I have a database named PriceTesting ( using Microsoft Access 2007 ) that contains a table named tbl_dress with columns:
Dress_ID, Dress_Name, Dress_Price
In the form, I have created a combobox and a text box.
So far I've succeeded binding the combobox with Dress_Name data using this code :-
Private Sub FillCombo()
Try
Dim fillcon As New OleDb.OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\annonymous\Documents\Visual Studio 2012\Projects\DressTest\DressTest\db\PriceTesting.accdb")
Dim query As String = ("SELECT Dress_Name FROM tbl_dress")
Dim da As New OleDb.OleDbDataAdapter(query, fillcon)
Dim ds As New DataSet
da.Fill(ds)
ComboBox1.ValueMember = "Dress_Name"
ComboBox1.DataSource = ds.Tables(0)
ComboBox1.SelectedIndex = 0
Catch ex As Exception
MsgBox("ERROR : " & ex.Message.ToString)
End Try
End Sub
and it works... everytime the form loads, the combobox contains the data from Dress_Name column.
Now I want the texbox.text = Dress_Price WHERE Dress_Name = combox.selecteditem
any idea how to do that?
what I have in mind is only this : -
Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
query = " SELECT Dress_Price FROM tbl_dress WHERE Dress_Name = ' " & Combobox1.Text & " ' "
Textbox1.text = query
End Sub
TRY THIS and be sure to add Dress_Price"in your query
Private Sub FillCombo()
Try
Dim fillcon As New OleDb.OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\annonymous\Documents\Visual Studio 2012\Projects\DressTest\DressTest\db\PriceTesting.accdb")
Dim query As String = ("SELECT Dress_Name, Dress_Price FROM tbl_dress")
Dim da As New OleDb.OleDbDataAdapter(query, fillcon)
Dim ds As New DataSet
da.Fill(ds)
ComboBox1.ValueMember = "Dress_Name"
ComboBox1.DataSource = ds.Tables(0)
ComboBox1.SelectedIndex = 0
texbox.DataBindings.Clear()
texbox.DataBindings.Add("Text", ds.Tables(0), "Dress_Price")
Catch ex As Exception
MsgBox("ERROR : " & ex.Message.ToString)
End Try
End Sub
OR just change the code in your idea like this and be sure to add Dress_Price"in your query
Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
dim dt as DataTable = Combobox1.DataSource
dim dr as DataRow = dt.Rows(Combobox1.SelectedIndex)
Textbox1.text = iif(dr.isNull("Dress_Price"), "", dr.isNull("Dress_Price").Tostring)
End Sub
Dim fillcon As New OleDb.OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\annonymous\Documents\Visual Studio 2012\Projects\DressTest\DressTest\db\PriceTesting.accdb")
Dim query As String = " SELECT Dress_Price FROM tbl_dress WHERE Dress_Name = ' " & Combobox1.Text & "'"
Dim da As New OleDb.OleDbDataAdapter(query, fillcon)
Dim dt As New DataTable
da.Fill(dt)
Textbox1.text = dt.rows(0).item(0)
Search for parameters to avoid sql injection. Also try to improve the query and use the ID instead of the dress_name
Related
I'm making a search bar using SELECT query and I want to transfer the results to a DataGridView. But I always get an empty DataGridView.
Nothing is wrong with the query, I already tried to input it manually in access. What am I doing wrong in the code? Here it is:
Using conn = New OleDbConnection(connstring)
Try
Dim Sql As String = "SELECT * FROM Products WHERE [Product Name] LIKE '" & txtSearchProduct.Text & "*'"
Dim da As New OleDbDataAdapter(Sql, conn)
Dim ds As New DataSet
da.Fill(ds)
DataGridView2.DataSource = ds.Tables(0)
Catch ex As Exception
MsgBox(ex.ToString, MsgBoxStyle.OkOnly Or MsgBoxStyle.Exclamation, "Error")
End Try
End Using
The issue is as I stated in the comment. ADO.Net uses the % for the like to maintain consistency with most major Sql engines. But I would like to point out that your query is unsafe and subject to SQL injection so I have included an example of your code using a parameter to pass user input to the command.
Also note that the OleDbDataAdapter can be declared in a Using statement the same way you did with the OleDbConnection Note that you may however have to widen the scope of the dataset (ds) if you plan on doing other things with it.
Using conn As OleDbConnection = New OleDbConnection(connstring)
Try
Dim Sql As String = "SELECT * FROM Products WHERE [Product Name] LIKE #Product"
Using da As OleDbDataAdapter = New OleDbDataAdapter(Sql, conn)
da.SelectCommand.Parameters.Add("#Product", OleDbType.Varchar).Value = txtSearchProduct.Text & "%"
Dim ds As New DataSet
da.Fill(ds)
DataGridView2.DataSource = ds.Tables(0)
End Using
Catch ex As Exception
MsgBox(ex.ToString, MsgBoxStyle.OkOnly Or MsgBoxStyle.Exclamation, "Error")
End Try
End Using
Like Charles has mentioned its always better to use parameters. My answer is a bit different whereas it uses a reader and not an adapter, and a datatable and not an entire dataset. An adapter should only be used if you intend to write back to the table, or typical scenarios include binding procedures. A DataSet is typically used when you have multiple tables and have a need to relate them. Also note, you most likely want a preceding % in your parameter if you want to match the string regardless of the position in the search column.
Try
Using conn = New OleDbConnection("YourConnString")
conn.Open()
Dim Cmd As New OleDbCommand("SELECT * FROM Products WHERE [Product Name] LIKE #Product", conn)
Cmd.Parameters.AddWithValue("#Product", "'%" & txtSearchProduct.Text & "%'")
Dim ProductsRDR As OleDbDataReader = Cmd.ExecuteReader
Dim DTable As New DataTable With {.TableName = "Products"}
DTable.Load(ProductsRDR)
DataGridView1.DataSource = DTable
conn.Close()
End Using
Catch ex As Exception
MsgBox(ex.ToString, MsgBoxStyle.OkOnly Or MsgBoxStyle.Exclamation, "Error")
End Try
All you have to do is replacing the * sign with % in your Sql string, just like this:
This is your wrong Sql string:
Dim Sql As String = "SELECT * FROM Products WHERE [Product Name] LIKE '" & txtSearchProduct.Text & "*'"
Change it to this:
Dim Sql As String = "SELECT * FROM Products WHERE [Product Name] LIKE '" & txtSearchProduct.Text & "%'"
This should cover most of the common scenarios out there.
Imports System.Data.SqlClient
Public Class Form1
Dim sCommand As SqlCommand
Dim sAdapter As SqlDataAdapter
Dim sBuilder As SqlCommandBuilder
Dim sDs As DataSet
Dim sTable As DataTable
Private Sub load_btn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles load_btn.Click
Dim connectionString As String = "Data Source=.;Initial Catalog=pubs;Integrated Security=True"
Dim sql As String = "SELECT * FROM Stores"
Dim connection As New SqlConnection(connectionString)
connection.Open()
sCommand = New SqlCommand(sql, connection)
sAdapter = New SqlDataAdapter(sCommand)
sBuilder = New SqlCommandBuilder(sAdapter)
sDs = New DataSet()
sAdapter.Fill(sDs, "Stores")
sTable = sDs.Tables("Stores")
connection.Close()
DataGridView1.DataSource = sDs.Tables("Stores")
DataGridView1.ReadOnly = True
save_btn.Enabled = False
DataGridView1.SelectionMode = DataGridViewSelectionMode.FullRowSelect
End Sub
Private Sub new_btn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles new_btn.Click
DataGridView1.[ReadOnly] = False
save_btn.Enabled = True
new_btn.Enabled = False
delete_btn.Enabled = False
End Sub
Private Sub delete_btn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles delete_btn.Click
If MessageBox.Show("Do you want to delete this row ?", "Delete", MessageBoxButtons.YesNo) = DialogResult.Yes Then
DataGridView1.Rows.RemoveAt(DataGridView1.SelectedRows(0).Index)
sAdapter.Update(sTable)
End If
End Sub
Private Sub save_btn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles save_btn.Click
sAdapter.Update(sTable)
DataGridView1.[ReadOnly] = True
save_btn.Enabled = False
new_btn.Enabled = True
delete_btn.Enabled = True
End Sub
End Class
I am trying to refresh my datagridview after delete something from database. The code that I am actually using on my delete button is
Private Sub cmdDelete_Click(sender As Object, e As EventArgs) Handles cmdDelete.Click
If txtDelete.Text <> "" Then
If MsgBox("Deseja apagar o ficheiro " & txtDelete.Text & "?", MsgBoxStyle.YesNo) Then
SQL.DataDelete("DELETE FROM infofile WHERE Filename='" & txtDelete.Text & "' ")
End If
Else
MsgBox("Por favor introduza um ficheiro a apagar!")
End If
RefreshDGV()
End Sub
And I've created a Sub method
Sub RefreshDGV()
Dim str1 As String = "SELECT * FROM infofile"
DataGridView1.DataSource = SQLDataSet.Tables(0)
End Sub
This is not working...
Try this:
Dim strSql As String = "SELECT * FROM infofile"
Dim dtb As New DataTable
Using cnn As New SqlConnection(connectionString)
cnn.Open()
Using dad As New SqlDataAdapter(strSql, cnn)
dad.Fill(dtb)
End Using
cnn.Close()
DataGridView1.DataSource = dtb
End Using
I'm trying to refill my DataGridView after a filter selection in a combobox.
Here is my code where I try...at this moment the code is clearing the DataGridview and just fill only on row with only 1 cell..KlantID = 7
Any idea?
Private Sub ComboBox1_SelectionChangeCommitted(sender As Object, e As EventArgs) Handles ComboBox1.SelectionChangeCommitted
klantid = ComboBox1.SelectedValue
Dim myConnection As OleDbConnection
Dim DBpath As String = "C:\Facturatie\CharelIjs.accdb"
Dim sConnectionString As String = "Provider=Microsoft.ACE.OLEDB.12.0; Data Source=" & DBpath & ";Persist Security Info=True"
myConnection = New OleDbConnection(sConnectionString)
myConnection.Open()
Dim SQLstr As String
SQLstr = "SELECT * FROM tblKlant WHERE KlantID = #klantid"
Dim cmd As New OleDbCommand(SQLstr, myConnection)
Dim da As New OleDbDataAdapter(cmd)
Dim ds As New DataSet()
cmd.Parameters.Add("#klantid", OleDbType.VarChar)
cmd.Parameters(0).Value = klantid
Try
da.Fill(ds, "tblKlant")
cmd.ExecuteNonQuery()
Catch ex As Exception
MsgBox("Can't load Web page" & vbCrLf & ex.Message)
Return
End Try
DataGridView1.DataSource = ds
DataGridView1.DataMember = "tblKlant"
DataGridView1.Refresh()
End Sub
Why are you populating records on every combobox_SelectionChange event execution. Try to filter your data only instead of query execution.
And, better to use SelectedValueChanged event instead of SelectionChange.
Private Sub form_Load(sender As Object, e As EventArgs) Handles Me.Load
//Fill your data here with DataView
Dim myConnection As OleDbConnection
Dim DBpath As String = "C:\Facturatie\CharelIjs.accdb"
Dim sConnectionString As String = "Provider=Microsoft.ACE.OLEDB.12.0; Data Source=" & DBpath & ";Persist Security Info=True"
myConnection = New OleDbConnection(sConnectionString)
myConnection.Open()
Dim cmd As New OleDbCommand("SELECT * FROM tblKlant", myConnection)
Dim da As New OleDbDataAdapter(cmd)
Dim dt As New DataTable() 'Dont use dataset if your are not relating more than one tables
cmd.Parameters.Add("#klantid", OleDbType.VarChar)
cmd.Parameters(0).Value = klantid
Try
da.Fill(dt)
dt.TableName = "tblKlant"
cmd.ExecuteNonQuery()
DataGridView1.DataSource = dt.DefaultView
DataGridView1.DataMember = "tblKlant"
Catch ex As Exception
MsgBox("Can't load Web page" & vbCrLf & ex.Message)
Return
End Try
End Sub
Private Sub combobox_SelectedValueChanged(sender As Object, e As EventArgs) Handles combobox.SelectedValueChanged
IF combobox.SelectedValue IsNot Nothing Then
Dim dv As DataView = DirectCast(DataGridView1.DataSource, DataView)
dv.RowFilter = "KlantID=" + combobox.SelectedValue.ToString()
Else
dv.RowFilter = vbNullString
End IF
End Sub
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()
.....
I have a form , which have 1 combobox and 1 textbox.
and a table named tbl_dress which have columns as Dress_ID, Dress_Name, Dress_Price..
the combobox shows the Dress_Name and the code works..
Code for the combobox :-
Private Sub FillCombo()
Try
Dim fillcon As New OleDb.OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\annonymous\Documents\Visual Studio 2012\Projects\DressTest\DressTest\db\PriceTesting.accdb")
Dim query As String = ("SELECT Dress_Name FROM tbl_dress")
Dim da As New OleDb.OleDbDataAdapter(query, fillcon)
Dim ds As New DataSet
da.Fill(ds)
ComboBox1.ValueMember = "Dress_Name"
ComboBox1.DataSource = ds.Tables(0)
ComboBox1.SelectedIndex = 0
Catch ex As Exception
MsgBox("ERROR : " & ex.Message.ToString)
End Try
End Sub
and this is the code when my form is loaded :-
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Try
Dim con As New OleDb.OleDbConnection
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()
FillCombo() ' Display data from tbl_order on form load
con.Close()
Catch ex As Exception
MessageBox.Show(ex.ToString)
End Try
End Sub
so the question is , how do i get the Dress_Price , determined by the Dress_Name chosen on the combobox.
i have tried the following code , but i have errors.
Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
Try
Dim fillcon As New OleDb.OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\annonymous\Documents\Visual Studio 2012\Projects\DressTest\DressTest\db\PriceTesting.accdb")
fillcon.Open()
Dim query As String = ("SELECT Dress_Price FROM tbl_dress WHERE Dress_Name = ' " & ComboBox1.SelectedValue.ToString & " ' ")
Dim cmd As New OleDb.OleDbCommand(query, fillcon)
cmd.CommandText = query
TextBox1.Text = cmd.ExecuteScalar().ToString()
fillcon.Close()
Catch ex As Exception
MessageBox.Show(ex.ToString)
End Try
End Sub
so where did i go wrong and what should i do? new to vb.net
Try this line on execution
TextBox1.Text= Convert.ToInt32(cmd.ExecuteScalar()).ToString()
My question was whether ur getting the desired value at that point
can you put stopper near the below method and see the return value
Dim query As String = ("SELECT Dress_Price FROM tbl_dress WHERE Dress_Name = ' " & ComboBox1.SelectedValue.ToString & " ' ")
try to hard code the dress name and check. Also try Select Top 1
Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
Try
Dim fillcon As New OleDb.OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\annonymous\Documents\Visual Studio 2012\Projects\DressTest\DressTest\db\PriceTesting.accdb")
fillcon.Open()
Dim query As String = ("SELECT Dress_Price FROM tbl_dress WHERE Dress_Name = ' " & ComboBox1.Text & " ' ")
Dim cmd As New OleDb.OleDbCommand(query, fillcon)
cmd.CommandText = query
TextBox1.Text = cmd.ExecuteScalar().ToString()
fillcon.Close()
Catch ex As Exception
MessageBox.Show(ex.ToString)
End Try
End Sub