Dim con As New SqlConnection
Dim cmd As New SqlCommand
Dim str As String
Dim dr As SqlDataReader
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
str = "select * from llr where llrno='" & TextBox1.Text & "'"
cmd = New SqlCommand(str, con)
con.Open()
dr = cmd.ExecuteReader()
If dr.HasRows Then
dr.Read()
Dim img As Byte() = DirectCast(dr("img"), Byte())
Dim ms As New MemoryStream(img)
PictureBox1.Image = Image.FromStream(ms)
End If
dr.Close()
cmd.Dispose()
con.Close()
End Sub
I think the issue may be with the previous line, try changing to this:
Dim img As Byte() = dr("img")
and see if you get the same error.
Related
I have a form with retrieved data form ms access database. While updating using the adapter update statement, it shows Syntax error.
The following are the connection code in form load event and update button click event.
could you please let me know whats wrong in this?
Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
Dim strConn As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=D:\DESKTOP\VBATESTING\ADPE Project\Project Tables\ADPE_Table.accdb"
inc = 0
Dim Con As New OleDbConnection()
Dim Cmd As New OleDbCommand
Dim SQL As String = "SELECT * FROM Heidelberg"
Con.ConnectionString = strConn
Try
Con.Open()
Catch ex As Exception
MsgBox(ex.Message)
End Try
Cmd = New OleDbCommand(SQL, Con)
Adapter.SelectCommand = New OleDbCommand(SQL, Con)
ds = New DataSet
Adapter.Fill(ds, "testing")
MaxRows = ds.Tables("testing").Rows.Count
Label1.Text = "Total Records :" & MaxRows
NavigateRecords()
End Sub
Private Sub UpdateButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles UpdateButton.Click
Dim cb As New OleDb.OleDbCommandBuilder(Adapter)
ds.Tables("testing").Rows(inc).Item(5) = TextBox1.Text
ds.Tables("testing").Rows(inc).Item(2) = TextBox2.Text
ds.Tables("testing").Rows(inc).Item(3) = TextBox3.Text
ds.Tables("testing").Rows(inc).Item(4) = TextBox4.Text
Try
Adapter.Update(ds, "testing")
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
You have way too many commands in your Form.Load.
One
Dim Cmd As New OleDbCommand
Two
Cmd = New OleDbCommand(SQL, Con)
Three
Adapter.SelectCommand = New OleDbCommand(SQL, Con)
Every time you use the New keyword, you create another command.
If you are only dealing with a single table, you don't need a DataSet. The extra object adds extra weight and complicates the code a bit.
Private inc As Integer
Private Adapter As New OleDbDataAdapter
Private MaxRows As Integer
Private dat As New DataTable
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim strConn As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=D:\DESKTOP\VBATESTING\ADPE Project\Project Tables\ADPE_Table.accdb"
inc = 0
Using Con As New OleDbConnection(strConn)
Using Cmd As New OleDbCommand("SELECT * FROM Heidelberg;", Con)
Adapter.SelectCommand = Cmd
Try
Adapter.Fill(dat)
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Using
End Using
MaxRows = dat.Rows.Count
Label1.Text = "Total Records :" & MaxRows
NavigateRecords()
End Sub
Private Sub UpdateButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles UpdateButton.Click
dat.Rows(inc).Item(5) = TextBox1.Text
dat.Rows(inc).Item(2) = TextBox2.Text
dat.Rows(inc).Item(3) = TextBox3.Text
dat.Rows(inc).Item(4) = TextBox4.Text
Dim cb As New OleDbCommandBuilder(Adapter)
'This will take care of any spaces that you have in column names.
cb.QuotePrefix = "["
cb.QuoteSuffix = "]"
Try
Adapter.Update(dat)
Catch ex As Exception
MsgBox(ex.Message)
End Try
End Sub
i have a data grid view, filled by data from database now i need to change the data and update database.
Private daVD As New OracleDataAdapter
Private cmdJV As New OracleCommandBuilder
Private dtVD As New DataTable()
Dim cmd As New OracleCommand("Select JV_CODE,JV_ACC_NAME,DEBIT,CREDIT From VOUCHER_DETAIL where VOUCHERNO =:Vno", sgcnn)
cmd.Parameters.Add("#Vno", OracleDbType.NVarchar2).Value = txtJVNo.Text.ToString.Trim
dtVD.Clear()
daVD = New OracleDataAdapter(cmd)
daVD.Fill(dtVD)
dgvAccDetail.AutoGenerateColumns = False
dgvAccDetail.DataSource = dtVD
If dtVD.Rows.Count > 0 Then
For i As Integer = 0 To dtVD.Rows.Count - 1
''Dim DataType() As String = myTableData.Rows(i).Item(1)
dgvAccDetail.Rows(i).Cells(0).Value = dtVD.Rows(i).Item("JV_CODE").ToString.Trim
dgvAccDetail.Rows(i).Cells(1).Value = dtVD.Rows(i).Item("JV_ACC_NAME").ToString.Trim
dgvAccDetail.Rows(i).Cells(2).Value = dtVD.Rows(i).Item("DEBIT").ToString.Trim
dgvAccDetail.Rows(i).Cells(3).Value = dtVD.Rows(i).Item("CREDIT").ToString.Trim
Next
End If
i tried many different ways to update the database table but not working
Try
cmdJV = New OracleCommandBuilder(da)
daJV.Update(ds, "VJ_Details")
ds.AcceptChanges()
MessageBox.Show(" The record has been updated.")
Catch ex As Exception
MsgBox(ex.Message)
End Try
I have never used Oracle, but this is how you could do it using SQL Server (there are actually several ways to push data from a DatGridView to a table in SQL Server).
Here is one option for you to try.
Imports System.Data.SqlClient
Public Class Form1
Dim connetionString As String
Dim connection As SqlConnection
Dim adapter As SqlDataAdapter
Dim cmdBuilder As SqlCommandBuilder
Dim ds As New DataSet
Dim changes As DataSet
Dim sql As String
Dim i As Int32
Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
connetionString = "Data Source=Server_Name\SQLEXPRESS;Initial Catalog=Test;Trusted_Connection=True;"
connection = New SqlConnection(connetionString)
sql = "Select * from Orders"
Try
connection.Open()
adapter = New SqlDataAdapter(Sql, connection)
adapter.Fill(ds)
DataGridView1.DataSource = ds.Tables(0)
connection.Close()
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
'NOTE: for this code to work, there must be a PK on the Table
Try
cmdBuilder = New SqlCommandBuilder(adapter)
changes = ds.GetChanges()
If changes IsNot Nothing Then
adapter.Update(changes)
End If
MsgBox("Changes Done")
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Private Sub DataGridView1_Click(sender As Object, e As EventArgs) Handles DataGridView1.Click
DataGridView1.DefaultCellStyle.SelectionBackColor = Color.Orange
End Sub
End Class
Here is one more option for you to consider.
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.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=Server_Name\SQLEXPRESS;Database=Database_Name;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
I'm just new to vb.net.. Anyway, Is there a way when I open my form the items in my database will show up automatically?
Private Sub Form3_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
list()
End Sub
Sub list()
con.Open()
cmd = New SqlCommand("SELECT * FROM Tbl", con)
rdr = cmd.ExecuteReader
ListView1.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("Brand")
itm = New ListViewItem(arr)
ListView1.Items.Add(itm)
Loop
End If
con.Close()
End Sub
You can use below code
Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
Using con As New SqlConnection(constr)
Using cmd As New SqlCommand("SELECT * FROM Tbl")
cmd.Connection = con
Using sda As New SqlDataAdapter(cmd)
Dim dt As New DataTable()
sda.Fill(dt)
End Using
End Using
End Using
Dim list As List(Of DataRow) = dt.AsEnumerable().ToList()
this code can convert direct data table to list.
I have three columns in SQL, which I want the data displayed in three textboxes by clicking an item in ComboBox.
The issue is not really displaying. I can save the data fine and display. However, one of the text fields will only show one cell and not update when a different item is selected. Hope this is making sense.
Here is the code I have for saving:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim myconnect As New SqlClient.SqlConnection
myconnect.ConnectionString = "Data Source=.\INFLOWSQL;Initial Catalog=RioDiary;Integrated Security=True"
Dim mycommand As SqlClient.SqlCommand = New SqlClient.SqlCommand()
mycommand.Connection = myconnect
mycommand.CommandText = "INSERT INTO MyDiary (Title, DiaryContent, DiaryDate) VALUES (#Title, #DiaryContent, #DiaryDate)"
myconnect.Open()
Try
mycommand.Parameters.Add("#Title", SqlDbType.VarChar).Value = TextBox1.Text
mycommand.Parameters.Add("#DiaryContent", SqlDbType.VarChar).Value = TextBox2.Text
mycommand.Parameters.Add("#DiaryDate", SqlDbType.VarChar).Value = TextBox3.Text
mycommand.ExecuteNonQuery()
MsgBox("Success")
Catch ex As System.Data.SqlClient.SqlException
And here is the code for displaying in form1:
Imports System.Data.SqlClient
Public Class Form1
Dim con As New SqlConnection
Dim ds As New DataSet
Dim da As New SqlDataAdapter
Dim sql As String
Dim inc As Integer
Dim MaxRows As Integer
Dim max As String
Dim dt As New DataTable
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'RioDiaryDataSet5.MyDiary' table. You can move, or remove it, as needed.
Me.MyDiaryTableAdapter.Fill(Me.RioDiaryDataSet5.MyDiary)
Dim con As New SqlConnection(" Data Source=.\INFLOWSQL;Initial Catalog=RioDiary;Integrated Security=True")
Dim cmd As New SqlCommand("Select Title,DiaryContent,DiaryDate FROM MyDiary ")
Dim da As New SqlDataAdapter
da.SelectCommand = cmd
cmd.Connection = con
da.Fill(ds, "MyDiary")
con.Open()
ComboBox1.DataSource = ds.Tables(0)
ComboBox1.DisplayMember = "Title'"
ComboBox1.ValueMember = "DiaryContent"
End Sub
Private Sub NewEntryToolStripMenuItem_Click(sender As Object, e As EventArgs) Handles NewEntryToolStripMenuItem.Click
AddEntry.Show()
End Sub
Private Sub ComboBox1_SelectedIndexChanged(sender As Object, e As EventArgs) Handles ComboBox1.SelectedIndexChanged
If (Not Me.ComboBox1.SelectedValue Is Nothing) Then
Me.TextBox2.Text = ComboBox1.Text
Me.TextBox3.Text = ComboBox1.SelectedValue.ToString
End If
End Sub
Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
If dt.Rows.Count > 0 Then
TextBox1.Text = dt.Rows(0)("DiaryDate").ToString() 'Where ColumnName is the Field from the DB that you want to display
End If
End Sub
End Class
As you can see from the code, I want to display Title and DiaryContent in two separate textboxes by clicking on Title in the Combobox. This works fine.
The issue I have is DiaryDate only shows the first entry and does not update when selecting the Item from ComboBox.
Can anyone help?
You can try to play with ComboBox's SelectedItem property. Since ComboBox's DataSource is DataTable here, SelectedItem of ComboBox represent a row in DataTable. Given DataRow in hand, you can display value of any column of DataRow in TextBoxes :
........
If (Not Me.ComboBox1.SelectedItem Is Nothing) Then
Dim SelectedItem = TryCast(comboBox1.SelectedItem, DataRowView)
Me.TextBox1.Text = SelectedItem.Row("Title").ToString()
Me.TextBox2.Text = SelectedItem.Row("DiaryContent").ToString()
Me.TextBox3.Text = SelectedItem.Row("DiaryDate").ToString()
End If
........
Public Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim cn As New SqlClient.SqlConnection("Data Source=thee-pc;Initial Catalog=jobportal;Integrated Security=True")
Dim cmd As New SqlClient.SqlCommand
Dim tbl As New DataTable
Dim da As New SqlClient.SqlDataAdapter
Dim reader As SqlClient.SqlDataReader
Try
cn.Open()
Dim sql As String
sql = "select * from Register"
cmd = New SqlClient.SqlCommand(sql, cn)
reader = cmd.ExecuteReader
While reader.Read
Dim id = reader.Item("cid")
ComboBox1.Items.Add(id)
End While
cn.Close()
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged
Dim cn As New SqlClient.SqlConnection("Data Source=thee-pc;Initial Catalog=jobportal;Integrated Security=True")
Dim cmd As New SqlClient.SqlCommand
Dim tbl As New DataTable
Dim da As New SqlClient.SqlDataAdapter
Dim reader As SqlClient.SqlDataReader
Try
cn.Open()
Dim sql As String
sql = "select * from register where cid ='" + ComboBox1.Text + "'"
cmd = New SqlClient.SqlCommand(sql, cn)
reader = cmd.ExecuteReader
While reader.Read
TextBox1.Text = reader.Item("cname")
TextBox2.Text = reader.Item("dob")
End While
cn.Close()
Catch ex As Exception
MessageBox.Show(ex.Message)
End Try
End Sub
I want to select some data in my table and I use this code :
Public Class frmLogin
Private Sub OK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnOK.Click
Dim t As New DataTable
Dim adapter As OleDbDataAdapter = New OleDbDataAdapter()
Dim cmd As OleDbCommand
Dim reader As OleDbDataReader = Nothing
Dim tuser As String = txtUsername.Text
Dim sql As String = "SELECT * FROM dosen WHERE nip=tuser"
Try
cmd = New OleDbCommand(sql, conn)
reader = cmd.ExecuteReader()
While reader.Read
MessageBox.Show(reader.GetString(0).ToString & _
vbTab & vbTab & reader.GetString(1).ToString)
End While
Finally
If reader IsNot Nothing Then reader.Close()
End Try
End Sub
But there is an error in reader = cmd.ExecuteReader() line. Anyone can help me?
Correct the mistakes. The code should be
Dim reader As OleDbDataReader ' no need for nothing
Dim adapter As New OleDbDataAdapter()
Dim sql As String = "SELECT * FROM dosen WHERE nip='" & tuser & "'"
tuser is a variable, not the content