This is a new concept for me and I can't quite see what's causing the error
I'm attempting to populate a datagridview control from a single field in an Access database (from a combo and Text box source).
Using literals works, but not with the parameter.
Dim conn As New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & Backend & ";Persist Security Info=False;")
Dim command As New OleDbCommand("Select Year from tblTest ", conn)
Dim criteria As New List(Of String)
If Not cboYear.Text = String.Empty Then
criteria.Add("Year = #Year")
command.Parameters.AddWithValue("#Year", cboYear.Text)
End If
If criteria.Count > 0 Then
command.CommandText &= " WHERE " & String.Join(" AND ", criteria)
End If
Dim UserQuery As New OleDbDataAdapter(command.CommandText, conn)
Dim UserRet As New DataTable
UserQuery.Fill(UserRet)
With frmDGV.DataGridView2
.DataSource = UserRet
End With
frmDGV.DataGridView2.Visible = True
frmDGV.Show()
Trying to Fill the datatable shows exception 'No value given for one or more required parameters.'
The value of command.CommandText at that point is "Select Year from tblTest WHERE Year = #Year"
Your instance of OleDbDataAdapter was created using two parameters query text and connection.
Dim UserQuery As New OleDbDataAdapter(command.CommandText, conn)
In this case DataAdapter doesn't know about parameters at all.
Instead use constructor with paremeter of type OleDbCommand.
Dim UserQuery As New OleDbDataAdapter(command)
In your code instance of OleDbCommand already associated with connection
Related
I am trying to compare the values in my dictionary which contains values/quantities to a standard database containing similar values/quantities. I want to check if the value matches the database, then check if the quantity is less than the database.
I keep getting an error when I run the code on the "Using myreader" line, with the following: System.Data.OleDb.OleDbException: 'IErrorInfo.GetDescription failed with E_FAIL(0x80004005).' This is my first time using OleDBDatareader so perhaps I am doing something incorrectly. Is this not allowed, I assumed comparing a list a values in a dictionary should be possible.
Dim myconnection As OleDbConnection
Dim constring As String = "Provider=Microsoft.ACE.OLEDB.12.0; Data Source=C:\UsersTables.accdb; Persist Security Info=False"
myconnection = New OleDbConnection(constring)
myconnection.Open()
Dim keepSell As String
For Each KeyPair In colSums
Dim sqlQry As String
sqlQry = "SELECT Part,Quantity FROM PartsList WHERE Item = '" & keyPair.Key & "'AND Size= '" & keyPair.Value & "'"
Dim cmd As New OleDbCommand(sqlQry, myconnection)
Using myreader As OleDbDataReader = cmd.ExecuteReader()
If myreader.Read() Then
keepSell = "Keep"
Else
keepSell= "Sell"
End If
'myreader.Close()
End Using
DataGridView1.Rows.Add(KeyPair.Key, KeyPair.Value, keepSell)
Next
Im trying to edit items after inserting to access by clicking the save button? How can i save the edits done in datagridview rows to access?
Already tried the update query
For each loop
vb.net
Private Sub BunifuFlatButton1_Click(sender As Object, e As EventArgs) Handles BunifuFlatButton1.Click
Dim constring As String = ("Provider=Microsoft.ACE.OLEDB.12.0;Data Source= C:\Users\PU-IMO\Desktop\BlueWavesIS - Copy\BlueWavesIS\BlueWavesIS.accdb")
Dim conn As New OleDbConnection(constring)
For Each row As DataGridViewRow In DataGridView1.Rows
Using con As New OleDbConnection(constring)
'nettxt.Text = (grosstxt.Text * perdistxt.Text / 100) - (dislctxt.Text + disusd.Text + distax.Text)
Dim cmd As New OleDbCommand("Update PurchaseInvoice set [Itemnum] = #ItemNum, [Itemname]= #ItemName, [Itemqty]= #ItemQty, [Itemprice] = #ItemPrice, [discount] =#discount, [subtotal] = #subtotal,[Preference] = " & preftxt.Text & ", [Suppnum] = " & pnumtxt.Text & ", [UniqueID] = " & pautotxt.Text & " Where [UniqueID] = " & pautotxt.Text & "", con)
cmd.Parameters.AddWithValue("#ItemID", row.Cells("ItemID").Value)
cmd.Parameters.AddWithValue("#ItemName", row.Cells("ItemName").Value)
cmd.Parameters.AddWithValue("#ItemQty", row.Cells("ItemQty").Value)
cmd.Parameters.AddWithValue("#ItemPrice", row.Cells("ItemPrice").Value)
cmd.Parameters.AddWithValue("#discount", row.Cells("discount").Value)
cmd.Parameters.AddWithValue("#subtotal", row.Cells("subtotal").Value)
cmd.Parameters.AddWithValue("#Ref", preftxt.Text.ToString)
cmd.Parameters.AddWithValue("#Suppnum", Convert.ToInt32(pnumtxt.Text))
cmd.Parameters.AddWithValue("#UniqueID", Convert.ToInt32(pautotxt.Text))
DataGridView1.AllowUserToAddRows = False
con.Open()
cmd.ExecuteNonQuery()
con.Close()
End Using
Next
'This the code i used to show the data in datagridview:
Private Sub NewPurchaseInvoice_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim con As New OleDbConnection
con.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source= C:\Users\PU-IMO\Desktop\BlueWavesIS - Copy\BlueWavesIS\BlueWavesIS.accdb"
con.Open()
Dim sql As String = "Select [Itemnum],[Itemname],[Itemprice],[ItemQty],[discount],[subtotal] from PurchaseInvoice where [UniqueID] = " & pautotxt.Text & ""
Dim cmd10 As OleDbCommand = New OleDbCommand(Sql, con)
'Dim adap As New OleDbDataAdapter("Select [Itemnum],[Itemname],[Itemprice],[discount],[subtotal] from PurchaseInvoice where UniqueID = " & pautotxt.Text & "", con)
'Dim ds As New System.Data.DataSet
'adap.Fill(ds, "PurchaseInvoice")
Dim dr As OleDbDataReader = cmd10.ExecuteReader
Do While dr.Read()
DataGridView1.Rows.Add(dr("ItemNum"), dr("ItemName"), dr("ItemQty"), dr("ItemPrice"), dr("discount"), dr("subtotal"))
Loop
con.Close()
I expect that all the rows will be updated as each other, but the actual output is that each row has different qty name etc...
This code does not seem appropriate in the load event because pautotxt.Text will not have a value yet. Can you move it to a Button.Click?
I guessed that the datatype of ID is an Integer. You must first test if the the .Text property can be converted to an Integer. .TryParse does this. It returns a Boolean and fills IntID that was provided as the second parameter.
You can pass the connection string directly to the constructor of the connection. The Using...End Using blocks ensure that your database objects are closed and disposed even if there is an error. You can pass the Select statement and the connection directly to the constructor of the command.
ALWAYS use Parameters, never concatenate strings to avoid sql injection. Don't use .AddWithValue. See http://www.dbdelta.com/addwithvalue-is-evil/
and
https://blogs.msmvps.com/jcoehoorn/blog/2014/05/12/can-we-stop-using-addwithvalue-already/
and another one:
https://dba.stackexchange.com/questions/195937/addwithvalue-performance-and-plan-cache-implications
The DataAdapter will open the connection, fiil the DataTable and close the connection if it finds it closed; however if it is found open it will leave it open.
The last line binds the grid to the DataTable.
Private Sub FillGrid()
If Not Integer.TryParse(pautotxt.Text, IntID) Then
MessageBox.Show("Please enter a number")
Return
End If
dt = New DataTable()
Using con As New OleDbConnection(ConnString)
Using cmd As New OleDbCommand(Sql, con)
cmd.Parameters.Add("#ID", OleDbType.Integer).Value = IntID
Dim adap = New OleDbDataAdapter(cmd)
adap.Fill(dt)
End Using
End Using
DataGridView1.DataSource = dt
End Sub
DataTables are very clever. When bound to a DataGridView they keep track of changes and mark rows as update, insert, or delete. The DataAdapter uses this info to update the database. Once the database is updated we call .AcceptChanges on the DataTable to clear the marking on the rows.
Private Sub UpdateDatabase()
Using cn As New OleDbConnection(ConnString)
Using da As New OleDbDataAdapter(Sql, cn)
da.SelectCommand.Parameters.Add("#ID", OleDbType.Integer).Value = IntID
Using builder As New OleDbCommandBuilder(da)
da.Update(dt)
End Using
End Using
End Using
dt.AcceptChanges()
End Sub
I can select the data from an Access database, but I tried many ways to INSERT INTO database. There is no error message, but it didn't insert the data.
Code:
Dim conn As New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & CurDir() & "\fsDB1.accdb")
Dim cmd As OleDbCommand
Dim dr As OleDbDataReader
conn.Open()
Dim CommandString As String = "INSERT INTO tblfile(stdUname,filePw,filePath,status) VALUES('" & userName & "','" & filePw & "','" & filePath & "','A')"
Dim command As New OleDbCommand(CommandString, conn)
Command.Connection = conn
Command.ExecuteNonQuery()
I just want a simple easy way to INSERT INTO an Access database. Is it possible because of the problem of Access database? I can insert this query by running query directly in Access.
Firstly I would check the database settings. If your app copies a new copy of the database each time you run it that would explain why you can select existing data and why your new data is not being saved (Well it is being saved, but the database keeps getting replaced with the old one). Rather set it up to COPY IF NEWER.
Further, you should ALWAYS use parameterized queries to protect your data. It is also is less error prone than string concatenated commands ans is much easier to debug.
Also, I recommend using a USING block to handle database connections so that your code automatically disposes of resources no longer needed, just in case you forget to dispose of your connection when you are done. Here is an example:
Using con As New OleDbConnection
con.ConnectionString = "Provider = Microsoft.ACE.OLEDB.12.0; " & _
"Data Source = "
Dim sql_insert As String = "INSERT INTO Tbl (Code) " & _
"VALUES " & _
"(#code);"
Dim sql_insert_entry As New OleDbCommand
con.Open()
With sql_insert_entry
.Parameters.AddWithValue("#code", txtCode.Text)
.CommandText = sql_insert
.Connection = con
.ExecuteNonQuery()
End With
con.Close()
End Using
Here is an example where data operations are in a separate class from form code.
Calling from a form
Dim ops As New Operations1
Dim newIdentifier As Integer = 0
If ops.AddNewRow("O'brien and company", "Jim O'brien", newIdentifier) Then
MessageBox.Show($"New Id for Jim {newIdentifier}")
End If
Back-end class where the new primary key is set for the last argument to AddNewRow which can be used if AddNewRow returns true.
Public Class Operations1
Private Builder As New OleDbConnectionStringBuilder With
{
.Provider = "Microsoft.ACE.OLEDB.12.0",
.DataSource = IO.Path.Combine(AppDomain.CurrentDomain.BaseDirectory, "Database1.accdb")
}
Public Function AddNewRow(
ByVal CompanyName As String,
ByVal ContactName As String,
ByRef Identfier As Integer) As Boolean
Dim Success As Boolean = True
Dim Affected As Integer = 0
Try
Using cn As New OleDbConnection With {.ConnectionString = Builder.ConnectionString}
Using cmd As New OleDbCommand With {.Connection = cn}
cmd.CommandText = "INSERT INTO Customer (CompanyName,ContactName) VALUES (#CompanyName, #ContactName)"
cmd.Parameters.AddWithValue("#CompanyName", CompanyName)
cmd.Parameters.AddWithValue("#ContactName", ContactName)
cn.Open()
Affected = cmd.ExecuteNonQuery()
If Affected = 1 Then
cmd.CommandText = "Select ##Identity"
Identfier = CInt(cmd.ExecuteScalar)
Success = True
End If
End Using
End Using
Catch ex As Exception
Success = False
End Try
Return Success
End Function
End Class
I have two(2) MS Access databases with different connections in different location. Deleting records from the table of the first database is working but inserting new records that was copied from the table of the second database is not working. The table of the first database remains blank. What happened was it was inserted the new records to the table of the second database, that's why the second database have many records because it copied and inserted to itself. What I want is that the copied records from second database will be pasted/inserted to the first database.
SQLStr1 is the location string of the first database
SQLStr2 is the location string of the second databas
Dim conn As OleDbConnection
Dim conn2 As OleDbConnection
Dim cmd As OleDbCommand
Dim cmd2 As OleDbCommand
Dim SQLStr1 As String
Dim SQLStr2 As String
conn = New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=psipop.accdb;Jet OLEDB:Database Password=cscfo13poppsi;")
'I used 'psipop' because the database is located the same with the application.
SQLStr1 = "DELETE * FROM pop 'psipop'"
conn.Open()
cmd = New OleDbCommand(SQLStr1, conn)
cmd.ExecuteNonQuery()
'I used " & TextBox3.Text & " because the textbox3 contains the path of the another database.
conn2 = New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source= '" & TextBox3.Text & "' ;Jet OLEDB:Database Password=cscfo13poppsi; ")
SQLStr2 = "INSERT INTO pop SELECT * FROM pop IN '" & TextBox3.Text & "'"
conn2.Open()
cmd2 = New OleDbCommand(SQLStr2, conn2)
cmd2.ExecuteNonQuery()
Please help me to this. Thank you.
E.g.
Using sourceConnection As New OleDbConnection("source connection string here"),
destinationConnection As New OleDbConnection("source connection string here"),
insertCommand As New OleDbCommand("INSERT statement here", destinationConnection),
adapter As New OleDbDataAdapter("SELECT statement here", sourceConnection) With {.InsertCommand = insertCommand,
.AcceptChangesDuringFill = False}
Dim table As New DataTable
adapter.Fill(table)
adapter.Update(table)
End Using
That will populate the DataTable from one database and insert the rows into the other. You'll need to configure the insertCommand with appropriate parameters. Take special note of the AcceptChangesDuringFill property, which ensures that all DataRows have a RowState of Added and are therefore ready to be inserted. Without that, all RowState properties will be Unchanged and nothing will get saved.
I'm trying to pass this Update command to a database, it completes ok with no errors but it doesnt update the database and I can't understand why?
Dim Cmd As OleDbCommand
Dim SQL As String
Dim objCmd As New OleDbCommand
Dim Con = New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" & My.Settings.MasterPath)
Dim Item = "08/08/2015"
SQL = ("UPDATE [Hol Dates] SET [" & EmployeeList.Text & "]= #Htype WHERE [HDate]=#Hdate")
Cmd = New OleDbCommand(SQL, Con)
objCmd = New OleDbCommand(SQL, Con)
objCmd.Parameters.AddWithValue("#Hdate", item)
objCmd.Parameters.AddWithValue("#Htype", "None")
Con.Open()
Dim ans = MsgBox("Do you want to unbook this holiday?", MsgBoxStyle.YesNo)
If ans = MsgBoxResult.Yes Then
objCmd.ExecuteNonQuery()
Else
Exit Sub
End If
Con.Close()
Con.Dispose()
You need to reverse the order in which you add the parameters to the OleDbCommand object. OleDb allows us to assign names to parameters but it ignores the names and only pays attention to the order in which the parameters appear in the CommandText.
Therefore, since your SQL statement refers to Htype and then Hdate you need to add the parameters in that same order.