Help, My code fails on da.fill(dt). The error says OleDBexception was unhandled
no value given for one or more required parameter
My code
Dim Conn As OleDb.OleDbConnection = New OleDb.OleDbConnection
Dim connString As String
Dim da As OleDb.OleDbDataAdapter
Dim dt As New DataTable
Dim oCmd As OleDb.OleDbCommand
Dim SQLString As String
connString = "PROVIDER=Microsoft.Jet.OLEDB.4.0;Data Source =" & sRemoteAccessFolder & "Projects.MDB"
Conn.ConnectionString = connString
Conn.Open()
SQLString = "select * from tblProjects where ProjectNumber='10100'"
da = New OleDb.OleDbDataAdapter(SQLString, Conn)
da.Fill(dt)
Any idea?
thx u
This line has problems probably:
SQLString = "select * from tblProjects where ProjectNumber='10100'"
The field ProjectNumber has to match what is in the table. If there is a space, then you need to include brackets:
SQLString = "select * from tblProjects where [Project Number]='10100'"
If it's a numeric field, then drop the quotes:
SQLString = "select * from tblProjects where [Project Number]=10100"
If you still have errors, then make sure you have a table called tblProjects in the database.
As always, make sure to use Parameters instead of doing the sql statement completely by hand. That will avoid potential sql injection issues.
I haven't used it for long time. But may be do as follow.
connString = "PROVIDER=Microsoft.Jet.OLEDB.4.0;Data Source =" & sRemoteAccessFolder & "Projects.MDB"
Conn.ConnectionString = connString
Conn.Open()
Dim oCmd As new OleDb.OleDbCommand
oCmd.CommandText= "select ...."
Dim da As OleDb.OleDbDataAdapter
Dim dt As New DataTable
da = New OleDb.OleDbDataAdapter(oCmd)
da.Fill(dt)
The same thing happened in my project as well.
SQLString = "select * from tblProjects where ProjectNumber='10100'"
I followed the same and concluded this way it helped me. The correct statement which worked for me is
SQLString = "select * from tblProjects where [ProjectNumber]='10100'"
Related
I'm trying to select the name of a customer based on the selected code from a ComboBox. When I run the following code, I get an error saying that there's no value for one or more required parameters.
sql = "SELECT [Customer_Name] FROM [Customers] WHERE [Customer_Code] = #code"
Dim cmd As New OleDb.OleDbCommand(sql, con)
cmd.Parameters.Add("#code", OleDb.OleDbType.VarChar).Value = cmbCustomer.Text
Dim da As New OleDb.OleDbDataAdapter(sql, con)
Dim ds As New DataSet
da.Fill(ds)
txtCustomer.Text = ds.Tables(0).Rows(0).Item("Customer_Name")
However, when I run the same query but without the parameter, it works fine.
sql = "SELECT [Customer_Name] FROM [Customers] WHERE [Customer_Code] = '" & cmbCustomer.Text & "'"
Dim cmd As New OleDb.OleDbCommand(sql, con)
Dim da As New OleDb.OleDbDataAdapter(sql, con)
Dim ds As New DataSet
da.Fill(ds)
txtCustomer.Text = ds.Tables(0).Rows(0).Item("Customer_Name")
Is there something really obvious that I've missed with the first way of doing it? If not, why is this way not working?
It's because of the OleDbDataAdapter
You're setting the DataAdapter to take the string of sql, and connection of con, which means the cmd.Parameter is not passed in with it.
So your code would be looking for da.SelectCommand.Parameters.Add.
You either need
da.SelectCommand.Parameters.Add("#Code", OleDb.OleDbType.VarChar).Value = cmbCustomer.Text
Or
Dim da As New OleDb.OleDbDataAdapter(cmd)
I am relatively new to programming in VB.
Currently, I have a login page that works fine. After successful login, my user is directed to another form which connects back into an MS Access table and presents data on the screen for them.
I take the logged in user and equal it to a label on the secondary form (after they login). Basically I want to have a SQL select statement for if the Username column in my access db equals that label, then to pull back the data for that unique user. Here is my current code:
lblUsername.Text = login.txtUsername.Text
DbProvider = "PROVIDER=Microsoft.Jet.OLEDB.4.0;"
DbSource = "Data Source = C:\loginprogram\studentclasslist.mdb"
con.ConnectionString = DbProvider & DbSource
con.Open()
strSQL = "SELECT * FROM Table1 WHERE Username = '" + Label1.Text + "'""
da = New OleDb.OleDbDataAdapter(strSQL, con)
da.Fill(ds, "studentclasslist")
con.Close()
It doesn't work. When I take the where statement out and just do "Select * From Table1" it works fine, but doesn't give me a unique logged in user, which is my goal.
Please help!
You should store your login user id in the session when user logged in successfully.
//In your login page
Session["myUser"] = txtUsername.Text
Then, you can use the user id from Session anywhere in your application.
//In your other page.
Dim Cmd As OleDbCommand = connection.CreateCommand()
Cmd.CommandText = "SELECT * FROM Table1 WHERE Username=?"
Cmd.Parameters.Add("#Username",OleDbType.Text,50).Value = Session["myUser"]
Dim da As New OleDbDataAdapter(Cmd)
Dim dt As New DataTable()
da.Fill(dt)
It din't work because of, misused double quotation.
May be Something like this
lblUsername.Text = login.txtUsername.Text
DbProvider = "PROVIDER=Microsoft.Jet.OLEDB.4.0;"
DbSource = "Data Source = C:\loginprogram\studentclasslist.mdb"
con.ConnectionString = DbProvider & DbSource
con.Open()
strSQL = "SELECT * FROM Table1 WHERE Username = '" & Label1.Text & "'"
da = New OleDb.OleDbDataAdapter(strSQL, con)
da.Fill(ds, "studentclasslist")
con.Close()
But this will leads you to SQL injection attacks. use parameterized queries to treat input as values in your SQL queries.
lblUsername.Text = login.txtUsername.Text
DbProvider = "PROVIDER=Microsoft.Jet.OLEDB.4.0;"
DbSource = "Data Source = C:\loginprogram\studentclasslist.mdb"
con.ConnectionString = DbProvider & DbSource
con.Open()
strSQL = "SELECT * FROM Table1 WHERE Username = #UserName"
da = New OleDb.OleDbDataAdapter(strSQL, con)
da.SelectCommand.Parameters.Add("#UserName",SqlDbType.nvarchar,50).Value = Label1.Text
da.Fill(ds, "studentclasslist")
con.Close()
To prevent from SQL injection as parameters as already been widely suggested. Additionally, you could use Using for you connection to dispose right away the connection after it is being used like:
Using con As New OleDbConnection(DbProvider & DbSource)
con.Open()
strSQL = "SELECT * FROM Table1 WHERE Username = #UserName"
da = New OleDb.OleDbDataAdapter(strSQL, con)
da.SelectCommand.Parameters.Add("#UserName",SqlDbType.nvarchar,50).Value = Label1.Text
da.Fill(ds, "studentclasslist")
End Using
Secondly, you can put the data on a DataTable
Dim dt as new DataTable
dt = ds.Tables(0)
And assuming that you have one record match you could check if there are records by checking Records.Count and if there is save it to a DataRow and then Textboxes.
If (dt.Rows.Count > 0) Then
Dim dr as DataRow = dt.Rows(0)
'Field names and Textbox names below are just mine
txtUserName.Text = dr.Item("Username")
txtPassword.Text = dr.Item("Password")
txtUserlevel.Text = dr.Item("UserLevel")
End If
So, all in all it would probably look like this:
lblUsername.Text = login.txtUsername.Text
DbProvider = "PROVIDER=Microsoft.Jet.OLEDB.4.0;"
DbSource = "Data Source = C:\loginprogram\studentclasslist.mdb"
Using con As New OleDbConnection(DbProvider & DbSource)
Dim dt as new DataTable
con.Open()
strSQL = "SELECT * FROM Table1 WHERE Username = #UserName"
da = New OleDb.OleDbDataAdapter(strSQL, con)
da.SelectCommand.Parameters.Add("#UserName",SqlDbType.nvarchar,50).Value = Label1.Text
da.Fill(ds, "studentclasslist")
dt = ds.Tables(0)
If (dt.Rows.Count > 0) Then
Dim dr as DataRow = dt.Rows(0)
'Field names and Textbox names below are just mine
txtUserName.Text = dr.Item("Username")
txtPassword.Text = dr.Item("Password")
txtUserlevel.Text = dr.Item("UserLevel")
End If
End Using
thanks everyone. it was the double quote. works now but next is making it sql injection proof which i will learn how to use parameterized queries to prevent against.
I'm trying to update the records from textboxes into the Access database, I'm wondering every time I hit save, it generates an error
An unhandled exception of type 'System.Data.OleDb.OleDbException' occurred in System.Data.dll
Additional information: No value given for one or more required parameters.
Highlighting .ExecuteNonQuery()
What does it mean? It's preventing me to run my code :(
Private Sub SaveButton_Click(sender As Object, e As EventArgs) Handles SaveButton.Click
Dim empNum As String
Dim empFname As String
Dim empLname As String
Dim empDept As String
Dim empStat As String
Dim empYears As String
empNum = eNumText.Text
empFname = empFnameText.Text
empLname = empLnameText.Text
empDept = DeptText.Text
empStat = StatText.Text
empYears = yearstext.Text
con.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0; Data Source= c:\Databse\Company_db.accdb"
con.Open()
Dim SqlAdapter As New OleDbDataAdapter
Dim Table As New DataTable
Dim sqlQuery As String = "UPDATE tbl_empinfo " & _
"SET FirstName=empFname, LastName=empLname, Department=empDept, " & _
"Status=empStat, Years=empYears " & _
"WHERE empID=empNum"
Dim cmd As New OleDbCommand
With cmd
.CommandText = sqlQuery
.Connection = con
.Parameters.AddWithValue("FirstName", empFname)
.Parameters.AddWithValue("LastName", empLname)
.Parameters.AddWithValue("Department", empDept)
.Parameters.AddWithValue("Status", empStat)
.Parameters.AddWithValue("Years", empYears)
.ExecuteNonQuery()
End With
Using cmd2 = New OleDbCommand(sqlQuery, con)
cmd.Parameters.AddWithValue("FirstName", empFname)
cmd.Parameters.AddWithValue("LastName", empLname)
cmd.Parameters.AddWithValue("Department", empDept)
cmd.Parameters.AddWithValue("Status", empStat)
cmd.Parameters.AddWithValue("Years", empYears)
cmd.ExecuteNonQuery()
End Using
sqlQuery = "SELECT * FROM tbl_empinfo "
Dim cmd1 As New OleDbCommand
Dim da As New OleDbDataAdapter
With cmd1
.CommandText = sqlQuery
.Connection = con
With SqlAdapter
.SelectCommand = cmd1
.Fill(Table)
End With
With DataGridView1
.DataSource = Table
End With
End With
con.Close()
End Sub
You are trying to set an UPDATE command text for the SelectCommand of the Adapter. This, of course has no way to be successful. Last but not least the UPDATE command text doesn't contain a WHERE clause, and so, if executed, it updates every record in the table tbl_empinfo with the same data.
In this context there is no need to use an adapter. You could simply execute the command, providing an appropriate WHERE clause and the values for the other parameters
Dim sqlQuery As String = "UPDATE tbl_empinfo " & _
"SET FirstName=?, LastName=?, Department=?, " & _
"Status=?, Years=? " & _
"WHERE empID=?"
Dim cmd As New OleDbCommand
With cmd
.CommandText = sqlQuery
.Connection = con
.Parameters.AddWithValue("#p1", empFName)
.Parameters.AddWithValue("#p2", empLName)
.Parameters.AddWithValue("#p3", empDept)
.Parameters.AddWithValue("#p4", empStat)
.Parameters.AddWithValue("#p5", empYears)
.Parameters.AddWithValue("#p6", empNum)
.ExecuteNonQuery()
End With
After this you could call the code that reloads the data to fill your grid
sqlQuery = "SELECT * FROM tbl_empinfo"
Dim cmd1 As New OleDbCommand
Dim da As New OleDbDataAdapter
Dim Table As New DataTable
With cmd1
.CommandText = sqlQuery
.Connection = con
With da
.SelectCommand = cmd1
.Fill(Table)
End With
With DataGridView1
.DataSource = Table
End With
End With
Notice that I have changed the name of the command and the adapter to a less confusing names. SqlCommand And SqlDataAdapter are the names of the classes equivalent to the OleDbCommand and OleDbDataAdapter but used for Sql Server. At first sight I was thinking that you were trying to use the SqlClient classes to update an MS-Access database.
This is what I've got so far :
Dim myCONN As OleDbConnection = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=w:\Baza.mdb")
Dim cmd1 = New OleDbCommand("SELECT ID FROM Baza WHERE NAZIV=#XXNAZIV")
cmd1.Parameters.AddWithValue("#XXNAZIV", TextBox2.Text)
cmd1.Connection = myCONN
myCONN.Open()
Dim result = cmd1.ExecuteReader()
While (result.Read())
Dim rowx As Integer = GetTextOrEmpty(result("ID"))
End While
I've found the row (rowx) in which I would like to change values in 20 corresponding columns (namesID : NAZIV, SIFRA,...). Data is already presented in textboxes (textbox1...), but I don't know how to finish this code with UPDATE and how to insert changed values back to Access.
Dim cmdText As String = "UPDATE Baza SET NAZIV=#XXNAZIV Where ID=SomeId"
Using con = new OleDbConnection("PROVIDER=Microsoft.ACE.OLEDB.12.0;Data Source = h:\Baza.mdb")
Using cmd = new OleDbCommand(cmdText, con)
con.Open()
cmd.Parameters.AddWithValue("#XXNAZIV",TextBox2.Text)
cmd.ExecuteNonQuery()
End Using
End Using
This should help you to solve your problem, of course you will have to pass ID parameter to query also.
Reference
i have a problem in displaying the data in crystal reports using left join because its duplicating my data even though i am using GROUP BY in sqlcommand.
here is the list of my tables:
table 1: complaint
table 2: errordesc (error description)
here is my code in crystal reports:
Dim objConn As MySqlConnection
Dim daT1, daT2 As MySqlDataAdapter
Dim activecomp As DataSet
Dim strConnection As String
Dim strSQL As String
strConnection = "server=localhost;user id=root;password=;database=ticketing_system;"
objConn = New MySqlConnection(strConnection)
objConn.Open()
strSQL = "SELECT * FROM errordesc LEFT JOIN complaint ON errordesc.tran_no=complaint.tran_no WHERE errordesc.status='On-process' group by errordesc.err_id "
daT1 = New MySqlDataAdapter(strSQL, objConn)
activecomp = New DataSet
daT1.Fill(activecomp, "comp")
daT1.Fill(activecomp, "active")
Dim rpt As New CrystalReport1
rpt.SetDataSource(activecomp)
CrystalReportViewer1.ReportSource = rpt
objConn.Close()
and my outout was this:
it duplicated my errordesc.err_id even thought i grouped it. :( please help if anyone know. thanks in advance...
i think that the simple way to remove your duplicate rows is changing your strSQL:
strSQL = "SELECT DISTINCT * FROM errordesc LEFT JOIN "+
"complaint ON errordesc.tran_no=complaint.tran_no "+
"WHERE errordesc.status='On-process' group by errordesc.err_id "
oohh. i solved my own problem by coding my to crystal reports like this:
Dim objConn As MySqlConnection
Dim daT1, daT2 As MySqlDataAdapter
Dim activecomp As DataSet
Dim strConnection As String
Dim strSQL As String
strConnection = "server=localhost;user id=root;password=;database=ticketing_system;"
objConn = New MySqlConnection(strConnection)
objConn.Open()
strSQL = "SELECT * FROM errordesc WHERE errordesc.status='On-process' group by errordesc.err_id "
daT1 = New MySqlDataAdapter(strSQL, objConn)
activecomp = New DataSet
daT1.Fill(activecomp, "errordesc")
strSQL = "SELECT * FROM complaint left join errordesc on complaint.tran_no=errordesc.tran_no group by complaint.tran_no"
daT2 = New MySqlDataAdapter(strSQL, objConn)
daT2.Fill(activecomp, "complaint")
Dim rpt As New CrystalReport1
rpt.SetDataSource(activecomp)
CrystalReportViewer1.ReportSource = rpt
objConn.Close()