Set join condition in ON clause : Self join « Table Join « SQL Server / T-SQL Tutorial






2> CREATE TABLE authors(
3>    au_id          varchar(11),
4>    au_lname       varchar(40)       NOT NULL,
5>    au_fname       varchar(20)       NOT NULL,
6>    phone          char(12)          NOT NULL DEFAULT ('UNKNOWN'),
7>    address        varchar(40)           NULL,
8>    city           varchar(20)           NULL,
9>    state          char(2)               NULL,
10>    zip            char(5)               NULL,
11>    contract       bit               NOT NULL
12> )
13> GO
1> insert authors values('1',  'Joe',   'Abra',   '111 111-1111', '6 St.', 'Berkeley',  'CA', '11111', 1)
2> insert authors values('2',  'Jack',  'Majo',   '222 222-2222', '3 St.', 'Oakland' ,  'CA', '22222', 1)
3> insert authors values('3',  'Pink',  'Cherry', '333 333-3333', '5 Ln.', 'Vancouver', 'BC', '33333', 1)
4> insert authors values('4',  'Blue',  'Albert', '444 444-4444', '7 Av.', 'Vancouver', 'BC', '44444', 1)
5> insert authors values('5',  'Red',   'Anne',   '555 555-5555', '6 Av.', 'Regina',    'SK', '55555', 1)
6> insert authors values('6',  'Black', 'Michel', '666 666-6666', '3 Pl.', 'Regina',    'SK', '66666', 1)
7> insert authors values('7',  'White', 'Sylvia', '777 777-7777', '1 Pl.', 'Rockville', 'MD', '77777', 1)
8> insert authors values('8',  'Yellow','Heather','888 888-8888', '3 Pu',  'Vacaville', 'CA', '88888', 0)
9> insert authors values('9',  'Gold',  'Dep',    '999 999-9999', '5 Av.', 'Oakland',   'CA', '99999', 0)
10> insert authors values('10', 'Siler', 'Dean',   '000 000-0000', '4 Av.', 'Oakland',   'CA', '00000', 1)
11> GO

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1>
2> CREATE TABLE titles(
3>    title_id       varchar(20),
4>    title          varchar(80)       NOT NULL,
5>    type           char(12)          NOT NULL,
6>    pub_id         char(4)               NULL,
7>    price          money                 NULL,
8>    advance        money                 NULL,
9>    royalty        int                   NULL,
10>    ytd_sales      int                   NULL,
11>    notes          varchar(200)          NULL,
12>    pubdate        datetime          NOT NULL
13> )
14> 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

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1>
2> CREATE TABLE titleauthor(
3>    au_id          varchar(20),
4>    title_id       varchar(20),
5>    au_ord         tinyint               NULL,
6>    royaltyper     int                   NULL
7> )
8> GO
1>
2> insert titleauthor values('1', '2', 1, 60)
3> insert titleauthor values('2', '3', 1, 100)
4> insert titleauthor values('3', '4', 1, 100)
5> insert titleauthor values('4', '5', 1, 100)
6> insert titleauthor values('5', '6', 1, 100)
7> insert titleauthor values('6', '7', 2, 40)
8> insert titleauthor values('7', '8', 1, 100)
9> insert titleauthor values('8', '9', 1, 100)
10> GO

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1>
2>
3>
4> SELECT
5> 'Author'=RTRIM(au_lname) + ', ' + au_fname,
6> 'Title'=title
7> FROM authors AS A JOIN titleauthor AS TA
8>     ON A.au_id=TA.au_id          -- JOIN CONDITION
9> JOIN titles AS T
10>     ON T.title_id=TA.title_id    -- JOIN CONDITION
11> WHERE A.state <> 'CA'
12> ORDER BY 1
13> GO
Author                                                         Title
-------------------------------------------------------------- --------------------------------------------------------------------------------
Black, Michel                                                  Any?
Black, Michel                                                  Any?
Blue, Albert                                                   With
Blue, Albert                                                   With
Pink, Cherry                                                   Prolonged
Pink, Cherry                                                   Prolonged
Red, Anne                                                      Valley
Red, Anne                                                      Valley
White, Sylvia                                                  Fifty
White, Sylvia                                                  Fifty

(10 rows affected)
1>
2> drop table authors;
3> drop table titles;
5> GO

1>








4.7.Self join
4.7.1.A self join is really an inner or outer join on the same table.
4.7.2.A self-join that returns Bankers from cities in common with other Bankers
4.7.3.Set join condition in ON clause