I just give you an idea.
You need 2 connections (1st for Access database & 2nd for SQL server database). Create Tables in both databases. Make connection string for those databases. Do code for storing & retrieving data from/into database. Major thing is you need to retrieve data from one database & then save those data in another database, that's all. You can do that by opening the database connections & doing manipulations with two databases.
Example.
- Open database connection in Ms Access
- Save data in Ms Access Database
- Now retrieve data from Ms Access Database
- Open database connection in SQL Server
- Save data(retrieve data from Ms Access Database) in SQL Server Database
- Close those database connections
BTW you need to handle many things in these steps like Transaction, concurrency, Duplication, etc., things..
For your information
Connecting ASP.NET to Access and SQL Server Database[
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