Import Data from Microsoft Excel
October 21, 2005
Maybe you have noticed that Excel spreadsheets do not always import data very nicely into Access. Sure, Access can import data from various sources with just a few clicks, but Excel files seem to give the most grief. Out of necessity, I created a code module that employs automation to loop through rows of an Excel spreadsheet and systematically add data to an Access table, cell by cell. While this is not exactly a "cut and paste" solution for your data import, it does provide a nice starting point.
The Download ... caveat emptor
The download for this article contains a few simple objects that demonstrate how one might implement automation for importing data from a Microsoft Excel spreadsheet. It is NOT an Excel import tool. The downside of automation is that, for the most part, you have to have some idea of how the spreadsheet is constructed in order to import it and there has to be a table waiting as the repository. So, the demo mdb file has the following objects:
The form, shown below, serves simply as a harness for launching the code. The logic behind it is simple and does not allow for the import of any file except the sales.xls, which is also in the download package. The sales_import table is the repository I spoke of earlier and the other table, ImportColumnSpecs, is where the Excel-Column to Access-Field mapping is defined. As should be expected, the module contains the clever bit.
Remember, this is NOT an Excel import utility. Please do not write me to say that the tool doesn't work with your Excel file. It won't! This code is provided as an example and a template for you to design and execute your own import. You will need to study the code in the basFileImport module and modify it according to your needs.
Map the Import
The first step is to map the columns of the Excel to specific fields in an Access table. Our example uses a modified version of the Pubs sales table that I have named sales_import. It has only six fields and it perfectly matches the sales.xls file that contains the data I want to import. I have named the import after the name of the table and for my code to work properly, that must be the case. The column named OrdinalPosition represents the column in Excel. The ExcelColumn field is simply for reference but the AccessField field will be used to determine where to put the data during the import.
The demo database also includes a few other simplified tables from the Pubs database: stores and titles. The same mapping could be defined for both of these tables and the code modified slightly to allow for the import of data into those tables.
On to the code ...
The download contains some extra code for updating the demo form with a status message. This is useful if the import is for thousands of records and you want the user to know that processing is still moving forward. Some code is included to Unlock and Lock the spreadsheet, though the sample file is not password protected. The comments in the code should explain the process in its entirety.
Public Function ProcessFileImport(sFile As String, sTable As String) As String On Error GoTo ProcessFileImport_Error ' Excel object variables Dim appExcel As Excel.Application Dim wbk As Excel.Workbook Dim wks As Excel.Worksheet ' Access object variables Dim dbs As DAO.Database Dim rstRead As DAO.Recordset Dim rstWrite As DAO.Recordset Dim fld As DAO.Field ' Declared variables Dim bytWks As Byte Dim bytMaxPages As Byte Dim intStartRow As Integer Dim strData As String Dim intMaxRow As Integer Dim strSQL As String Dim strMsg As String Dim intLastCol As Integer Dim intRow As Integer Dim intRec As Integer Dim strCurrFld As String Dim intCol As Integer Dim intLen As Integer Dim varValue As Variant Dim lngErrs As Long Const cPassword As String = "xxx999" DoCmd.Hourglass True ' Create the Excel Application, Workbook and Worksheet and Database object Set appExcel = Excel.Application Set wbk = appExcel.Workbooks.Open(sFile) Set dbs = CurrentDb ' Optionally, you can protect / unprotect with a password 'wbk.Unprotect (cPassword) ' You could loop through sheets, but for this example, we'll just do one. bytMaxPages = 1 ' Sometimes there is header info, so the "Start Row" isn't the first one. ' Set this variable to the first row that contains actual data. intStartRow = 2 For bytWks = 1 To bytMaxPages ' Initialize variables on each pass Set wks = Nothing Set rstRead = Nothing intRow = intStartRow ' Load current worksheet. Find used range to determine row count. Set wks = appExcel.Worksheets(bytWks) ' Optionally, you can protect / unprotect with a password 'wks.Unprotect (cPassword) ' You need to figure out how many rows this sheet contains, so to know ' how far down to read. That value is saved in intMaxRow strData = wks.UsedRange.Address intMaxRow = CInt(Mid(strData, InStrRev(strData, "$"))) 'intMaxRow = CInt(Mid(strData, LastInStr(strData, "$"))) strData = "" ' Go get the list of fields for this worksheet from the Field Map table strSQL = "SELECT AccessField, OrdinalPosition FROM ImportColumnSpecs " & _ "WHERE ImportName='" & sTable & "' ORDER BY OrdinalPosition ASC;" Set rstRead = dbs.OpenRecordset(strSQL, dbOpenDynaset) ' If there is a mistake and no specification exists, then exit with message If rstRead.BOF And rstRead.EOF Then strMsg = "The import spec was not found. Cannot continue." MsgBox strMsg, vbExclamation, "Error" Else rstRead.MoveLast rstRead.MoveFirst intLastCol = rstRead.RecordCount ' The name of the import and destination table should be the same for this ' code to function correctly. Set rstWrite = dbs.OpenRecordset(sTable, dbOpenDynaset) Do Until intRow > intMaxRow ' Check row to be sure it is not blank. If so, skip the row For intCol = 1 To intLastCol strData = strData & Trim(Nz(wks.Cells(intRow, intCol), "")) Next If strData = "" Then intRow = intRow + 1 Else intRec = intRec + 1 rstWrite.AddNew Do Until rstRead.EOF ' Loop through the list of fields, processing them one at a time. ' Grab the field name to simplify code and improve performance. strCurrFld = Nz(rstRead!AccessField, "") intCol = rstRead!OrdinalPosition ' Make sure that text fields truncate data at prescribed limits. ' Users may not enter supply more text than the fields can contain. If dbs.TableDefs(sTable).Fields(strCurrFld).Type = dbText Then intLen = dbs.TableDefs(sTable).Fields(strCurrFld).Size varValue = Left(Nz(wks.Cells(intRow, intCol), ""), intLen) Else varValue = wks.Cells(intRow, intCol) End If ' The database schema requires that empty fields contain NULL, not ' the empty string. If varValue = "" Then varValue = Null ' Handle date columns. Sometimes Excel doesn't format them as dates If InStr(1, strCurrFld, "Date") > 0 Then If Not IsDate(varValue) Then If IsNumeric(varValue) Then On Error Resume Next varValue = CDate(varValue) If Err.Number <> 0 Then ' Can't figure out the date. Set to null varValue = Null Err.Clear End If On Error GoTo ProcessFileImport_Error Else lngErrs = lngErrs + 1 varValue = Null End If End If rstWrite.Fields(strCurrFld) = varValue Else ' If not a date field, then just write the value to the rst ' (you may need to validate numeric values too) rstWrite.Fields(strCurrFld) = varValue End If rstRead.MoveNext Loop If Not rstRead.BOF Then rstRead.MoveFirst rstWrite.Update ' Reset the variables for processing of the next record. strData = "" intRow = intRow + 1 End If Loop Set wks = Nothing End If Next Exit_Here: ' Report results strMsg = "Total of " & intRow & " records imported." ProcessFileImport = strMsg ' Cleanup all objects (resume next on errors) ' Optionally, you can protect / unprotect with a password 'wbk.Protect (cPassword) 'wks.Protect (cPassword) On Error Resume Next Set wks = Nothing wbk.Close True Set wbk = Nothing appExcel.Quit Set appExcel = Nothing Set rstRead = Nothing Set rstWrite = Nothing Set dbs = Nothing DoCmd.Hourglass False Exit Function ProcessFileImport_Error: MsgBox Err.Description, vbExclamation, "Error" Resume Exit_Here End Function
Roll you own
If you read through the code, you can see there is a lot of room for customization. In the above example, only one worksheet is processed, but the For Next loop allows for processing of multiple, consecutive pages. What makes this code valuable as a template is the inclusion of little tricks for doing things like unlocking a worksheet and finding the total number of used rows. These are clever bits I never want to have to figure out again.
Another prominent feature of the above code is the piece where I test for date values. If the field name is ShipDate or OrderDate, odds are the data should be in date format. I have seen where Excel converts a date into a number (in VBA dates can be expressed as numbers), which causes the insert to fail unless I convert the number back to a date. The same sort of conversion issues might surround zip codes, which look like numbers but are usually text values (the zip 01201 is not the same as the number 1201) and with percent values that include the percent sign. These text characters may have to be removed for the insert to be successful.
As you can see, it is not an out-of-the-box solution, but hopefully it will give you a starting point to create your own custom import for Microsoft Excel Files.