Checkbox Yes/No Change on Dropbox Change - vba

Question

I have a Combo Box (cbo1) that list available Items. When I select an item in cbo1, I would like it change a checkbox to True (or Yes).
cbo1 gets data from tblLOG where Box (checkbox) is NO Query
I've tried using
UPDATE tblLOG
Set Box = True
WHERE Serial = cboSerial
Actual Code.
Private Sub cbo1_Change()
Dim strSQL As String
Dim i As Integer
Dim Msg As String
Dim Assm As String
Assm = cbo1.Value
'Exit this sub if the combo box is cleared
Msg = "Make Update" & vbCr & vbCr
i = MsgBox(Msg, vbQuestion + vbYesNo, "UPDATE VALUE?")
If i = vbYes Then
strSQL = "UPDATE tblLOG " _
& "SET Box= True " _
& "WHERE Serial = Assm;"
CurrentDb.Execute strSQL, dbFailOnError
Response = acDataErrAdded
End If
End Sub
My Results are
Run-time error '3061': Too few parameters. Expected 1.

Answer 1

The reason for your error is because you are not evaluating your VBA variable Assm, but rather concatenating the string "Assm" to your SQL query.
strSQL = "UPDATE tblLOG " _
& "SET Box= True " _
& "WHERE Serial = Assm;"
If you were to Debug.Print the variable strSQL to the console, you would see the string:
"UPDATE tblLOG SET Box= True WHERE Serial = Assm;"
However, since Assm is not a string in the SQL query (i.e. it is not surrounded by single or double quotes), it is interpreted as a parameter whose value hasn't been supplied when the SQL query is subsequently executed.
To solve this, you could concatenate the evaluated value of the Assm variable, e.g.:
strSQL = "UPDATE tblLOG " _
& "SET Box= True " _
& "WHERE Serial = '" & Assm & "';"
This assumes that Serial is a text field - if this is not the case, remove the single quotes from the above.
Your entire code could be condensed somewhat to:
Private Sub cbo1_Change()
If MsgBox("Make Update", vbQuestion + vbYesNo, "UPDATE VALUE?") = vbYes Then
CurrentDb.Execute "update tbllog set box = true where serial = '" & cbo1 & "';", dbFailOnError
Response = acDataErrAdded
End If
End Sub
Though, this is still open to SQL injection, and so a better practice is to parameterise the query, e.g.:
With CurrentDb.CreateQueryDef("", "update tbllog t set t.box = true where t.serial = myserial;")
.Parameters!myserial = cbo1
.Execute
End With