Mega Code Archive
A self join is really an inner or outer join on the same table
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Selecting books that have the same price.
8>
9> CREATE TABLE titles(
10> title_id varchar(20),
11> title varchar(80) NOT NULL,
12> type char(12) NOT NULL,
13> pub_id char(4) NULL,
14> price money NULL,
15> advance money NULL,
16> royalty int NULL,
17> ytd_sales int NULL,
18> notes varchar(200) NULL,
19> pubdate datetime NOT NULL
20> )
21> GO
1>
2> insert titles values ('1', 'Secrets', 'popular_comp', '1389', $20.00, $8000.00, 10, 4095,'Note 1','06/12/94')
3> insert titles values ('2', 'The', 'business', '1389', $19.99, $5000.00, 10, 4095,'Note 2','06/12/91')
4> insert titles values ('3', 'Emotional', 'psychology', '0736', $7.99, $4000.00, 10, 3336,'Note 3','06/12/91')
5> insert titles values ('4', 'Prolonged', 'psychology', '0736', $19.99, $2000.00, 10, 4072,'Note 4','06/12/91')
6> insert titles values ('5', 'With', 'business', '1389', $11.95, $5000.00, 10, 3876,'Note 5','06/09/91')
7> insert titles values ('6', 'Valley', 'mod_cook', '0877', $19.99, $0.00, 12, 2032,'Note 6','06/09/91')
8> insert titles values ('7', 'Any?', 'trad_cook', '0877', $14.99, $8000.00, 10, 4095,'Note 7','06/12/91')
9> insert titles values ('8', 'Fifty', 'trad_cook', '0877', $11.95, $4000.00, 14, 1509,'Note 8','06/12/91')
10> GO
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
(1 rows affected)
1>
2> SELECT DISTINCT t1.price, t1.title
3> FROM titles t1
4> JOIN titles t2 ON t1.price = t2.price
5> AND t1.title_id <> t2.title_id
6> GO
price title
--------------------- --------------------------------------------------------------------------------
11.9500 Fifty
19.9900 Prolonged
19.9900 The
19.9900 Valley
11.9500 With
(5 rows affected)
1>
2> drop table titles;
3> GO
1>
2>
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