So, i get the OleDBException "unspecified error" whenever the function below hits the dataAdapter.SelectCommand = dbcommand line.
I have tried adding dbcommand.connection.close() and dbcommand.connection.dispose() but neither fixed the problem.
I assume that this error would happen every time i try to connect with the DB but this is just the first function that does so in my code, so this is where the error is first occuring.
I have read online that MySQL will eventually clear out old connections after a while, if this is true, then i should just have to wait..but i dont want to keep waiting for nothing to happen.
Function GetOrders(ByVal _numberrecords As Long) As DataTable
Dim TaxConnStr As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & ConfigurationManager.AppSettings("Database")
Dim dbConnection As OleDbConnection = New OleDbConnection(TaxConnStr)
Try
'Code to get orders in call status. Sort oldest to newest
' dbConnection.Open()
Dim queryString As String
queryString = "SELECT TOP " & _numberrecords & " Orders.Control_Number, Orders.State, Orders.County, Orders.Status, Orders.ZipCode, Orders.OrderNumber, Orders.Client, Orders.Department "
queryString += "FROM Orders "
queryString += "WHERE(((Orders.Status) = 'Tax Cert Call' Or (Orders.Status) = 'Online')) "
queryString += "ORDER BY Orders.Date_Received;"
Dim dbCommand As OleDbCommand = New OleDbCommand
dbCommand.CommandText = queryString
dbCommand.Connection = dbConnection
'dbCommand.Connection.Close()
'dbCommand.Connection.Dispose()
'dbCommand.Dispose()
Dim dataAdapter As OleDbDataAdapter = New OleDbDataAdapter
dataAdapter.SelectCommand = dbCommand
Dim dataSet As DataSet = New DataSet
dataAdapter.Fill(dataSet)
If dataSet.Tables(0).Rows.Count >= 1 Then
GetOrders = dataSet.Tables(0)
End If
Catch ex As Exception
Console.WriteLine(ex.Message)
myLogger.Log(ex.Message)
Finally
dbConnection.Close()
dbConnection.Dispose()
End Try
End Function
Related
I have, for over a month, tried in vain to resolve this. I am using SQLite and trying to write a simple check to see if i can connect to the database. I found some code here that was supposed to do just that.
Public Function ConnExist(strDB) As Boolean
Dim SQLconnect As New SQLite.SQLiteConnection()
Try
Using Query As New SQLiteCommand()
SQLconnect.ConnectionString = "DataSource=" & strDB & ";Version=3;New=False;Compress=True;"
SQLconnect.Open()
With Query
.Connection = SQLconnect
.CommandText = "SELECT * FROM tbltest"
End With
Query.ExecuteNonQuery()
SQLconnect.Close()
End Using
'SQLconnect.ConnectionString = "Data Source=" & strDB & ";Version=3;New=False"
'SQLconnect.Open()
'SQLconnect.Close()
Catch ex As Exception
MsgBox(ex.Message)
'Return False
End Try
Return True
End Function
I know the database is at the location specified. On the SQLconnect.Open() part it errors out and tells me datasource cannot be empty. I opened the database using DB Browser and it is not corrupt. What am I doing wrong?
This is how I build my connection string for SQLite.
Dim constr As String = "Data Source=""" & FullFilePath & """;Pooling=true;FailIfMissing=false"
Think you are just missing the Double Quotes around the path.
Public Function ConnExist(strDB) As Boolean
Dim cs As String
Dim cnn As New SQLiteConnection
Dim cmd As New SQLiteCommand
cs = "Data Source=" & strDB & ";Version=3;New=False;"
If (IO.File.Exists(strDB)) Then
cnn = New SQLiteConnection(cs)
Try
cnn.Open()
cmd = cnn.CreateCommand()
cmd.CommandText = "SELECT * FROM tblSettings"
cmd.ExecuteNonQuery()
cnn.Close()
cmd.Dispose()
cnn.Dispose()
Catch ex As Exception
Return False
Exit Function
End Try
Else
Return False
Exit Function
End If
Return True
End Function
This is my code, I m getting error "There is no row at position 0."
Sub loadservicetype()
Dim str As String = "SELECT servicename FROM tbl_activity WHERE activity= '" & CmbActivity.Text & "' "
Dim dt As New DataTable
Dim sdr As New SqlDataAdapter(str, connection)
sdr.Fill(dt)
TxtServiceType.Text = dt.Rows(0)("servicename").ToString
End Sub
First thing is Always Use SQL Parameter to AVOID SQL injection
Like this
Dim commandText As String = "SELECT servicename FROM tbl_activity WHERE activity=#ID"
Using connection As New SqlConnection(connectionString)
Dim command As New SqlCommand(commandText, connection)
command.Parameters.Add("#ID", SqlDbType.Int).Value = ID
Try
connection.Open()
Dim rowsAffected As String = command.ExecuteNonQuery()
Catch ex As Exception
throw
End Try
End Using
MSDN SOURCE
Your DataTable is Doesn't Return any rows which You Are Trying to Access
If dt IsNot Nothing Then
If dt.Row.Count>0 Then
TxtServiceType.Text = dt.Rows(0)("servicename").ToString
End If
End If
Guy's Cant seem to find my error in VB.Net ! my codes are all right ! but the function still won't save on the database cause of Syntax error in my Insert into statement ! Please help me ! :D!
This is my Code!:D!
Dim Transaction As OleDb.OleDbTransaction = Nothing
Dim Connection As OleDb.OleDbConnection = Nothing
Try
Connection = New OleDb.OleDbConnection(My.Settings.POS_CanteenConnectionString)
Connection.Open()
Transaction = Connection.BeginTransaction
Dim SQL As String = "Insert into Recipt (ReciptDate,ReciptTotal)Values(:0,:1)"
Dim CMD1 As New OleDb.OleDbCommand
CMD1.Connection = Connection
CMD1.Transaction = Transaction
CMD1.CommandText = SQL
CMD1.Parameters.AddWithValue(":0", Now.Date)
CMD1.Parameters.AddWithValue(":1", TextBox4.Text)
CMD1.ExecuteNonQuery()
CMD1.Dispose()
SQL = "Select Max(ReciptID) As MAXID from Recipt"
Dim CMD2 As New OleDb.OleDbCommand
CMD2.Connection = Connection
CMD2.Transaction = Transaction
CMD2.CommandText = SQL
Dim ReciptID As Long = CMD2.ExecuteScalar()
CMD2.Dispose()
Dim I As Integer
For I = 0 To DGV3.Rows.Count - 1
Dim BarCode As String = DGV3.Rows(I).Cells(0).Value
Dim BuyPrice As Decimal = DGV3.Rows(I).Cells(2).Value
Dim SellPrice As Decimal = DGV3.Rows(I).Cells(3).Value
Dim ItemCount As Integer = DGV3.Rows(I).Cells(4).Value
Dim CMD3 As New OleDb.OleDbCommand
SQL = "Insert to ReciptDetails" & _
"(ReciptID,BarCode,ItemCount,ItemBuyPrice,ItemSellPrice)" & _
"Values" & _
"(:0 ,:1 ,:2 ,:3 ,:4 )"
CMD3.Connection = Connection
CMD3.Transaction = Transaction
CMD3.CommandText = SQL
CMD3.Parameters.AddWithValue(":0", ReciptID)
CMD3.Parameters.AddWithValue(":1", BarCode)
CMD3.Parameters.AddWithValue(":2", BuyPrice)
CMD3.Parameters.AddWithValue(":3", ItemCount)
CMD3.Parameters.AddWithValue(":4", SellPrice)
CMD3.ExecuteNonQuery()
CMD3.Dispose()
Next
Transaction.Commit()
Transaction.Dispose()
Connection.Close()
Connection.Dispose()
DGV3.Rows.Clear()
TextBox4.Text = ""
Catch ex As Exception
If Transaction IsNot Nothing Then
Transaction.Rollback()
End If
If Connection IsNot Nothing Then
If Connection.State = ConnectionState.Open Then
Connection.Close()
End If
End If
MsgBox(ex.Message, MsgBoxStyle.Critical Or MsgBoxStyle.OkOnly, "ERROR")
End Try
Firstly, I don't think sp parameters are called by : prefix, you should use # instead. you'll therefore need to replace the .AddWithValue (everywhere) by;
CMD1.Parameters.AddWithValue("#0", Now.Date)
CMD1.Parameters.AddWithValue("#1", TextBox4.Text)
Secondly, I think the Insert syntax isn't right, you've place TO instead of INTO and space missing. Try this;
SQL = "Insert into ReciptDetails " & _
"(ReciptID, BarCode, ItemCount, ItemBuyPrice, ItemSellPrice)" & _
" Values (#0, #1, #2, #3, #4)"
So, i get the OleDBException "unspecified error" whenever the function below hits the dataAdapter.Fill(dataset) line.
I have tried adding dbcommand.connection.close() and dbcommand.connection.dispose() but neither fixed the problem.
I assume that this error would happen every time i try to connect with the DB but this is just the first function that does so in my code, so this is where the error is first occuring.
I have read online that MySQL will eventually clear out old connections after a while, if this is true, then i should just have to wait..but i dont want to keep waiting for nothing to happen.
Function GetOrders(ByVal _numberrecords As Long) As DataTable
Dim TaxConnStr As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & ConfigurationManager.AppSettings("Database")
Dim dbConnection As OleDbConnection = New OleDbConnection(TaxConnStr)
Try
'Code to get orders in call status. Sort oldest to newest
' dbConnection.Open()
Dim queryString As String
queryString = "SELECT TOP " & _numberrecords & " Orders.Control_Number, Orders.State, Orders.County, Orders.Status, Orders.ZipCode, Orders.OrderNumber, Orders.Client, Orders.Department "
queryString += "FROM Orders "
queryString += "WHERE(((Orders.Status) = 'Tax Cert Call' Or (Orders.Status) = 'Online')) "
queryString += "ORDER BY Orders.Date_Received;"
Dim dbCommand As OleDbCommand = New OleDbCommand
dbCommand.CommandText = queryString
dbCommand.Connection = dbConnection
'dbCommand.Connection.Close()
'dbCommand.Connection.Dispose()
'dbCommand.Dispose()
Dim dataAdapter As OleDbDataAdapter = New OleDbDataAdapter
dataAdapter.SelectCommand = dbCommand
Dim dataSet As DataSet = New DataSet
dataAdapter.Fill(dataSet)
If dataSet.Tables(0).Rows.Count >= 1 Then
GetOrders = dataSet.Tables(0)
End If
Catch ex As Exception
Console.WriteLine(ex.Message)
myLogger.Log(ex.Message)
Finally
dbConnection.Close()
dbConnection.Dispose()
End Try
End Function
Found the problem. My Access Database was corrupted. I just remade the database and it all worked like gravy.
I am trying to do an update query from a winform with two variables without using a dataset.
I assign both of my variable and then run the query but it keeps giving the error that zcomp is not a valid column name. Which of course is true but I tell it which column before I say = zcomp. Below is my code that is running the query.
Dim zamnt As Integer = WopartsDataGridView.Rows(e.RowIndex).Cells(e.ColumnIndex).Value
Dim zcomp As Integer = gridRow.Cells(0).Value
Dim con As New SqlConnection
Dim cmd As New SqlCommand
Try
con.ConnectionString = "Data Source=MNT-MGR-2\SQLEX;Initial Catalog=MT;Integrated Security=True"
con.Open()
cmd.Connection = con
cmd.CommandText = "UPDATE dbo.sparts SET [dbo.sparts.QtyonHand] = [dbo.sparts.QtyonHand] - zamnt WHERE [ComponentID] = zcomp"
cmd.ExecuteNonQuery()
Catch ex As Exception
MessageBox.Show("Error while updating record on table..." & ex.Message, "Update Records")
Finally
con.Close()
gridRow.Cells(4).Value = "Yes"
End Try
I have tried it several different ways. It works just fine if I take out the zamnt and zcomp and put the actual number values that are in the variables. Please help I've been searching all day for a way to use the variables with this update query.
Thanks,
Stacy
You are probably looking for how to use parameters in ADO.NET. For your example, it can look like this:
cmd.Parameters.Add("#zamnt", zamnt);
cmd.Parameters.Add("#zcomp", zcomp);
Put these two lines anywhere before ExecuteNonQuery.
Because parameters need a # prefix, you would also need to change your query to say #zamnt instead of just zamnt, and same for zcomp:
cmd.CommandText = "UPDATE dbo.sparts SET [dbo.sparts.QtyonHand] = [dbo.sparts.QtyonHand] - #zamnt WHERE [ComponentID] = #zcomp"
In addition to using parameters, the "Using" statement closes the connection and disposes resources:
Dim zamnt As Integer = WopartsDataGridView.Rows(e.RowIndex).Cells(e.ColumnIndex).Value
Dim zcomp As Integer = gridRow.Cells(0).Value
Try
Using con As New SqlConnection("Data Source=MNT-MGR-2\SQLEX;Initial Catalog=MT;Integrated Security=True")
con.Open()
Using cmd As New SqlCommand
cmd.CommandText = "UPDATE dbo.sparts SET [dbo.sparts.QtyonHand] = [dbo.sparts.QtyonHand] - #zamnt WHERE [ComponentID] = #zcomp"
cmd.Parameters.AddWithValue("#zamt", zamnt)
cmd.Parameters.AddWithValue("#zcomp", zcomp)
cmd.ExecuteNonQuery()
End Using
End Using
Catch ex As Exception
MessageBox.Show("Error while updating record on table..." & ex.Message, "Update Records")
Finally
con.Close()
gridRow.Cells(4).Value = "Yes"
End Try
have u tried this?
Dim zamnt As Integer = WopartsDataGridView.Rows(e.RowIndex).Cells(e.ColumnIndex).Value
Dim zcomp As Integer = gridRow.Cells(0).Value
Dim con As New SqlConnection
Dim cmd As New SqlCommand
Try
con.ConnectionString = "Data Source=MNT-MGR-2\SQLEX;Initial Catalog=MT;Integrated Security=True"
con.Open()
cmd.Connection = con
cmd.CommandText = "UPDATE dbo.sparts SET [dbo.sparts.QtyonHand] = [dbo.sparts.QtyonHand] -" + zamnt + " WHERE [ComponentID] =" + zcomp
cmd.ExecuteNonQuery()
Catch ex As Exception
MessageBox.Show("Error while updating record on table..." & ex.Message, "Update Records")
Finally
con.Close()
gridRow.Cells(4).Value = "Yes"
End Try