UPDATING in database

You don't need to write code to retrieve records when the data is bound to the form; the framework does it for you.

There are many useful articles in this web site; have a look around. For example my article Database Table Update in a DataGridView without Writing Code introduces how to get Visual Studio to generate most of the program for you. Using that technique, you can generate the form with the grid, then change the type of controls for the data source, then geneate the form for a single record/row. An alternative would be to put both in one form.