I am facing a primary key voilation error in the following code:
Private Sub ProductForm_Load(sender As Object, e As EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'BismillahDBDataSet.Product' table. You can move, or remove it, as needed.
Me.ProductTableAdapter.Fill(Me.BismillahDBDataSet.Product)
AddHandler ProductGrid.RowsAdded, AddressOf ProductGrid_RowsAdded
Dim ProductAdapter = New SqlDataAdapter("Select * from product", My.Settings.BismillahDBCN)
Dim ProductTable = New DataTable()
ProductAdapter.Fill(ProductTable)
ProductGrid.DataSource = ProductTable
End Sub
Private Sub ProductGrid_RowsAdded(sender As Object, e As DataGridViewRowsAddedEventArgs)
Dim RowID As Integer = ProductGrid.CurrentRow.Index
Dim ColID As Integer = ProductGrid.CurrentCell.ColumnIndex
Try
SQLText("insert into Product (ProductID, ProductName,UnitPrice,QtyInHand) values('" & ProductGrid.Item(0, RowID).Value & "','" & ProductGrid.Item(1, RowID).Value & "','" & ProductGrid.Item(2, RowID).Value & "','" & ProductGrid.Item(3, RowID).Value & "')")
Catch ex As Exception
Exit Sub
Finally
' Dim RowID As Integer = ProductGrid.CurrentRow.Index
' Dim ColID As Integer = ProductGrid.CurrentCell.ColumnIndex
Dim cn As New SqlConnection(My.Settings.BismillahDBCN)
cn.Open()
Dim cmd As New SqlCommand
cmd.Connection = cn
Dim rdr As SqlDataReader
cmd.CommandText = "Select * from Product where Productid=" & ProductGrid.Item(0, ColID).Value
rdr = cmd.ExecuteReader
rdr.Read() 'while rdr.Read()
If rdr.HasRows = True Then
MsgBox("Productid already exists!, Enter new ProductID")
'TxtInvoiceNo.Focus()
' Exit Sub
End If
End Try
End Sub
I also tried UserAddedRows event but as soon as i start typing in PRODUCTID column of the PRODUCTGRID (even 1 digit) it displays the voilation message
Please help
Related
Hello I have this problem in came upon when trying to do simple manual search in vb.net. It says System.IndexOutOfRangeException: 'Cannot find column 4.'
could anyone explain what this means i am quite new to coding and dont quite get what i could to do fix this. In the attached database i have only one table called customer with 4 columns custid, custfname, custlname and dob.
This is the code and the error occurs in the btnNext and Navigaterecords. The database was made in sqlite
Imports System.Data.SQLite
Public Class Form1
Dim inc As Integer
Dim MaxRows As Integer
Dim ConnectionString As String = "Data Source=dbRoomBookings.db"
Dim ds As New DataSet
Dim dt As New DataTable
Dim mSQL As String = "SELECT * FROM Customer"
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim con As New SQLiteConnection(ConnectionString)
Dim cmd As New SQLiteCommand(mSQL, con)
con.Open()
Dim da As New SQLiteDataAdapter(cmd)
da.Fill(ds, "customer")
dt = ds.Tables(0)
MaxRows = ds.Tables("customer").Rows.Count
con.Close()
Dim msSQL As String = "SELECT * FROM customer;"
dgvSearchResults.DataSource = display(msSQL, "customer")
End Sub
Private Sub BtnNext_Click(sender As Object, e As EventArgs) Handles btnNext.Click
If inc <> MaxRows - 1 Then
inc = inc + 1
txtCusId.Text = ds.Tables("customer").Rows(inc).Item(0)
txtFname.Text = ds.Tables("customer").Rows(inc).Item(1)
txtLname.Text = ds.Tables("customer").Rows(inc).Item(2)
cboDay.Text = ds.Tables("customer").Rows(inc).Item(3)
cboMonth.Text = ds.Tables("customer").Rows(inc).Item(4)
cboYear.Text = ds.Tables("Customer").Rows(inc).Item(5)
Else
MsgBox("no more rows")
End If
End Sub
Sub navigaterecords()
txtCusId.Text = ds.Tables("customer").Rows(inc).Item(0)
txtFname.Text = ds.Tables("customer").Rows(inc).Item(1)
txtLname.Text = ds.Tables("customer").Rows(inc).Item(2)
cboDay.Text = ds.Tables("customer").Rows(inc).Item(3)
cboMonth.Text = ds.Tables("customer").Rows(inc).Item(4)
cboYear.Text = ds.Tables("customer").Rows(inc).Item(5)
txtDbo.Text = ds.Tables("customer").Rows(inc).Item(3) & "/" & ds.Tables("customer").Rows(inc).Item(4) & "/" & ds.Tables("customer").Rows(inc).Item(5)
End Sub
Private Sub BtnPrevious_Click(sender As Object, e As EventArgs) Handles btnPrevious.Click
If inc > 0 Then
inc = inc - 1
navigaterecords()
Else
MsgBox("no more rows")
End If
End Sub
Private Sub BtnFirst_Click(sender As Object, e As EventArgs) Handles btnFirst.Click
If inc <> 0 Then
inc = 0
navigaterecords()
End If
End Sub
Private Sub BtnLast_Click(sender As Object, e As EventArgs) Handles btnLast.Click
If inc <> MaxRows - 1 Then
inc = MaxRows - 1
navigaterecords()
Else
End If
End Sub
Private Sub BtnSearch_Click(sender As Object, e As EventArgs) Handles btnSearch.Click
Dim sSQL As String
Dim newds As New DataSet
Dim newdt As New DataTable
If txtSearchFname.Text <> "" Then
sSQL = "SELECT * FROM customer WHERE custfname LIKE'" & txtSearchFname.Text & "%'"
Dim con As New SQLiteConnection(ConnectionString)
Dim cmd As New SQLiteCommand(sSQL, con)
con.Open()
Dim da As New SQLiteDataAdapter(cmd)
da.Fill(newds, "customer")
newdt = newds.Tables(0)
dgvSearchResults.DataSource = newdt
con.Close()
ElseIf txtSearchId.Text <> "" Then
sSQL = "SELECT * FROM customer WHERE custid ='" & txtSearchId.Text & "'"
Dim con As New SQLiteConnection(ConnectionString)
Dim cmd As New SQLiteCommand(sSQL, con)
con.Open()
Dim da As New SQLiteDataAdapter(cmd)
da.Fill(newds, "customer")
newdt = newds.Tables(0)
dgvSearchResults.DataSource = newdt
con.Close()
End If
End Sub
Private Sub BtnDelete_Click(sender As Object, e As EventArgs) Handles btnDelete.Click
Dim con2 As New SQLiteConnection
Dim da2 As New SQLiteDataAdapter
Dim dsql, qsql As String
Dim ds2 As New DataSet
Dim dt2 As DataTable
con2 = New SQLiteConnection(ConnectionString)
dsql = "DELETE FROM customer WHERE custid = " & txtSearchId.Text & ""
qsql = "SELECT * FROM customer"
Dim cmd As New SQLiteCommand(qsql, con2)
con2.Open()
da2.DeleteCommand = con2.CreateCommand
da2.DeleteCommand.CommandText = dsql
da2.DeleteCommand.ExecuteNonQuery()
MsgBox("Row(s) Deleted !! ")
Dim da3 As New SQLiteDataAdapter(cmd)
da3.Fill(ds2, "customer")
dt2 = ds2.Tables(0)
dgvSearchResults.DataSource = dt2
con2.Close()
End Sub
Private Sub BtnUpdate_Click(sender As Object, e As EventArgs) Handles btnUpdate.Click
Dim con3 As New SQLiteConnection
Dim da3 As New SQLiteDataAdapter
con3 = New SQLiteConnection(ConnectionString)
Dim usql As String = "UPDATE Customer SET custfname = '" & txtFname.Text & "'" & "WHERE custid =" & CInt(txtCusId.Text) & ""
con3.Open()
da3.UpdateCommand = con3.CreateCommand
da3.UpdateCommand.CommandText = usql
da3.UpdateCommand.ExecuteNonQuery()
MsgBox("Row Updated")
End Sub
Private Sub BtnAdd_Click(sender As Object, e As EventArgs) Handles btnAdd.Click
Dim isql As String = "INSERT INTO customer(custfname, custlname, dob) VALUES('" _
& txtFname.Text & "','" & txtLname.Text & "','" & cboYear.Text _
& "-" & cboMonth.Text & "-" & cboDay.Text & "');"
Dim msql As String = "SELECT * FROM customer"
add(isql)
'refresh the Data Grid
dgvSearchResults.DataSource = display(msql, "customer")
End Sub
End Class
Here is the specific documentation on IndexOutOfRangeException: https://learn.microsoft.com/en-us/dotnet/api/system.indexoutofrangeexception
For visibility, the definition is:
The exception that is thrown when an attempt is made to access an
element of an array or collection with an index that is outside its
bounds.
In your case, you are trying to get a value by passing the index of a column but the index you're passing is greater than the total number of columns.
Assuming that your table definition has the following columns: custfname, custlname, and dob, the following represents when the Exception would occur:
Get column 0, returns the value of custfname
Get column 1, returns the value of custlname
Get column 2, returns the value of dob
Get column 3, throws an IndexOutOfRangeException
The same thing would also happen if you tried to get a value at a negative index too.
You have a 4-column table which will have indexes from 0 to 3 only:
custid is column 0, custfname is column 1, custfname is column 2, and dob is column 3.
So any attempt to access ds.Tables("customer").Rows(inc).Item(4) (and (5), etc) will yield an Index out of range exception.
But you seem to know that the table only has 4 columns; why are you then attempting to access columns that you know don't exist? I'm a bit confused by that. If you're trying to split DOB into day/month/year, you'll have to manipulate the dob value from the DOB composite column, Item(3).
I am currently writing a simple stock control Visual Basic program linked to a database.
Here's what it looks like so far.
The form displays the data in a DataGrid View and I am trying to refresh my DataGridView automatically when data is changed (using SQL) in the database I am using.
After doing some research I have found that the best way to do this is by binding the data table (using BindingSource) to the DataGridView
However I am struggling to implement this, as every implementation I have tried results in a blank DataGridView and would thoroughly appreciate it if someone could assist me.
Here's the code:
Imports System.Data.OleDb
Public Class Form1
Public connectionString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=dbStock.accdb"
Public conn As New OleDb.OleDbConnection(connectionString)
Public Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Me.TblStockControlTableAdapter.Fill(Me.DbStockDataSet.tblStockControl)
For i As Integer = 1 To 5
ComboBoxQty1.Items.Add(i)
ComboBoxQty2.Items.Add(i)
Next
Dim SqlQuery As String = "Select tblStockControl.[EggType] FROM tblStockControl"
Dim da As OleDbDataAdapter = New OleDbDataAdapter(SqlQuery, conn)
Dim ds As DataSet = New DataSet
da.Fill(ds, "tblStockControl")
Dim dt As DataTable = ds.Tables("tblStockControl")
'DataGridView1.DataSource = dt
For Each row As DataRow In dt.Rows
ComboBoxAdd.Items.Add(row.Item(0))
Next
For Each row As DataRow In dt.Rows
ComboBoxTake.Items.Add(row.Item(0))
Next
End Sub
Private Sub btnAddEgg_Click(sender As Object, e As EventArgs) Handles btnAddEgg.Click
conn.Open()
Dim SqlQuery As String = "Select tblStockControl.[Quantity] FROM tblStockControl WHERE EggType = '" & ComboBoxAdd.Text & "'"
Dim da As OleDbDataAdapter = New OleDbDataAdapter(SqlQuery, conn)
Dim ds As DataSet = New DataSet
da.Fill(ds, "tblStockControl")
Dim dt As DataTable = ds.Tables("tblStockControl")
Dim qty As Integer = 0
For Each row As DataRow In dt.Rows
For Each column As DataColumn In dt.Columns
qty = row(column)
Next
Next
Dim NewQty As Integer = qty + CInt(ComboBoxQty2.Text)
UpdateAddQty(NewQty)
conn.Close()
End Sub
Function UpdateAddQty(ByRef NewQty As Integer) As Integer
Dim SqlUpdate As String = "UPDATE tblStockControl SET Quantity = '" & NewQty & "' WHERE EggType = '" & ComboBoxAdd.Text & "'"
Dim SqlCommand As New OleDbCommand
With SqlCommand
.CommandText = SqlUpdate
.Connection = conn
.ExecuteNonQuery()
End With
Return (Nothing)
End Function
Private Sub btnViewStock_Click(sender As Object, e As EventArgs) Handles btnViewStock.Click
'Add code to open Access file.
End Sub
Private Sub btnTakeEgg_Click(sender As Object, e As EventArgs) Handles btnTakeEgg.Click
conn.Open()
Dim SqlQuery As String = "Select tblStockControl.[Quantity] FROM tblStockControl WHERE EggType = '" & ComboBoxTake.Text & "'"
Dim da As OleDbDataAdapter = New OleDbDataAdapter(SqlQuery, conn)
Dim ds As DataSet = New DataSet
da.Fill(ds, "tblStockControl")
Dim dt As DataTable = ds.Tables("tblStockControl")
Dim qty As Integer = 0
For Each row As DataRow In dt.Rows
For Each column As DataColumn In dt.Columns
qty = row(column)
Next
Next
Dim NewQty As Integer = CInt(ComboBoxQty1.Text) - qty
UpdateTakeQty(NewQty)
conn.Close()
End Sub
Function UpdateTakeQty(ByRef NewQty As Integer) As Integer
Dim SqlUpdate As String = "UPDATE tblStockControl SET Quantity = '" & NewQty & "' WHERE EggType = '" & ComboBoxTake.Text & "'"
Dim SqlCommand As New OleDbCommand
With SqlCommand
.CommandText = SqlUpdate
.Connection = conn
.ExecuteNonQuery()
End With
Return (Nothing)
End Function
End Class
If you are using a DataTable , then reset the dataasource of the DataGridView.I mean you need to read data from the database again. :
'Do this every time you add/Update a data
Dim da As OleDbDataAdapter = New OleDbDataAdapter(SqlQuery, conn)
Dim ds As DataSet = New DataSet
da.Fill(ds, "tblStockControl")
Dim dt As DataTable = ds.Tables("tblStockControl")
Or you can just create a row for every data you add to your database :
'Do this every time you add a data
DataGridViewRow row = (DataGridViewRow)DataGridView1.Rows[0].Clone()
row.Cells[0].Value = "Alex"
row.Cells[1].Value = "Jordan"
DataGridView1.Rows.Add(row)
See pic
Just new to vb.net. Anyway, I don't know how I will put the value of product and price I picked in the database since it's in the list view. I tried
Dim txtValue as String
txtValue = ListView1.FocusedItem.SubItems(0).text. To get the values of the columns.
In the picture I provided, If I the put the customername and I pick her order in the listview1 it will save in my database. And it will show it my listview2. Just disregard the address.
UPDATE I think this code works but there's still error message showing up.Error message see pic
Imports System.Data.SqlClient
Imports System.IO
Public Class Form1
Dim con As SqlConnection = New SqlConnection("server=.\SQL;database=try;Trusted_Connection=TRUE")
Dim cmd As SqlCommand
Dim cmd2 As SqlCommand
Dim rdr As SqlDataReader
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
con.Open()
con.Close()
list()
list2()
End Sub
Sub list()
con.Open()
cmd = New SqlCommand("SELECT * FROM ProductTable", con)
rdr = cmd.ExecuteReader
ListView1.Items.Clear()
If rdr.HasRows Then
Do While rdr.Read()
Dim arr As String() = New String(2) {}
Dim itm As ListViewItem
arr(0) = rdr("productID")
arr(1) = rdr("product")
arr(2) = rdr("price")
itm = New ListViewItem(arr)
ListView1.Items.Add(itm)
Loop
End If
con.Close()
End Sub
Private Sub btnsave_Click(sender As Object, e As EventArgs) Handles btnsave.Click
modifyrecord("Insert into ProductOrder([name],[product],[price]) values ('" & txtname.Text & "','" & ListView1.SelectedItems(0).SubItems(1).Text & "'," & ListView1.SelectedItems(0).SubItems(2).Text & "")
End Sub
Private Sub listView1_MouseClick_1(ByVal sender As Object, ByVal e As MouseEventArgs)
End Sub
Sub list2()
con.Open()
cmd2 = New SqlCommand("SELECT * FROM ProductOrder", con)
rdr = cmd2.ExecuteReader
ListView2.Items.Clear()
If rdr.HasRows Then
Do While rdr.Read()
Dim arr As String() = New String(3) {}
Dim itm As ListViewItem
arr(0) = rdr("id")
arr(1) = rdr("name")
arr(2) = rdr("product")
arr(3) = rdr("price")
itm = New ListViewItem(arr)
ListView2.Items.Add(itm)
Loop
End If
con.Close()
End Sub
Sub modifyrecord(ByVal sql)
If txtname.Text = "" Or ListView1.SelectedItems(0).SubItems(1).Text = "" Or IsNumeric(ListView1.SelectedItems(0).SubItems(2).Text) = False Then
Else
con.Open()
cmd = New SqlCommand(sql, con)
cmd.ExecuteNonQuery()
con.Close()
list()
End If
End Sub
End Class
Try this
txtValue = ListView1.SelectedItems(0).SubItems(1).Text
txtValue1 = ListView1.SelectedItems(0).SubItems(2).Text
To get the Product and price from the list view
I assume you have the MultiSelect set to false.
Someone help me
I am working on our project and I need to check if my DB has already 20 records.
If so, then it will not accept records anymore.
I've been trying the codes below:
Public Class Form1
Dim con As New OleDb.OleDbConnection
Dim ds, ds2 As New DataSet
Dim da, da2 As OleDb.OleDbDataAdapter
Dim sql, sql1 As String
Dim int As Integer
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
End Sub
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
con.ConnectionString = "Provider=Microsoft.jet.OLEDB.4.0; data source = |datadirectory|\Database6.mdb"
con.Open()
Dim cmd As OleDb.OleDbCommand = New OleDb.OleDbCommand("SELECT * FROM Accounts WHERE Username='" & TextBox1.Text & "'", con)
Dim sdr As OleDb.OleDbDataReader = cmd.ExecuteReader
Dim cmd1 As OleDb.OleDbCommand = New OleDb.OleDbCommand("SELECT * FROM Accounts")
sql = "INSERT INTO Accounts ([Username], [Password], [FirstName], [LastName]) VALUES ('" & TextBox1.Text & "','" & TextBox2.Text & "', '" & TextBox3.Text & "','" & TextBox4.Text & "') "
sql1 = "SELECT Count([AccountID]) FROM Accounts"
cmd = New OleDb.OleDbCommand(sql, con)
cmd1 = New OleDb.OleDbCommand(sql1, con)
Convert.ToInt32(sql1)
cmd1.ExecuteScalar()
If sql1 < 20 Then
MsgBox("Cannot accept records")
ElseIf sdr.HasRows = False Then
cmd.ExecuteNonQuery()
MsgBox("Account Added")
ElseIf sdr.HasRows = True Then
MsgBox("Username is taken")
End If
con.Close()
End Sub
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
Me.Hide()
Form2.Show()
End Sub
End Class
But the convert code fires an error :
Input string was in incorrect format
But if I delete the convert code it gives me the error
Conversion from string "SELECT Count([AccountID]) FROM A" to type 'Double' is not valid."
Help me please.
TIA
I dont know VB all that well, this is from the top of my head. Your trying to convert your SQL text, which will never work. Try something like this:
dim result as object
result = cmd1.ExecuteScalar()
dim count as int
count = Convert.ToInt32(result)
If count < 20 Then
i got 2 forms... Dress_Price is for displaying the data form database ( MS Access 2007 ) another form,Edit_Dress is to edit and update the database..
the code successfully updated the data based on the changes from the form Edit_Dress.. but there is 2 problems -
the dgvCustomerDressPrice did not refreshed after updating..
there is "space" being added to the record after updated..
before update price value
Dress_Name = "Tuxedo" Dress_Price = "150"
after update price value
Dress_Name = " Tuxedo" Dress_Price = " 250"
the "space" keeps being added up everytime i update the record... so the search function cant work properly because of the space..
code on Dress_Price :-
Private Sub Dress_Price_Load(sender As Object, e As EventArgs) Handles MyBase.Load
con.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\annonymous\Documents\Visual Studio 2012\Projects\TMS Final\TMS Final\db\db_TMS.accdb"
con.Open()
dgvCustomerDressPrice()
End Sub
Private Sub dgvCustomerDressPrice()
Dim ds As New DataSet
Dim dt As New DataTable
ds.Tables.Add(dt)
Dim da As New OleDb.OleDbDataAdapter
da = New OleDb.OleDbDataAdapter("SELECT * FROM tbl_dress", con)
da.Fill(dt)
dgvDressPrice.DataSource = dt.DefaultView
dgvDressPrice.SelectionMode = DataGridViewSelectionMode.FullRowSelect
con.Close()
End Sub
Private Sub btnEditDress_Click(sender As Object, e As EventArgs) Handles btnEditDress.Click
If dgvDressPrice.Rows.Count > 0 Then ' when user click a row, any query for database will based on Order_ID
If dgvDressPrice.SelectedRows.Count > 0 Then
Dim intDressID As Integer = dgvDressPrice.SelectedRows(0).Cells("Dress_ID").Value
Try
If Not con.State = ConnectionState.Open Then
con.Open()
End If
Dim da As New OleDb.OleDbDataAdapter("SELECT * FROM tbl_dress WHERE Dress_ID =" & intDressID, con)
' the record that will be edited is based on the Customer_ID of particular row clicked
Dim dt As New DataTable
da.Fill(dt)
Edit_Dress.txtDressID.Text = intDressID
Edit_Dress.txtDressName.Text = dt.Rows(0).Item("Dress_Name")
Edit_Dress.txtDressPrice.Text = dt.Rows(0).Item("Dress_Price")
' pass the data from tbl_user into each represented field
Catch ex As Exception
MessageBox.Show("Failed to edit data ! System eror : " & ex.ToString, "Eror !", MessageBoxButtons.OK)
End Try
End If
End If
Edit_Dress.Show()
End Sub
Private Sub txtSearch_TextChanged(sender As Object, e As EventArgs) Handles txtSearch.TextChanged
If Not con.State = ConnectionState.Open Then
con.Open()
End If
Dim da As New OleDb.OleDbDataAdapter("SELECT * FROM tbl_dress WHERE Dress_Name like '" & txtSearch.Text & "%' ", con)
Dim dt As New DataTable
da.Fill(dt)
dgvCustomerDressPrice().DataSource = dt
con.Close()
End Sub
code on Edit_Dress :-
Private Sub btnUpdate_Click(sender As Object, e As EventArgs) Handles btnUpdate.Click
con = New OleDb.OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\annonymous\Documents\Visual Studio 2012\Projects\TMS Final\TMS Final\db\db_TMS.accdb")
Try
If con.State = ConnectionState.Closed Then
con.Open()
End If
Dim intDressID As Integer
intDressID = Convert.ToInt32(txtDressID.Text)
intDressID = Integer.Parse(txtDressID.Text)
Dim intDressPrice As Integer
intDressPrice = Convert.ToInt32(txtDressPrice.Text)
intDressPrice = Integer.Parse(txtDressPrice.Text)
Dim query As String = "UPDATE tbl_dress SET Dress_Name = ' " & txtDressName.Text & " ' , Dress_Price = ' " & intDressPrice & " ' WHERE Dress_ID = " & intDressID & " "
Dim cmd As New OleDb.OleDbCommand(query, con)
cmd.ExecuteNonQuery()
MessageBox.Show("Data updated !", "", MessageBoxButtons.OK, MessageBoxIcon.Information)
Dress_Price.RefreshPriceList()
con.Close()
Me.Close()
Catch ex As Exception
MessageBox.Show("Failed to save into database ! System eror : " & ex.Message, " ", MessageBoxButtons.OK, MessageBoxIcon.Error)
End Try
End Sub
Looking at your UPDATE method it is clear why you have a space added every time. You put it in the update string.
Dim query As String = "UPDATE tbl_dress SET Dress_Name = ' " & _
^ here
txtDressName.Text & " ' , Dress_Price = ' " & _
^here ^here
intDressPrice & " ' WHERE Dress_ID = " & intDressID & " "
^here
A part from the simple error that could be fixed removing the space, this is not the correct way to create an update command. You should use a parameterized query
Private Sub btnUpdate_Click(sender As Object, e As EventArgs) Handles btnUpdate.Click
con = New OleDb.OleDbConnection(.....)
Try
If con.State = ConnectionState.Closed Then
con.Open()
End If
Dim intDressID As Integer
intDressID = Convert.ToInt32(txtDressID.Text)
Dim intDressPrice As Integer
intDressPrice = Convert.ToInt32(txtDressPrice.Text)
Dim query As String = "UPDATE tbl_dress SET Dress_Name = ?, Dress_Price = ? " & _
"WHERE Dress_ID = ?"
Dim cmd As New OleDb.OleDbCommand(query, con)
cmd.Parameters.AddWithValue("#p1", txtDressName.Text)
cmd.Parameters.AddWithValue("#p2", intDressPrice)
cmd.Parameters.AddWithValue("#p3", intDressID)
cmd.ExecuteNonQuery()
.....