How can I create custom activities for accessing a SQL database, selecting a procedure and adding SQL parameters to activities?
You can create a custom activity where it can be reused. Use a custom activity library, and have dependency properties to pass the stored procedure name and the connection string. Then you can use a dependency list where you can pass the list of parameters. Alternatively, you can have a collection of custom activities where one is to retrieve parameter information for the stored procedure and pass it to the main workflow and the other custom activity is to execute the stored procedure.