Please can you tell me what is the best tool for creating a database from scratch?
If that wasn't the answer you thought you were looking for then you need to understand that you don't choose a database based on tool but rather on the functionality of the database vendor. AFTER you have chosen a database then you look for applications that allow you to manage the database application.
It's all about learning not working! so I want to know the tool which can help me to insert data and retrieve it and more.
is SQL server the tool that can help me? or ADO.NET?? and what is the difference between them??
Just Like Mark wrote, I start with the whiteboard.
When that gets to small I make the model in Oracle SQL Developer Data Modeler [^], which supports Oracle, SQL Server and DB2 out of the box, and you can make your own design rules as well.
And as an extra plus, it supports source control via Subversion.
"The ones who care enough to do it right care too much to compromise."