I have a web page with some data about the users. Recently, I made a complete change and start developing a new portal and of course a new DB structure. My question : What is the best way to migrate my data from my old DB to my new DB ? My old DB, and my new DB have similar but different structures, both are in SQL SERVER 2008 R2. Thanks.
It depends on how different the various tables are. Without knowing how different the tables are between the databases, I would probably expect a combination of scripts and data compare-import tools such as Red Gate's Data Compare tool.
Using Red Gate's Data Compare, you can work around minor differences in table structures.
For splitting tables or significant changes within a table, you may be better off writing an import script from a local copy of your old database or a live connection to the old database.