A self-join that returns Bankers from cities in common with other Bankers : Self join « Table Join « SQL Server / T-SQL Tutorial






5>
6> create table Billings (
7>     BankerID           INTEGER,
8>     BillingNumber      INTEGER,
9>     BillingDate        datetime,
10>     BillingTotal       INTEGER,
11>     TermsID            INTEGER,
12>     BillingDueDate     datetime ,
13>     PaymentTotal       INTEGER,
14>     CreditTotal        INTEGER
15>
16> );
17> GO
1>
2> INSERT INTO Billings VALUES (1, 1, '2005-01-22', 165, 1,'2005-04-22',123,321);
3> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (2, 2, '2001-02-21', 165, 1,'2002-02-22',123,321);
2> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (3, 3, '2003-05-02', 165, 1,'2005-04-12',123,321);
2> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (4, 4, '1999-03-12', 165, 1,'2005-04-18',123,321);
2> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (5, 5, '2000-04-23', 165, 1,'2005-04-17',123,321);
2> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (6, 6, '2001-06-14', 165, 1,'2005-04-18',123,321);
2> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (7, 7, '2002-07-15', 165, 1,'2005-04-19',123,321);
2> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (8, 8, '2003-08-16', 165, 1,'2005-04-20',123,321);
2> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (9, 9, '2004-09-17', 165, 1,'2005-04-21',123,321);
2> GO

(1 rows affected)
1> INSERT INTO Billings VALUES (0, 0, '2005-10-18', 165, 1,'2005-04-22',123,321);
2> GO

(1 rows affected)
1>
2>
3>
4> create table Bankers(
5>    BankerID             Integer,
6>    BankerName           VARCHAR(20),
7>    BankerContactLName   VARCHAR(20),
8>    BankerContactFName   VARCHAR(20),
9>    BankerCity           VARCHAR(20),
10>    BankerState          VARCHAR(20),
11>    BankerZipCode        VARCHAR(20),
12>    BankerPhone          VARCHAR(20)
13> )
14> GO
1>
2> insert into Bankers values (1, 'ABC Inc.','Joe','Smith','Vancouver','BC','11111','111-111-1111');
3> GO

(1 rows affected)
1> insert into Bankers values (2, 'DEF Inc.','Red','Rice', 'New York', 'DE','22222','222-222-2222');
2> GO

(1 rows affected)
1> insert into Bankers values (3, 'HJI Inc.','Kit','Cat',  'Paris',    'CA','33333','333-333-3333');
2> GO

(1 rows affected)
1> insert into Bankers values (4, 'QWE Inc.','Git','Black','Regina',   'ER','44444','444-444-4444');
2> GO

(1 rows affected)
1> insert into Bankers values (5, 'RTY Inc.','Wil','Lee',  'Toronto',  'YU','55555','555-555-5555');
2> GO

(1 rows affected)
1> insert into Bankers values (6, 'YUI Inc.','Ted','Larry','Calgary',  'TY','66666','666-666-6666');
2> GO

(1 rows affected)
1> insert into Bankers values (7, 'OIP Inc.','Yam','Act',  'San Franc','FG','77777','777-777-7777');
2> GO

(1 rows affected)
1> insert into Bankers values (8, 'SAD Inc.','Hit','Eat',  'Orland',   'PO','88888','888-888-8888');
2> GO

(1 rows affected)
1> insert into Bankers values (9, 'DFG Inc.','Sad','Lee',  'Wisler',   'PL','99999','999-999-9999');
2> GO

(1 rows affected)
1> insert into Bankers values (0, 'GHJ Inc.','Bit','Lee',  'Ticker',   'MN','00000','000-000-0000');
2> GO

(1 rows affected)
1>
2>
3>
4>
5> SELECT DISTINCT Bankers1.BankerName, Bankers1.BankerCity,
6>     Bankers1.BankerState
7> FROM Bankers AS Bankers1 JOIN Bankers AS Bankers2
8>     ON (Bankers1.BankerCity = Bankers2.BankerCity) AND
9>        (Bankers1.BankerState = Bankers2.BankerState) AND
10>        (Bankers1.BankerID <> Bankers2.BankerID)
11> ORDER BY Bankers1.BankerState, Bankers1.BankerCity
12> GO
BankerName           BankerCity           BankerState
-------------------- -------------------- --------------------

(0 rows affected)
1>
2> drop table Bankers;
3> drop table Billings;
4> 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