I have a datagridview which is filled with data from db and i need to do this:
when click on a row in datagrid all the fields with data from this row will be in other textbo
On your CellClick event, do int rowIndex = e.RowIndex. From there you can do DataGridViewRow row = DataGridView1.Rows[rowIndex] and access all the cells in row (or better yet, from your underlying DataTable).