Microsoft KB Archive/250970

Knowledge Base

ACC: How to Write More than 255 Columns to a File

Article ID: 250970

Article Last Modified on 1/27/2007

---

APPLIES TO

• Microsoft Access 95 Standard Edition
• Microsoft Access 97 Standard Edition

---

This article was previously published under Q250970

Advanced: Requires expert coding, interoperability, and multiuser skills.

SUMMARY

Because Microsoft Access has a limit of 255 columns in a table or a query, you cannot export text files that must have more than 255 columns as you usually would. This article shows you how you can export text files (sometimes referred to as flat files) that have more than 255 columns. The method described in this article uses a query to split the data, and then uses Visual Basic for Applications to export the information into one file.

MORE INFORMATION

Microsoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements. CAUTION: If you follow the steps in this example, you modify the sample database Northwind.mdb. You may want to back up the Northwind.mdb file and follow these steps on a copy of the database.

The sample code contained in this article works with separate recordset objects, and uses sequential file statements to export all the data. This example uses two queries to split the Customers table in Northwind.mdb. To preserve the integrity of the data, both queries should have the same number of records, and they should be sorted in the same order.

1. Create the first query as follows:

      Query: qryCustomers1
      --------------------
      Type: Select Query
   
      Field: CustomerID
      Table: Customers
   
      Field: CompanyName
      Table: Customers
   
      Field: ContactName
      Table: Customers
   
      Field: ContactTitle
      Table: Customers
                       

2. Create the second query as follows:

      Query: qryCustomers2
      --------------------
      Type: Select Query
   
      Field: Address
      Table: Customers
   
      Field: City
      Table: Customers
   
      Field: Region
      Table: Customers
   
      Field: PostalCode
      Table: Customers
   
      Field: Country
      Table: Customers
   
      Field: Phone
      Table: Customers
   
      Field: Fax
      Table: Customers
                       

3. Create a module, and then type the following line in the Declarations section if it is not already there:

   Option Explicit
                       

4. Type the following procedure:

    
   Sub WriteFlatFile(sFileName As String, sDelimiter As String)
   
       On Error GoTo WriteFileErrors
   
       Dim rst1 As DAO.Recordset
       Dim rst2 As DAO.Recordset
       Dim fld1 As DAO.Field
       Dim fld2 As DAO.Field
       
       'Counter variable used to print the delimiter except after
       'the last field for rst2
       Dim intCount As Integer
       
       'Delete the specified file if it already exists
       If Dir(sFileName) <> "" Then
           If MsgBox("The file you entered already exists.  Would you " _      
           & "like to delete it?", vbExclamation + vbYesNo) = vbYes Then
               Kill sFileName
           Else
               Exit Sub
           End If
       End If
       
       'Create a separate recordset for each query
       Set rst1 = CurrentDb().OpenRecordset("qryCustomers1")
       Set rst2 = CurrentDb().OpenRecordset("qryCustomers2")
       
       'Open the file using the Open statement
       Open sFileName For Output As #1
       
       'Write the header row from both recordsets using the Print statement
       For intCount = 0 To rst1.Fields.Count - 1
           Print #1, rst1(intCount).Name & sDelimiter;
       Next
       
       'This uses a counter variable to see determine if we are writing the
       'last field. If we are, do not print the delimiter. Only check this   
       'for the end of the second recordset, to make sure there is a delimiter 
       'between the 2 recordsets
       For intCount = 0 To rst2.Fields.Count - 1
           If intCount < rst2.Fields.Count - 1 Then
               Print #1, rst2(intCount).Name & sDelimiter;
           Else
               Print #1, rst2(intCount).Name;
           End If
       Next
       
       'Write new line
       Print #1,
       
       'Write the data from each recordset
       Do While Not rst1.EOF And Not rst2.EOF
           For intCount = 0 To rst1.Fields.Count - 1
               Print #1, rst1(intCount).Value & sDelimiter;
           Next
           rst1.MoveNext
           
           For intCount = 0 To rst2.Fields.Count - 1
               If intCount < rst2.Fields.Count - 1 Then
                   Print #1, rst2(intCount).Value & sDelimiter;
               Else
                   Print #1, rst2(intCount).Value;
               End If
           Next
           rst2.MoveNext
           
           'write to new line
           Print #1,
       Loop
   
       MsgBox "File has been written to " & sFileName
       
   WriteFileExit:
       'Close objects and destroy DAO object variables
       rst1.Close
       rst2.Close
       Set rst1 = Nothing
       Set rst2 = Nothing
       
       'close the sequential file opened earlier
       Close #1
       
       Exit Sub
   
   WriteFileErrors:
       MsgBox "An error has occurred: " & vbCrLf & Err.Number & " " & Err.Description
       Resume WriteFileExit
   End Sub
                       

5. To test this procedure, type the following line in the Debug window, and then press ENTER:

   WriteFlatFile "c:\testfile.txt",","
                           

   Note that a comma delimited file, C:\Testfile.txt, has been created, and that the entire Customers table has been exported to this file.

Additional query words: OFF97 ACC97 ACC95

Keywords: kbhowto KB250970

---

Send feedback to Microsoft

© Microsoft Corporation. All rights reserved.