Microsoft KB Archive/250970
Article ID: 250970
Article Last Modified on 1/27/2007
- 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.
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.
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:
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:
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