SQL AVG Заработная плата Рекурсивный запрос

Question

в первом запросе. Я получаю штаты, которые ведут других сотрудников , а во втором я получаю зарплату в штате, которая зарабатывает больше, чем аватар. Но я собираюсь объединить оба, чтобы получить менеджеров, которые зарабатывают более чем в два раза больше зарплаты, чем средняя зарплата сотрудников, которые работают на них.

SELECT c.EmpID,c.name,c.gender,c.salary,c.supervisorFK,c.branchFK,c.position 
FROM  staff c INNER JOIN staff u ON c.EmpID = u.supervisorFk 
GROUP BY c.EmpID,c.name,c.gender, c.salary, c.branchFK,c.supervisorFK,c.position 


select name, salary, avg_salary 
from staff 
join (select avg(salary) avg_salary from staff) x 
    on salary > avg_salary 

Я попытался это:

SELECT c.EmpID,c.name,c.gender,c.salary,c.supervisorFK,c.branchFK,c.position 
FROM  staff c INNER JOIN staff u ON c.EmpID = u.supervisorFk 
join (select avg(salary) avg_salary from staff) x 
    on c.salary*2 > avg_salary 
GROUP BY c.EmpID,c.name,c.gender, c.salary, c.branchFK,c.supervisorFK,c.position 

Я получаю 31 хитов, которые не могут быть. Где ошибка? Я не мог найти связанных вопросов. Некоторые из моих запросов я взял из других вопросов. Благодаря

Источник данных:

insert into Staff values (1, 'Robert King'  ,'M', 143000.0,NULL, 'B002', 'Director'); 
insert into Staff values (2, 'Rafael McDonalds' ,'M', 72000.0, 1,'B001', 'Manager'); 
insert into Staff values (3, 'John White'  ,'M', 60000.0, 1,'B003', 'Manager'); 
insert into Staff values (4, 'Susan Brand'  ,'F', 55000.0, 1,'B004', 'Manager'); 
insert into Staff values (5, 'Cathy Brown'  ,'F', 32000.0, 2,'B001', 'Supervisor'); 
insert into Staff values (6, 'Claire Dujeune' ,'F', 79000.0, 1,'B010', 'Manager'); 
insert into Staff values (7, 'Patty Summer'  ,'F', 23000.0, 2,'B001', 'Supervisor'); 
insert into Staff values (8, 'Mary Fleming'  ,'F', 43000.0, 1,'B011', 'Manager'); 
insert into Staff values (10, 'Anne Beech'  ,'F', 26000.0, 5,'B001', 'Assistant'); 
insert into Staff values (12, 'Paul Coplien'  ,'M', 27000.0, 3,'B003', 'Supervisor'); 
insert into Staff values (13, 'David Ford'  ,'M', 41000.0, 1,'B012', 'Manager'); 
insert into Staff values (14, 'Mary Howe'  ,'F', 55000.0, 1,'B005', 'Manager'); 
insert into Staff values (15, 'Julie Lee'  ,'F', 34000.0, 3,'B003', 'Supervisor'); 
insert into Staff values (16, 'Aaron Young'  ,'M', 74000.0, 1,'B013', 'Manager'); 
insert into Staff values (17, 'Albert Thomson' ,'M', 25000.0,13,'B012', 'Supervisor'); 
insert into Staff values (21, 'Alexander Reynolds','M', 37000.0, 5,'B001', 'Assistant'); 
insert into Staff values (18, 'Christine McDonalds','F',38000.0, 4,'B004', 'Supervisor'); 
insert into Staff values (19, 'Elisa Pinkerton' ,'F', 36000.0,16,'B013', 'Supervisor'); 
insert into Staff values (20, 'Eric Montgomery' ,'M', 33000.0, 7,'B001', 'Assistant'); 
insert into Staff values (22, 'Edward Robinson' ,'M', 28000.0, 7,'B001', 'Assistant'); 
insert into Staff values (23, 'Jesse Owens'  ,'M', 34000.0, 4,'B004', 'Supervisor'); 
insert into Staff values (25, 'Johnatan Hunter' ,'M', 45000.0, 1,'B014', 'Manager'); 
insert into Staff values (26, 'Lenita Kennedy' ,'F', 56000.0, 1,'B009', 'Manager'); 
insert into Staff values (27, 'Lisa Miller'  ,'F', 34000.0,25,'B014', 'Supervisor'); 
insert into Staff values (28, 'Lilly Jennings' ,'F', 36000.0,14,'B005', 'Supervisor'); 
insert into Staff values (29, 'Rafaela Johnson' ,'F', 23000.0,12,'B003', 'Assistant'); 
insert into Staff values (32, 'Harry Anderson' ,'M', 40000.0,12,'B003', 'Assistant'); 
insert into Staff values (33, 'George Bailey' ,'M', 73000.0, 1,'B006', 'Manager'); 
insert into Staff values (34, 'Salomon Beckett' ,'M', 46000.0, 1,'B008', 'Manager'); 
insert into Staff values (35, 'Susan Armstrong' ,'F', 28000.0,15,'B003', 'Assistant'); 
insert into Staff values (36, 'Rosa Hemingway' ,'F', 30000.0,15,'B003', 'Assistant'); 
insert into Staff values (37, 'Martha McDonalds' ,'F', 31000.0,15,'B003', 'Assistant'); 
insert into Staff values (38, 'Anna-Isabell Green','F', 32000.0,33,'B006', 'Supervisor'); 
insert into Staff values (39, 'Tina Hall-Becker' ,'F', 34000.0,18,'B004', 'Assistant'); 
insert into Staff values (40, 'Thomas Harrison' ,'M', 42000.0, 1,'B007', 'Manager'); 
insert into Staff values (42, 'Winston Hughes' ,'M', 22000.0,40,'B007', 'Supervisor'); 
insert into Staff values (44, 'Walter Jefferson' ,'M', 23000.0,18,'B004', 'Assistant'); 
insert into Staff values (45, 'Zara Newton'  ,'F', 24000.0,23,'B004', 'Assistant'); 
insert into Staff values (46, 'Nina McDonalds' ,'F', 25000.0,23,'B004', 'Assistant'); 
insert into Staff values (48, 'Carol Moore'  ,'M', 27000.0,40,'B007', 'Supervisor'); 
insert into Staff values (51, 'Alexander Porter' ,'M', 29000.0,17,'B012', 'Assistant'); 
insert into Staff values (52, 'Maria Quasimodo' ,'M', 30000.0,17,'B012', 'Assistant'); 
insert into Staff values (53, 'Bertrand Russel' ,'M', 31000.0,34,'B008', 'Supervisor'); 
insert into Staff values (54, 'Ashley Parker' ,'M', 25500.0,28,'B005', 'Assistant'); 
insert into Staff values (55, 'John Stuart'  ,'M', 23500.0,28,'B005', 'Assistant'); 
insert into Staff values (56, 'Ruth Sanderss' ,'F', 27700.0,19,'B013', 'Assistant'); 
insert into Staff values (57, 'Rafael Smith'  ,'M', 32000.0,19,'B013', 'Assistant'); 
insert into Staff values (58, 'Viola Rutherford' ,'F', 21000.0,27,'B014', 'Assistant'); 
insert into Staff values (59, 'Sammy Churchill' ,'M', 22000.0,27,'B014', 'Assistant'); 
insert into Staff values (60, 'Miriam Thorne' ,'F', 26000.0,27,'B014', 'Assistant'); 
insert into Staff values (61, 'Sally Thatcher' ,'F', 36000.0,34,'B008', 'Supervisor'); 
insert into Staff values (62, 'Larry Escott'  ,'M', 33000.0,26,'B009', 'Supervisor'); 
insert into Staff values (63, 'William Spencer' ,'M', 32000.0, 6,'B010', 'Supervisor'); 
insert into Staff values (64, 'Diana Ashley-Bell','F', 38000.0, 8,'B011', 'Supervisor'); 
insert into Staff values (65, 'Audrey Thorne' ,'F', 25000.0,62,'B009', 'Assistant'); 
insert into Staff values (66, 'Paula Burns'  ,'F', 24000.0,62,'B002', 'Assistant'); 
insert into Staff values (67, 'Amanda Wallis' ,'F', 23000.0,38,'B006', 'Assistant'); 
insert into Staff values (68, 'Patty Stokes'  ,'F', 22000.0,53,'B008', 'Assistant'); 
insert into Staff values (69, 'Holly Fields'  ,'F', 21500.0,53,'B008', 'Assistant'); 
insert into Staff values (70, 'Martha McCulloch' ,'F', 26000.0,61,'B008', 'Assistant'); 
insert into Staff values (71, 'Maurin Best'  ,'F', 22500.0,42,'B007', 'Assistant'); 
insert into Staff values (72, 'Martha McDonalds' ,'F', 23500.0,27,'B014', 'Assistant'); 
insert into Staff values (73, 'Barrigan' ,NULL, 23500.0,27,'B013', 'Assistant'); 
insert into Staff values (47, 'Naomi Campell' ,'F', 26000.0,63,'B010', 'Assistant'); 
insert into Staff values (49, 'Tony McDonalds' ,'M', 28000.0,63,'B010', 'Assistant'); 
insert into Staff values (50, 'Margret McElroy' ,'F', 29000.0,64,'B011', 'Assistant'); 
insert into Staff values (9, 'Carl Maier'  ,'M', 31000.0,64,'B011', 'Assistant'); 

Создать таблицу СОТРУДНИКИ:

CREATE TABLE Staff (
EmpID int, 
name varchar(30) NOT NULL, 
gender char(1) NULL 
CHECK (gender in ('M','F')), 
salary decimal(7,1) NOT NULL, 
supervisorFK int NULL, 
branchFK char(4) NOT NULL, 
position char(10) 
CHECK (position in ('Director','Manager','Supervisor','Assistant')), 

PRIMARY KEY (EmpID) 
); 

Answer 1

Вы выбираете менеджеров, которые зарабатывают более половины среднего.

on c.salary*2 > avg_salary 

Должно быть:

on c.salary/2 > avg_salary 

Или

on c.salary > avg_salary * 2