Merging multiple Excel worksheets is a common task and, of course, there are a number of techniques to help you accomplish this task. The following is an easy way to combine multiple Excel files with access.
Create a link to an Excel workbook in Access: Select External data-Import--excel in Access
In the Get External Data dialog box, select Link to data source by creating a linked table.
You must repeat the process for each Excel workbook until you link them to the database. The results are shown in the following figure.
Start a new query in SQL view and click Create-Other-query design.
Select SQL view in Query tools-design
In SQL view, enter a SELECT statement for all linked Excel tables, use the union operator between each SELECT statement, and enter the SELECT query statement in SQL view
After you run the query, the result will be data that is fetched and merged from all linked files. (www.3lian.com)
As long as the linked Excel file is in the same location, Access automatically refreshes the link to get the latest data each time you open the database. This means you only need to set it once, and then run the federated query each time you need to regroup the Excel file.
By default, however, the Union operator removes any duplicate rows from the data. If you know that there are duplicate rows in your data and you want to keep them, you need to use union ALL to allow repeat rows to be passed.