How to Import CSV to Excel with VBA - vba

Question

I Have a Red Lion Data station that records temperatures from about 25 ovens and the data is stored on a network in CSV files. I would like to import this data into an Excel file once every two minutes, but only import the changes after the initial import. After the import, the VBA must release the CSV file for the 2 minutes so that it can be updated by the data station. I have searched the web, this site and the closest thing I have found is the following code. This code looks for changes but it does not import the file. any help would be appreciated.
Dim NextTime As Date
Function LastModTime(FileSpec As String) As Date
'Returns the date-time the file specified by FileSpec (path string) was last modified
Dim fs, f, s
Set fs = CreateObject("Scripting.FileSystemObject")
Set f = fs.GetFile(FileSpec)
LastModTime = f.DateLastModified
End Function
Sub Check4Changes()
'Checks the file FilePath for changes every 60 seconds
'If file has changed, pops up a message box. Stores the
'last modified time in cell M1 of Sheet1
ChDir "Q:\Manufacturing\Equipment\DispatchLogs\logs\7-DES"
Const FilePath As String = "Q:\Manufacturing\Equipment\DispatchLogs\logs\7-DES\*.csv"
Dim LastMod As Date
On Error GoTo ReSchedule
LastMod = LastModTime(FilePath)
With Worksheets("Sheet1").Range("C1")
If IsEmpty(.Value) Then
.Value = LastMod
GoTo ReSchedule
ElseIf .Value < LastMod Then
.Value = LastMod
MsgBox FilePath & " updated.", vbInformation, "Check4Changes"
End If
End With
ReSchedule:
'Reschedule this same routine to run in one minute.
NextTime = Now + 2 / 1440
Application.StatusBar = "Next check at " & NextTime
Application.OnTime NextTime, "Check4Changes"
End Sub
Sub CancelChecking()
Application.OnTime NextTime, "Check4Changes", Schedule:=False
Application.StatusBar = False
End Sub

Answer 1

I have written some code which will give you the basic idea
Sub Main()
Dim Wbk_CSV As Excel.Workbook
Dim Excel_Wbk As Excel.Workbook
Dim Var_WholeCSVData As Variant
Dim Var_ExcelData As Variant
Dim Var_ToUpdate As Variant
Dim NumOfRows As Long
Dim Last_Row As Long
Set Wbk_CSV = Workbooks.Open("PathWithFileName")
Wbk_CSV.Sheets(1).Activate
Last_Row = ActiveSheet.Cells.SpecialCells(xlCellTypeLastCell).Row
'Taking whole data in a variant
'Change the range as per the data in csv file
Var_WholeCSVData = Wbk_CSV.Sheets(1).Range("A2:D" & Last_Row).Value 'Considering first row as header row and there are 4 columns
'After taking whole data in varinat close csv file without saving
Wbk_CSV.Close savechanges:=False
Set Wbk_CSV = Nothing
'Now open excel file in which data will be updated
Set Excel_Wbk = Workbooks.Open("PathWithFileName")
Excel_Wbk.Sheets(1).Activate
Last_Row = ActiveSheet.Cells.SpecialCells(xlCellTypeLastCell).Row
Var_ExcelData = Excel_Wbk.Sheets(1).Range("A2:D" & Last_Row).Value 'Considering first row as header row
NumOfRows = 0
'This function will return count of updated rows and data to update
Var_ToUpdate = Delete_Duplicates(Var_WholeCSVData, Var_ExcelData, NumOfRows)
Excel_Wbk.Sheets(1).Activate
'paste data
If NumOfRows > 0 Then
ActiveSheet.Range("A" & Last_Row + 1 & ":D" & Last_Row + NumOfRows).Value = Var_ToUpdate
End If
Excel_Wbk.Close savechanges:=True
Set Excel_Wbk = Nothing
'result
MsgBox ("Number of rows imported: " & NumOfRows)
End Sub
Function Delete_Duplicates(Var_FromCSV As Variant, Var_FromExcel As Variant, ByRef NumberOfRowToupdate As Long) As Variant
'using dictinpary objects
Dim dict_Duplicates As Object
Dim i_AddToDict, i, j As Long
Dim Str_value As String
Dim Var_Temp As Variant
Dim lng_temp As Long
Set dict_Duplicates = CreateObject("Scripting.Dictionary")
ReDim Var_Temp(1 To UBound(Var_FromCSV, 1), 1 To UBound(Var_FromCSV, 2))
'Add excel data to dict. by concatenating
'All unique values will be added
For i_AddToDict = 1 To UBound(Var_FromCSV)
Str_value = CStr(Var_FromExcel(i_AddToDict, 1) & Var_FromExcel(i_AddToDict, 2) & Var_FromExcel(i_AddToDict, 3) & Var_FromExcel(i_AddToDict, 4))
If dict_Duplicates.exists(Str_value) Then
'do nothing
Else
dict_Duplicates.Add Str_value, 1
End If
Next i_AddToDict
'looking for values which are not available in excel file
For i = 1 To UBound(Var_FromCSV)
Str_value = CStr(Var_FromCSV(i_AddToDict, 1) & Var_FromCSV(i_AddToDict, 2) & Var_FromCSV(i_AddToDict, 3) & Var_FromCSV(i_AddToDict, 4))
If dict_Duplicates.exists(Str_value) Then
'do nothing
Else
'storing values in a variant
For j = 1 To 4
Var_Temp(lng_temp, j) = Var_FromCSV(i, j)
Next j
lng_temp = lng_temp + 1
dict_Duplicates.Add Str_value, 1
End If
Next i
NumberOfRowToupdate = lng_temp - 1
Delete_Duplicates = Var_Temp
End Function