update scores as sc
set score = 100
from students as st
where sc.score >= 95
    and (st.student_name = '佐藤 幸平' or st.student_name = '山田 康介');

update scores as sc
set score = (score + 5)
from students as st
where sc.score < 95
    and (st.student_name = '佐藤 幸平' or st.student_name = '山田 康介');
    
-- select * 
-- from scores as sc
--     inner join students as st
--     on sc.student_code = st.student_code
-- where st.student_name = '佐藤 幸平' or st.student_name = '山田 康介'