ADD SQL QUERY STAT - sql

Question

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

Answer 1

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.