Answers for "explanation for update from join"

update with join

UPDATE
        first_table ft
        JOIN second_table st ON st.some_id = ft.some_id
        JOIN third_table tt  ON tt.some_id = st.some_id
        .....
    SET
        ft.some_column = some_value
    WHERE ft.some_column = 123456 AND st.some_column = 123456

SQL update with join

UPDATE D
SET D.Name = 'Computer Science and Engineering'
FROM Department D
INNER JOIN Student S ON D.Id = S.DepartmentId