グループで構文エラーが発生するのはなぜですか？

Question

次のクエリを作成しましたが、実行するとGROUP BY句で構文エラーが発生しますが、PostgreSQLを削除すると、t.bsnをGROUP BY句に追加する必要があるというエラーが表示されます。このエラーを修正するにはどうすればよいですか？

SELECT t.bsn 
FROM teachers t, designes d, students s, course c, teaches lg 
WHERE c.course_follower = s.class AND t.bsn = lg.bsn AND d.course_code = c.course_code AND d.bsn = t.bsn AND s.class = lg.class 
HAVING t.salary = (2000 + (t.scale * 200) + ((t.scale - 10) * 300) + (100 * (COUNT(d.course_code) * (1.0 + (0.1 * COUNT(s.student_id)))) + (50 * c.amount_of_assignments))) 
GROUP BY t.bsn; 

Answer 1

SQL標準によるとHAVING句はGROUP BY AFTER を来る必要があります。あなたの前です。

あなたのコード：期待

SELECT 
     t.bsn 
FROM 
     teachers t, designes d, students s, course c, teaches lg 
WHERE 
     c.course_follower = s.class AND 
     t.bsn = lg.bsn AND 
     d.course_code = c.course_code AND 
     d.bsn = t.bsn AND 
     s.class = lg.class 
HAVING 
     t.salary = (2000 + (t.scale * 200) + ((t.scale - 10) * 300) + (100 * (COUNT(d.course_code) * (1.0 + (0.1 * COUNT(s.student_id)))) + (50 * c.amount_of_assignments))) 
GROUP BY 
     t.bsn; 

：

SELECT 
     t.bsn 
FROM 
     teachers t, designes d, students s, course c, teaches lg 
WHERE 
     c.course_follower = s.class AND 
     t.bsn = lg.bsn AND 
     d.course_code = c.course_code AND 
     d.bsn = t.bsn AND 
     s.class = lg.class 
GROUP BY 
     t.bsn 
HAVING 
     t.salary = (2000 + (t.scale * 200) + ((t.scale - 10) * 300) + (100 * (COUNT(d.course_code) * (1.0 + (0.1 * COUNT(s.student_id)))) + (50 * c.amount_of_assignments))); 

汎用SQL例 - http://www.w3schools.com/sql/sql_having.asp

PostgreSQLのSQL例 - https://www.postgresql.org/docs/current/static/tutorial-agg.html