-- from:
-- https://github.com/duckdb/duckdb/blob/74687ec572e9e6ccf34f9b15daa62998b34a3e13/test/sql/subquery/test_neumann.test
CREATE TABLE students(ts TIMESTAMP TIME INDEX, `id` INTEGER, n VARCHAR, major VARCHAR, y INTEGER);

Affected Rows: 0

CREATE TABLE exams(ts TIMESTAMP TIME INDEX, sid INTEGER, course VARCHAR, curriculum VARCHAR, grade INTEGER, y INTEGER);

Affected Rows: 0

INSERT INTO students VALUES (1, 1, 'Mark', 'CS', 2017);

Affected Rows: 1

INSERT INTO students VALUES (2, 2, 'Dirk', 'CS', 2017);

Affected Rows: 1

INSERT INTO exams VALUES (1, 1, 'Database Systems', 'CS', 10, 2015);

Affected Rows: 1

INSERT INTO exams VALUES (2, 1, 'Graphics', 'CS', 9, 2016);

Affected Rows: 1

INSERT INTO exams VALUES (3, 2, 'Database Systems', 'CS', 7, 2015);

Affected Rows: 1

INSERT INTO exams VALUES (4, 2, 'Graphics', 'CS', 7, 2016);

Affected Rows: 1

SELECT s.n, e.course, e.grade FROM students s, exams e WHERE s.`id`=e.sid AND e.grade=(SELECT MAX(e2.grade) FROM exams e2 WHERE s.`id`=e2.sid) ORDER BY n, course;

+------+------------------+-------+
| n    | course           | grade |
+------+------------------+-------+
| Dirk | Database Systems | 7     |
| Dirk | Graphics         | 7     |
| Mark | Database Systems | 10    |
+------+------------------+-------+

-- skipped, unsupported feature: correlated column in predicate, see also:
-- https://github.com/GreptimeTeam/greptimedb/issues/5012
-- SELECT s.n, e.course, e.grade FROM students s, exams e WHERE s.`id`=e.sid AND (s.major = 'CS' OR s.major = 'Games Eng') AND e.grade <= (SELECT AVG(e2.grade) - 1 FROM exams e2 WHERE s.`id`=e2.sid OR (e2.curriculum=s.major AND s.y>=e2.y)) ORDER BY n, course;
-- skipped, unsupported feature: exists, see also:
-- https://github.com/GreptimeTeam/greptimedb/issues/5012
-- SELECT n, major FROM students s WHERE EXISTS(SELECT * FROM exams e WHERE e.sid=s.`id` AND grade=10) OR s.n='Dirk' ORDER BY n;
DROP TABLE students;

Affected Rows: 0

DROP TABLE exams;

Affected Rows: 0