UPDATE scores AS sc
SET score = CASE WHEN score+5 >100 THEN 100 ELSE score+5 END 

FROM students AS st
WHERE sc.student_code = st.student_code -- WHERE句に結合条件を指定
    AND student_name IN ('佐藤 幸平','山田 康介');

--UPDATE scores AS sc
--SET score = CASE WHEN score >100 THEN 100 ELSE score END 
--FROM students AS st
--WHERE sc.student_code = st.student_code -- WHERE句に結合条件を指定
  --  AND student_name IN ('佐藤 幸平','山田 康介');
    
SELECT * FROM scores
 WHERE student_code='A00016' or student_code='A00095';