A causa di più tag con oracle , ho ignorato il tag mysql ( di uno di cui dovresti sbarazzarti, ad esempio, decidi quale DBMS stai usando, tra l'altro ho già rimosso quello irrilevante oracle-sqldeveloper ).
Sembra che tu abbia bisogno di una tale dichiarazione selettiva ( preferisci usare il moderno ANSI-92 JOIN sintassi, facilmente gestibile e comprensibile ) con ordinamento decrescente sum e contributo di row_number funziona come :
SELECT Name, Sum_Takings
FROM
(
SELECT f.Name, sum(p.Takings) Sum_Takings,
row_number() over (ORDER BY sum(p.Takings)) as rn
FROM Film f
LEFT JOIN Cinema c ON f.Cinema_ID = c.ID
LEFT JOIN Performance p ON f.ID = p.id_film
GROUP BY f.Name
)
WHERE rn = 1;
con aggiunto DDL dichiarazione come nella seguente :
SQL> CREATE TABLE Cinema (
2 ID integer PRIMARY KEY NOT NULL,
3 Title varchar2(100) NOT NULL
4 );
Table created
SQL> CREATE TABLE Film (
2 ID integer PRIMARY KEY NOT NULL,
3 Name varchar2(100) NOT NULL,
4 Cinema_ID integer
5 CONSTRAINT fk_Cinema_ID REFERENCES Cinema(ID)
6 );
Table created
SQL> CREATE TABLE Performance (
2 ID integer PRIMARY KEY NOT NULL,
3 ID_Film integer
4 CONSTRAINT fk_Film_ID REFERENCES Film(ID),
5 Takings integer
6 );
Table created
SQL> INSERT ALL
2 INTO Cinema(ID,Title) VALUES(1,'NiteHawk')
3 INTO Cinema(ID,Title) VALUES(2,'Symphony Space')
4 INTO Cinema(ID,Title) VALUES(3,'The Ziegfeld')
5 INTO Cinema(ID,Title) VALUES(4,'Cinema Village')
6 SELECT * FROM dual;
4 rows inserted
SQL> INSERT ALL
2 INTO Film(ID,Name,Cinema_ID) VALUES(1,'Citizen Kane',1)
3 INTO Film(ID,Name,Cinema_ID) VALUES(2,'Titanic',2)
4 INTO Film(ID,Name,Cinema_ID) VALUES(3,'Brave Heart',4)
5 INTO Film(ID,Name,Cinema_ID) VALUES(4,'Dumb and Dummer',3)
6 INTO Film(ID,Name,Cinema_ID) VALUES(5,'How To Train Your Dragon',2)
7 INTO Film(ID,Name,Cinema_ID) VALUES(6,'Beetle Juice',3)
8 SELECT * FROM dual;
6 rows inserted
SQL> INSERT ALL
2 INTO Performance VALUES(1,1,15)
3 INTO Performance VALUES(2,1,4)
4 INTO Performance VALUES(3,2,10)
5 INTO Performance VALUES(4,3,1)
6 INTO Performance VALUES(5,4,5)
7 INTO Performance VALUES(6,3,3)
8 INTO Performance VALUES(7,2,7)
9 INTO Performance VALUES(8,5,7)
10 INTO Performance VALUES(9,6,6)
11 SELECT * FROM dual;
9 rows inserted
SQL> commit;
Commit complete
SQL> SELECT Name, Sum_Takings
2 FROM
3 (
4 SELECT f.Name, sum(p.Takings) Sum_Takings,
5 row_number() over (ORDER BY sum(p.Takings)) as rn
6 FROM Film f
7 LEFT JOIN Cinema c ON f.Cinema_ID = c.ID
8 LEFT JOIN Performance p ON f.ID = p.id_film
9 GROUP BY f.Name
10 )
11 WHERE rn = 1
12 ;
NAME SUM_TAKINGS
--------------------------------------------------------------------- -----------
Brave Heart 4
