drSheet("TABLE_NAME").ToString())
Next
For Each sheet As String In listSheet
PKGAtxtImpExlSheetL.Items.Add(sheet)
Next
End Sub
Private Sub PKGAtxtImpExlSheetL_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PKGAtxtImpExlSheetL.SelectedIndexChanged
daexcel = New OleDbDataAdapter("select * from [" & PKGAtxtImpExlSheetL.Text & "]", connexcel)
dsexcel = New DataSet
daexcel.Fill(dsexcel)
PKGAdgvImpData.DataSource = dsexcel.Tables(0)
PKGAdgvImpData.ReadOnly = True
End Sub
'Last Section
Sub Connectonsql()
connsql = New SqlConnection("Data Source=DESKTOP-MIQGJTK\MSSMLBIZ;Initial Catalog=PkGlobalAccounting;Integrated Security=True")
connsql.Open()
End Sub
Private Sub PKGAbtnImpSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PKGAbtnImpSave.Click
For Line As Integer = 0 To PKGAdgvImpData.RowCount - 2
Call Connectonsql()
Dim save As String = "insert into Test values('" & PKGAdgvImpData.Rows(Line).Cells(0).Value & "','" & PKGAdgvImpData.Rows(Line).Cells(1).Value & "')"
cmdsql = New SqlCommand(save, connsql)
cmdsql.ExecuteNonQuery()
Next
MsgBox("Data Saved Successfully")
PKGAdgvImpData.Columns.Clear()
End Sub
Thanks for Your Help.

Unable to convert System.Date and System.int to System.String, error

I'm trying to search a keyword in the SQL Server db from Textbox1 and printing the corresponding details in other TextBoxes.
While running the below code, it shows it is unable to convert the DateTime and Integer value into String to display it in the TextBoxes.
Also there is another end of statement expected error in the command.Parameter line:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim connection As New SqlConnection("Server= DESKTOP-STMQUHM; Database = HospitalDB;Trusted_Connection=True")
Dim command As New SqlCommand("select * from Medicines where MedicineName ='" & TextBox1.Text & "' ", connection)
command.Parameters.Add("#Textbox1",SqlDbType.Text)Value=TextBox1.Text 'Another error
Dim adapter As New SqlDataAdapter(command)
Dim table As New DataTable()
adapter.Fill(table)
TextBox1.Text = ""
TextBox2.Text = ""
TextBox3.Text = ""
TextBox4.Text = ""
If table.Rows.Count() > 0 Then
TextBox1.Text = table.Rows(0)(1).ToString
TextBox2.Text = table.Rows(0)(2).ToString
TextBox3.Text = table.Rows(0)(3).ToString
TextBox4.Text = table.Rows(0)(4).ToString
Else
MessageBox.Show("NO DATA FOUND!!")
End If
End Sub
Try to change this:
Dim command As New SqlCommand("select * from Medicines where MedicineName ='" & TextBox1.Text & "' ", connection)
command.Parameters.Add("#Textbox1",SqlDbType.Text)Value=TextBox1.Text
Into this:
Dim command As New SqlCommand("select * from Medicines where MedicineName = #MedicineName", connection)
command.Parameters.Add("#MedicineName",SqlDbType.Text).Value=TextBox1.Text
This is because you have not declared the parameter name into your original SQL string, then on the second line of your code, before Value, you're missing a dot.

How to import text file in vb.net and insert into SQL server?

I'm trying to import a text file into an SQL server. I need to read data inside the file when I upload it and send all the data to an SQL server. Of course inside the SQL I have primary keys where it's going to increment when a new line of data is finished.
HELP!
With Cinchoo ETL - an open source ETL framework, you can load the entire file to database with few lines of code as below (the code is in c#, hope you can translate it to vb.net)
string connectionstring =
#"Data Source=(localdb)\v11.0;Initial Catalog=TestDb;Integrated Security=True";
using (SqlBulkCopy bcp = new SqlBulkCopy(connectionstring))
{
using (var dr = new ChoCSVReader<Customer>
("Cust.csv").WithFirstLineHeader().AsDataReader())
{
bcp.DestinationTableName = "dbo.Customers";
bcp.EnableStreaming = true;
bcp.BatchSize = 10000;
bcp.BulkCopyTimeout = 0;
bcp.NotifyAfter = 10;
bcp.SqlRowsCopied += delegate (object sender, SqlRowsCopiedEventArgs e)
{
Console.WriteLine(e.RowsCopied.ToString("#,##0") + " rows copied.");
};
bcp.WriteToServer(dr);
}
}
For more details, visit the codeproject article
Disclosure: I'm the author of this library.
This is an interesting question. I did this a looonnngggg time ago. See the code below, for a solution to your question.
Private Sub Button4_Click(sender As System.Object, e As System.EventArgs) Handles Button4.Click
Dim tblReadCSV As New DataTable()
tblReadCSV.Columns.Add("FName")
tblReadCSV.Columns.Add("LName")
tblReadCSV.Columns.Add("Department")
Dim csvParser As New TextFieldParser("C:\Users\Excel\Desktop\Employee.txt")
csvParser.Delimiters = New String() {","}
csvParser.TrimWhiteSpace = True
csvParser.ReadLine()
While Not (csvParser.EndOfData = True)
tblReadCSV.Rows.Add(csvParser.ReadFields())
End While
Dim con As New SqlConnection("Server=Excel-PC\SQLEXPRESS;Database=Northwind;Trusted_Connection=True;")
Dim strSql As String = "Insert into Employee(FName,LName,Department) values(#Fname,#Lname,#Department)"
'Dim con As New SqlConnection(strCon)
Dim cmd As 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")
Dim dAdapter As New SqlDataAdapter()
dAdapter.InsertCommand = cmd
Dim result As Integer = dAdapter.Update(tblReadCSV)
End Sub
Also, see ALL the code below, for several similar, and related, tasks. Notice, I added a few comments, but not too many...
Imports System.Data.SqlClient
Imports System.IO
Imports Microsoft.VisualBasic.FileIO
Imports System.Data
Imports System.Data.Odbc
Imports System.Data.OleDb
Imports System.Configuration
Public Class Form1
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim headers = (From header As DataGridViewColumn In DataGridView1.Columns.Cast(Of DataGridViewColumn)() Select header.HeaderText).ToArray
Dim rows = From row As DataGridViewRow In DataGridView1.Rows.Cast(Of DataGridViewRow)() Where Not row.IsNewRow Select Array.ConvertAll(row.Cells.Cast(Of DataGridViewCell).ToArray, Function(c) If(c.Value IsNot Nothing, c.Value.ToString, ""))
Dim str As String = ""
Using sw As New IO.StreamWriter("C:\Users\Excel\Desktop\OrdersTest.csv")
sw.WriteLine(String.Join(",", headers))
'sw.WriteLine(String.Join(","))
For Each r In rows
sw.WriteLine(String.Join(",", r))
Next
sw.Close()
End Using
End Sub
Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
'Dim m_strConnection As String = "server=Excel-PC\SQLEXPRESS;Initial Catalog=Northwind;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
Dim OpenFile As New System.Windows.Forms.OpenFileDialog ' Does something w/ the OpenFileDialog
Dim strFullPath As String, strFileName As String
Dim tbFile As 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
If OpenFile.ShowDialog() = DialogResult.OK Then ' Makes the open file dialog box show up
strFullPath = OpenFile.FileName ' Assigns variable
strFileName = Path.GetFileName(strFullPath)
If OpenFile.FileNames.Length > 0 Then ' Checks to see if they've picked a file
tbFile.Text = strFullPath ' Puts the filename in the textbox
' The connection string for reading into data connection form
Dim connStr As String
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
Dim Conn As New OdbcConnection(connStr)
Dim ds As DataSet
Dim DataAdapter As 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 ex As OdbcException
Dim odbcError As OdbcError
For Each odbcError In ex.Errors
MessageBox.Show(ex.Message)
Next
End Try
' Cleanup
OpenFile.Dispose()
Conn.Dispose()
DataAdapter.Dispose()
ds.Dispose()
End If
End If
End Sub
Private Sub Button3_Click(sender As System.Object, e As System.EventArgs) Handles Button3.Click
Dim cnn As SqlConnection
Dim connectionString As String
Dim sql As String
connectionString = "data source=Excel-PC\SQLEXPRESS;" & _
"initial catalog=NORTHWIND;Trusted_Connection=True"
cnn = New SqlConnection(connectionString)
cnn.Open()
sql = "SELECT * FROM [Order Details]"
Dim dscmd As New SqlDataAdapter(sql, cnn)
Dim ds As New DataSet
dscmd.Fill(ds)
DataGridView1.DataSource = ds.Tables(0)
cnn.Close()
End Sub
Private Sub ProductsDataGridView_CellFormatting(ByVal sender As Object,
ByVal e As System.Windows.Forms.DataGridViewCellFormattingEventArgs) _
Handles DataGridView1.CellFormatting
If e.ColumnIndex = DataGridView1.Columns(3).Index _
AndAlso e.Value IsNot Nothing Then
'
If CInt(e.Value) < 10 Then
e.CellStyle.BackColor = Color.OrangeRed
e.CellStyle.ForeColor = Color.LightGoldenrodYellow
End If
'
End If
'
End Sub
Private Sub Button4_Click(sender As System.Object, e As System.EventArgs) Handles Button4.Click
Dim tblReadCSV As New DataTable()
tblReadCSV.Columns.Add("FName")
tblReadCSV.Columns.Add("LName")
tblReadCSV.Columns.Add("Department")
Dim csvParser As New TextFieldParser("C:\Users\Excel\Desktop\Employee.txt")
csvParser.Delimiters = New String() {","}
csvParser.TrimWhiteSpace = True
csvParser.ReadLine()
While Not (csvParser.EndOfData = True)
tblReadCSV.Rows.Add(csvParser.ReadFields())
End While
Dim con As New SqlConnection("Server=Excel-PC\SQLEXPRESS;Database=Northwind;Trusted_Connection=True;")
Dim strSql As String = "Insert into Employee(FName,LName,Department) values(#Fname,#Lname,#Department)"
'Dim con As New SqlConnection(strCon)
Dim cmd As 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")
Dim dAdapter As New SqlDataAdapter()
dAdapter.InsertCommand = cmd
Dim result As Integer = dAdapter.Update(tblReadCSV)
End Sub
Private Sub Button5_Click(sender As System.Object, e As System.EventArgs) Handles Button5.Click
Dim SQLConnectionString As String = "Data Source=Excel-PC\SQLEXPRESS;" & _
"Initial Catalog=Northwind;" & _
"Trusted_Connection=True"
' Open a connection to the AdventureWorks database.
Using SourceConnection As SqlConnection = _
New SqlConnection(SQLConnectionString)
SourceConnection.Open()
' Perform an initial count on the destination table.
Dim CommandRowCount As New SqlCommand( _
"SELECT COUNT(*) FROM dbo.Orders;", _
SourceConnection)
Dim CountStart As Long = _
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"","";"
Dim ConnectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=" & "C:\Users\Excel\Desktop\" & ";" & _
"Extended Properties=""Text;HDR=No"""
Dim TextConnection As New System.Data.OleDb.OleDbConnection(ConnectionString)
Dim TextCommand As New OleDbCommand("SELECT * FROM OrdersTest#csv", TextConnection)
TextConnection.Open()
Dim TextDataReader As OleDbDataReader = TextCommand.ExecuteReader(CommandBehavior.SequentialAccess)
' Open the destination connection.
Using DestinationConnection As SqlConnection = _
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 BulkCopy As SqlBulkCopy = _
New SqlBulkCopy(DestinationConnection)
BulkCopy.DestinationTableName = _
"dbo.Orders"
Try
' Write from the source to the destination.
BulkCopy.WriteToServer(TextDataReader)
Catch ex As Exception
Console.WriteLine(ex.Message)
Finally
' Close the AccessDataReader. The SqlBulkCopy
' object is automatically closed at the end
' of the Using block.
TextDataReader.Close()
End Try
End Using
' Perform a final count on the destination table
' to see how many rows were added.
Dim CountEnd As Long = _
System.Convert.ToInt32(CommandRowCount.ExecuteScalar())
'Console.WriteLine("Ending row count = {0}", CountEnd)
'Console.WriteLine("{0} rows were added.", CountEnd - CountStart)
End Using
End Using
'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()
End Sub
Private Sub Button6_Click(sender As System.Object, e As System.EventArgs) Handles Button6.Click
' Define the Column Definition
Dim dt As New DataTable()
dt.Columns.Add("OrderID", GetType(Integer))
dt.Columns.Add("CustomerID", GetType(String))
dt.Columns.Add("EmployeeID", GetType(Integer))
dt.Columns.Add("OrderDate", GetType(Date))
dt.Columns.Add("RequiredDate", GetType(Date))
dt.Columns.Add("ShippedDate", GetType(Date))
dt.Columns.Add("ShipVia", GetType(Integer))
dt.Columns.Add("Freight", GetType(Decimal))
dt.Columns.Add("ShipName", GetType(String))
dt.Columns.Add("ShipAddress", GetType(String))
dt.Columns.Add("ShipCity", GetType(String))
dt.Columns.Add("ShipRegion", GetType(String))
dt.Columns.Add("ShipPostalCode", GetType(String))
dt.Columns.Add("ShipCountry", GetType(String))
Using cn = New SqlConnection("Server=Excel-PC\SQLEXPRESS;Database=Northwind;Trusted_Connection=True;")
cn.Open()
Dim reader As Microsoft.VisualBasic.FileIO.TextFieldParser
Dim currentRow As String()
Dim dr As DataRow
Dim sqlColumnDataType As String
reader = My.Computer.FileSystem.OpenTextFieldParser("C:\Users\Excel\Desktop\OrdersTest.csv")
reader.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.Delimited
reader.Delimiters = New String() {","}
While Not reader.EndOfData
Try
currentRow = reader.ReadFields()
dr = dt.NewRow()
For currColumn = 0 To dt.Columns.Count - 1
sqlColumnDataType = dt.Columns(currColumn).DataType.Name
Select Case sqlColumnDataType
Case "String"
If String.IsNullOrEmpty(currentRow(currColumn)) Then
dr.Item(currColumn) = ""
Else
dr.Item(currColumn) = Convert.ToString(currentRow(currColumn))
End If
Case "Decimal"
If String.IsNullOrEmpty(currentRow(currColumn)) Then
dr.Item(currColumn) = 0
Else
dr.Item(currColumn) = Convert.ToDecimal(currentRow(currColumn))
End If
Case "DateTime"
If String.IsNullOrEmpty(currentRow(currColumn)) Then
dr.Item(currColumn) = ""
Else
dr.Item(currColumn) = Convert.ToDateTime(currentRow(currColumn))
End If
End Select
Next
dt.Rows.Add(dr)
Catch ex As Microsoft.VisualBasic.FileIO.MalformedLineException
MsgBox("Line " & ex.Message & "is not valid." & vbCrLf & "Terminating Read Operation.")
reader.Close()
reader.Dispose()
'Return False
Finally
dr = Nothing
End Try
End While
Using copy As New SqlBulkCopy(cn)
copy.DestinationTableName = "[dbo].[Orders]"
copy.WriteToServer(dt)
End Using
End Using
End Sub
Private Sub Button7_Click(sender As System.Object, e As System.EventArgs) Handles Button7.Click
'Dim cnn As SqlConnection
'Dim connectionString As String
'Dim sql As String
'connectionString = "data source=Excel-PC\SQLEXPRESS;" & _
'"initial catalog=NORTHWIND;Trusted_Connection=True"
'cnn = New SqlConnection(connectionString)
'cnn.Open()
'GetCsvData("C:\Users\Excel\Desktop\OrdersTest.csv", dbo.Orders)
End Sub
Public Shared Function GetCsvData(ByVal CSVFileName As String, ByRef CSVTable As DataTable) As Boolean
Dim reader As Microsoft.VisualBasic.FileIO.TextFieldParser
Dim currentRow As String()
Dim dr As DataRow
Dim sqlColumnDataType As String
reader = My.Computer.FileSystem.OpenTextFieldParser(CSVFileName)
reader.TextFieldType = Microsoft.VisualBasic.FileIO.FieldType.Delimited
reader.Delimiters = New String() {","}
While Not reader.EndOfData
Try
currentRow = reader.ReadFields()
dr = CSVTable.NewRow()
For currColumn = 0 To CSVTable.Columns.Count - 1
sqlColumnDataType = CSVTable.Columns(currColumn).DataType.Name
Select Case sqlColumnDataType
Case "String"
If String.IsNullOrEmpty(currentRow(currColumn)) Then
dr.Item(currColumn) = ""
Else
dr.Item(currColumn) = Convert.ToString(currentRow(currColumn))
End If
Case "Decimal"
If String.IsNullOrEmpty(currentRow(currColumn)) Then
dr.Item(currColumn) = 0
Else
dr.Item(currColumn) = Convert.ToDecimal(currentRow(currColumn))
End If
Case "DateTime"
If String.IsNullOrEmpty(currentRow(currColumn)) Then
dr.Item(currColumn) = ""
Else
dr.Item(currColumn) = Convert.ToDateTime(currentRow(currColumn))
End If
End Select
Next
CSVTable.Rows.Add(dr)
Catch ex As Microsoft.VisualBasic.FileIO.MalformedLineException
MsgBox("Line " & ex.Message & "is not valid." & vbCrLf & "Terminating Read Operation.")
reader.Close()
reader.Dispose()
Return False
Finally
dr = Nothing
End Try
End While
reader.Close()
reader.Dispose()
Return True
End Function
Private Sub DataGridView1_RowValidating(ByVal sender As Object, ByVal e As DataGridViewCellCancelEventArgs)
End Sub
End Class
One more to try . . .
Public Class Form1
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim file As String = "Import.txt"
Dim path As String = "C:\Users\path_to_text_file\"
Dim ds As New DataSet
Try
If IO.File.Exists(IO.Path.Combine(path, file)) Then
Dim ConStr As String = _
"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & _
path & ";Extended Properties=""Text;HDR=No;FMT=Delimited\"""
Dim conn As New OleDb.OleDbConnection(ConStr)
Dim da As New OleDb.OleDbDataAdapter("Select * from " & _
file, conn)
da.Fill(ds, "TextFile")
End If
Catch ex As Exception
MessageBox.Show(ex.ToString)
End Try
DataGridView1.DataSource = ds.Tables(0)
End Sub
Private Sub DataGridView1_CellContentClick(sender As Object, e As DataGridViewCellEventArgs) Handles DataGridView1.CellContentClick
End Sub
End Class

Multiple choice quiz that retrieves data from a database - how to make values from database go into random radiobuttons?

I am creating a multiple choice quiz that gets its questions and answers from an access database.
So far I have managed to connect the database to the form and input the questions into the radiobuttons.
I can mark the question but so far I haven't figured out how to randomise the database fields to go into different radiobuttons. I don't want the actual answer being in the same radiobutton throughout the loop of the questions.
Attached is a picture of the form pic
below is the code I use.
button1 is the next button
button2 is the back button
button3 is the save button
button4 is the return to last form button
button5 is the start button
Imports System.Data.OleDb
Public Class Form1
Dim ConnectString As String = "Provider=Microsoft.ACE.OLEDB.12.0;" & _
" Data Source= C:\Users\Sales\Documents\Visual Studio 2010\Normalised Database.accdb"
Dim dr As OleDbDataReader
Dim cm As New OleDbCommand
Dim cn As New OleDbConnection
Dim provider As String
Dim dataFile As String
Dim no As Integer
Dim q(no) As String
Dim quesnum As Integer
Dim answer As String
Dim selected As String
Dim score As Integer
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
no = InputBox("Input the number of questions you want. You can choose from 1 to 10.")
Label1.Hide()
Label2.Hide()
Label3.Hide()
RadioButton1.Hide()
RadioButton2.Hide()
RadioButton3.Hide()
RadioButton4.Hide()
Button1.Hide()
Button2.Hide()
Button2.Hide()
Button3.Hide()
Button4.Hide()
For i = 1 To no
question()
Next
End Sub
Private Sub question()
cn.ConnectionString = ConnectString
cn.Open()
quesnum = 1
Label1.Text = "Question " & quesnum & " of " & no
cm.CommandText = "SELECT Question, Answer1, Answer2, Answer3, CorrectAnswer FROM Question"
cm.Connection = cn
dr = cm.ExecuteReader
If dr.HasRows Then
dr.Read()
Label2.Text = dr.Item("Question")
RadioButton1.Text = dr.Item("Answer1")
RadioButton2.Text = dr.Item("Answer2")
RadioButton3.Text = dr.Item("Answer3")
RadioButton4.Text = dr.Item("CorrectAnswer")
dr.Close()
End If
cn.Close()
End Sub
Private Sub mark()
cn.ConnectionString = ConnectString
cn.Open()
cm.CommandText = "SELECT CorrectAnswer FROM Question"
cm.Connection = cn
dr = cm.ExecuteReader
If dr.HasRows Then
dr.Read()
answer = dr.Item("CorrectAnswer")
dr.Close()
End If
cn.Close()
If selected = answer Then score = score + 1
MsgBox("score is " & score)
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If RadioButton1.Checked = True Then selected = RadioButton1.Text
mark()
End Sub
Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click
Label1.Show()
Label2.Show()
Label3.Show()
RadioButton1.Show()
RadioButton2.Show()
RadioButton3.Show()
RadioButton4.Show()
Button1.Show()
Button2.Show()
Button3.Show()
Button4.Show()
Button5.Hide()
End Sub
End Class
I am also having trouble looping through the questions so that different questions and answers show when the next and back buttons are pressed.
much help appreciated, thank you!
Create a list - for example
Dim answerList As New List(Of String)
and add your query results to this - Like this
answerList.Items.Add(dr.Item("Answer1"))
answerList.Items.Add(dr.Item("Answer2"))
answerList.Items.Add(dr.Item("Answer3"))
answerList.Items.Add(dr.Item("CorrectAnswer"))
then this function to randomize the order of the list
Private Function RandomizeListOrder(answers As List(Of String)) As List(Of String)
Dim answer2 As Integer
Dim rnd As New Random
'loop though each item in the list
For answer1 As Integer = 0 To answers.Count - 1
'pick a random answer
answer2 = rnd.Next(0, answers.Count - 1)
'If answer1 and answer2 are the same then skip the rest of the code
'in the loop and go onto the next question
If answer1 = answer2 Then
Continue For
End If
'swap the questions over
Dim temp As String
temp = answers(answer1)
answers(answer1) = answers(answer2)
answers(answer2) = temp
Next
'return the list of answers
Return answers
End Function
Like this
answerList = RandomizeListOrder(answerList)
then add each element of the list to a radio button
RadioButton1.Text = answerList(0)
RadioButton2.Text = answerlist(1)
RadioButton3.Text = answerList(2)
RadioButton4.Text = answerlist(3)
Oh - and listen to Plutonix - He is wise.
Update
Hopefully when the code is added to yours, it should look like this - I think. I tested the function on my PC and it seems to work fine. If there is still an error, it may be in your code somewhere.
Imports System.Data.OleDb
Public Class Form1
Dim ConnectString As String = "Provider=Microsoft.ACE.OLEDB.12.0;" & _
" Data Source= C:\Users\Sales\Documents\Visual Studio 2010\Normalised Database.accdb"
Dim dr As OleDbDataReader
Dim cm As New OleDbCommand
Dim cn As New OleDbConnection
Dim provider As String
Dim dataFile As String
Dim no As Integer
Dim q(no) As String
Dim quesnum As Integer
Dim answer As String
Dim selected As String
Dim score As Integer
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
no = InputBox("Input the number of questions you want. You can choose from 1 to 10.")
Label1.Hide()
Label2.Hide()
Label3.Hide()
RadioButton1.Hide()
RadioButton2.Hide()
RadioButton3.Hide()
RadioButton4.Hide()
Button1.Hide()
Button2.Hide()
Button2.Hide()
Button3.Hide()
Button4.Hide()
For i = 1 To no
question()
Next
End Sub
Private Sub question()
cn.ConnectionString = ConnectString
cn.Open()
quesnum = 1
Label1.Text = "Question " & quesnum & " of " & no
cm.CommandText = "SELECT Question, Answer1, Answer2, Answer3, CorrectAnswer FROM Question"
cm.Connection = cn
dr = cm.ExecuteReader
Dim answerList As New List(Of String)
If dr.HasRows Then
dr.Read()
Label2.Text = dr.Item("Question")
answerList.Items.Add(dr.Item("Answer1"))
answerList.Items.Add(dr.Item("Answer2"))
answerList.Items.Add(dr.Item("Answer3"))
answerList.Items.Add(dr.Item("CorrectAnswer"))
answerList = RandomizeListOrder(answerList)
RadioButton1.Text = answerList(0)
RadioButton2.Text = answerlist(1)
RadioButton3.Text = answerList(2)
RadioButton4.Text = answerlist(3)
dr.Close()
End If
cn.Close()
End Sub
Private Sub mark()
cn.ConnectionString = ConnectString
cn.Open()
cm.CommandText = "SELECT CorrectAnswer FROM Question"
cm.Connection = cn
dr = cm.ExecuteReader
If dr.HasRows Then
dr.Read()
answer = dr.Item("CorrectAnswer")
dr.Close()
End If
cn.Close()
If selected = answer Then score = score + 1
MsgBox("score is " & score)
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
If RadioButton1.Checked = True Then selected = RadioButton1.Text
mark()
End Sub
Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click
Label1.Show()
Label2.Show()
Label3.Show()
RadioButton1.Show()
RadioButton2.Show()
RadioButton3.Show()
RadioButton4.Show()
Button1.Show()
Button2.Show()
Button3.Show()
Button4.Show()
Button5.Hide()
End Sub
Private Function RandomizeListOrder(answers As List(Of String)) As List(Of String)
Dim answer2 As Integer
Dim rnd As New Random
'loop though each item in the list
For answer1 As Integer = 0 To answers.Count - 1
'pick a random answer
answer2 = rnd.Next(0, answers.Count - 1)
'If answer1 and answer2 are the same then skip the rest of the code
'in the loop and go onto the next question
If answer1 = answer2 Then
Continue For
End If
'swap the questions over
Dim temp As String
temp = answers(answer1)
answers(answer1) = answers(answer2)
answers(answer2) = temp
Next
'return the list of answers
Return answers
End Function
End Class

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