mComDriver.Read_DB

[PoLLo]

Hi,

I managed how to get data from database using read_db function from activex.dll in vb6. I want to read whith copymemory function a float value from database but i get a large decimal number with cientific notation. Also i cannot read the entire database, so im doing it in groups of 19 cuz if i do 20 i get an error "9 Subscript out of range". Here is my code:

 

Private Sub LeerBD()
    Dim Valores() As Byte
    Dim i As Integer
    Dim iFecha As String
    Dim iHora As String
    Dim iTipo As String
    Dim iLote As Long
    Dim iTemCam As Double
    Dim iHumedad As Integer
    Dim iPresion As Integer
    Dim iPeso As Double
    Dim iEst As String
    Dim Pointer As Long
    Dim grupo As Long
    
    On Error GoTo mal
    
    For grupo = 0 To 101949 Step 19 * 51
    
        Call mComDriver.Read_DB(grupo, 19, 51, 51, Valores)
        Pointer = 0      
        For i = 1 To 19
            iFecha = PointerToString(VarPtr(Valores(Pointer)))
            Pointer = Pointer + 10
            iHora = PointerToString(VarPtr(Valores(Pointer)))
            Pointer = Pointer + 10
            iTipo = PointerToString(VarPtr(Valores(Pointer)))
            Pointer = Pointer + 10
            Call CopyMemory(iLote, Valores(Pointer), 4)
            Pointer = Pointer + 4
            Call CopyMemory(iTemCam, Valores(Pointer), 4)
            Pointer = Pointer + 4
            Call CopyMemory(iHumedad, Valores(Pointer), 2)
            Pointer = Pointer + 2
            Call CopyMemory(iPresion, Valores(Pointer), 2)
            Pointer = Pointer + 2
            Call CopyMemory(iPeso, Valores(Pointer), 4)
            Pointer = Pointer + 4
            iEst = PointerToString(VarPtr(Valores(Pointer)))
            Pointer = Pointer + 5
            Debug.Print iFecha & "-" & iHora & "-" & iTipo & "-" & iLote & "-" & iTemCam & "-" & iHumedad & "-" & iPresion & "-" & iPeso & "-" & iEst
        Next i
    Next grupo
    Exit Sub
mal:
    MsgBox "[" & Err.Number & "] " & Err.Description, vbCritical, "Error"
End Sub

the results for iTemCam or iPeso are like this:

8.39516345413446E-320

1.27321882187115E-314

Any ideas what im doing wrong?

[Ofir]

Hi,

Please define  iTemCam and iPeso  as float instead of double.