Resolving Connection Problems

If your application cannot connect to the external data source, check the following:

• Make sure you can access the external table through the file system. If the table is stored on a network share, for example, verify that you have sufficient privileges to access that share.
  
  
• Check that the external table is accessible through its native application. For example, if you’re trying to open a Microsoft Excel worksheet, verify that you can open the worksheet in Microsoft Excel.
  
  
• Check the code that establishes the connection to the external table carefully to make sure that it follows the guidelines in the “Establishing a Connection” section earlier in this chapter.
  
  
• If you were able to connect to the external table through your application before but you cannot now, make sure that the table is still in its original location. If the table is linked in your Microsoft Jet database and it has been moved, see the “Maintaining Links” section earlier in this chapter.
  
  
• If you receive the message “Unable to find installable ISAM,” check the source database type value in the table in the “Specifying Source Database Types” section earlier in this chapter. (Remember that Excel 7.0 is not a valid source database type; use Excel 5.0 instead.)
  
  
• If the source database type matches one of the values in the table in the “Specifying Source Database Types” section, make sure that the IISAM driver resides in the directory specified in the registry.
  
  
• If you are supplying arguments to a case-sensitive data source, make sure that the arguments are of the correct form and case.
  
  
• Check the system on which the external data source resides for sufficient disk space.