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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.

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

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

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

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

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

Microsoft KB Archive/250970

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

SUMMARY

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