PostgreSQL/Aggregate Functions/Min

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Use min function in table join

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postgres=# postgres=# postgres=# CREATE TABLE "editions" ( postgres(# "isbn" text NOT NULL, postgres(# "book_id" integer, postgres(# "edition" integer, postgres(# "publisher_id" integer, postgres(# "publication" date, postgres(# "type" character(1) postgres(# ); CREATE TABLE postgres=# postgres=# insert into editions values("039480001X", 1608, 1, 59, "1957-03-01", "h"); INSERT 0 1 postgres=# insert into editions values("0451160916", 7808, 1, 75, "1981-08-01", "p"); INSERT 0 1 postgres=# insert into editions values("0394800753", 1590, 1, 59, "1949-03-01", "p"); INSERT 0 1 postgres=# insert into editions values("0590445065", 25908, 1, 150, "1987-03-01", "p"); INSERT 0 1 postgres=# insert into editions values("0694003611", 1501, 1, 65, "1947-03-04", "p"); INSERT 0 1 postgres=# insert into editions values("0679803335", 1234, 1, 102, "1922-01-01", "p"); INSERT 0 1 postgres=# insert into editions values("0760720002", 190, 1, 91, "1868-01-01", "p"); INSERT 0 1 postgres=# insert into editions values("0394900014", 1608, 1, 59, "1957-01-01", "p"); INSERT 0 1 postgres=# insert into editions values("0385121679", 7808, 2, 75, "1993-10-01", "h"); INSERT 0 1 postgres=# insert into editions values("1885418035", 156, 1, 163, "1995-03-28", "p"); INSERT 0 1 postgres=# insert into editions values("0929605942", 156, 2, 171, "1998-12-01", "p"); INSERT 0 1 postgres=# insert into editions values("0441172717", 4513, 2, 99, "1998-09-01", "p"); INSERT 0 1 postgres=# insert into editions values("044100590X", 4513, 3, 99, "1999-10-01", "h"); INSERT 0 1 postgres=# insert into editions values("0451457994", 4267, 3, 101, "2000-09-12", "p"); INSERT 0 1 postgres=# insert into editions values("0451198492", 4267, 3, 101, "1999-10-01", "h"); INSERT 0 1 postgres=# insert into editions values("0823015505", 2038, 1, 62, "1958-01-01", "p"); INSERT 0 1 postgres=# insert into editions values("0596000855", 41473, 2, 113, "2001-03-01", "p"); INSERT 0 1 postgres=# postgres=# select * from editions;

   isbn    | book_id | edition | publisher_id | publication | type

+---------+---------+--------------+-------------+------
039480001X |    1608 |       1 |           59 | 1957-03-01  | h
0451160916 |    7808 |       1 |           75 | 1981-08-01  | p
0394800753 |    1590 |       1 |           59 | 1949-03-01  | p
0590445065 |   25908 |       1 |          150 | 1987-03-01  | p
0694003611 |    1501 |       1 |           65 | 1947-03-04  | p
0679803335 |    1234 |       1 |          102 | 1922-01-01  | p
0760720002 |     190 |       1 |           91 | 1868-01-01  | p
0394900014 |    1608 |       1 |           59 | 1957-01-01  | p
0385121679 |    7808 |       2 |           75 | 1993-10-01  | h
1885418035 |     156 |       1 |          163 | 1995-03-28  | p
0929605942 |     156 |       2 |          171 | 1998-12-01  | p
0441172717 |    4513 |       2 |           99 | 1998-09-01  | p
044100590X |    4513 |       3 |           99 | 1999-10-01  | h
0451457994 |    4267 |       3 |          101 | 2000-09-12  | p
0451198492 |    4267 |       3 |          101 | 1999-10-01  | h
0823015505 |    2038 |       1 |           62 | 1958-01-01  | p
0596000855 |   41473 |       2 |          113 | 2001-03-01  | p

(17 rows) postgres=# postgres=# postgres=# postgres=# CREATE TABLE "publishers" ( postgres(# "id" integer NOT NULL, postgres(# "name" text, postgres(# "address" text, postgres(# Constraint "publishers_pkey" Primary Key ("id") postgres(# ); NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "publishers_pkey" for table "publishers" CREATE TABLE postgres=# postgres=# postgres=# insert into publishers values(150, "Can Press", "29 Ave. Toronto, ON"); INSERT 0 1 postgres=# insert into publishers values(91, "Henry Inc.", "115 Street New York, NY"); INSERT 0 1 postgres=# insert into publishers values(113, "O Inc.", "101 St, Sebastopol, CA"); INSERT 0 1 postgres=# insert into publishers values(62, "W Pubs", "1515, New York"); INSERT 0 1 postgres=# insert into publishers values(105, "N Press", "19 W, New York"); INSERT 0 1 postgres=# insert into publishers values(99, "A Inc", "375 St, New York"); INSERT 0 1 postgres=# insert into publishers values(101, "Z Inc", "375 Ave, New York"); INSERT 0 1 postgres=# insert into publishers values(163, "M Press", "PO Box 1215"); INSERT 0 1 postgres=# insert into publishers values(171, "B", "16 W. 18th St. New York"); INSERT 0 1 postgres=# insert into publishers values(102, "P Inc", "375 Hudson St, New York"); INSERT 0 1 postgres=# insert into publishers values(75, "D Inc", "1540 Broadway, New York"); INSERT 0 1 postgres=# insert into publishers values(65, "H Pubs", "10 E 53rd St, New York"); INSERT 0 1 postgres=# insert into publishers values(59, "R Inc", "1540 Broadway, New York"); INSERT 0 1 postgres=# postgres=# select * from publishers;

id  |    name    |         address

+------------+-------------------------
150 | Can Press  | 29 Ave. Toronto, ON
 91 | Henry Inc. | 115 Street New York, NY
113 | O Inc.     | 101 St, Sebastopol, CA
 62 | W Pubs     | 1515, New York
105 | N Press    | 19 W, New York
 99 | A Inc      | 375 St, New York
101 | Z Inc      | 375 Ave, New York
163 | M Press    | PO Box 1215
171 | B          | 16 W. 18th St. New York
102 | P Inc      | 375 Hudson St, New York
 75 | D Inc      | 1540 Broadway, New York
 65 | H Pubs     | 10 E 53rd St, New York
 59 | R Inc      | 1540 Broadway, New York

(13 rows) postgres=# postgres=# SELECT min(retail), p.name postgres-# FROM (stock NATURAL JOIN editions) postgres-# JOIN publishers AS p (publisher_id) postgres-# USING (publisher_id) postgres-# GROUP BY p.name postgres-# ORDER BY min ASC;

 min  |    name

+------------
16.95 | R Inc
21.95 | A Inc
21.95 | B
22.95 | Z Inc
23.95 | Can Press
23.95 | Henry Inc.
24.95 | M Press
24.95 | P Inc
28.95 | D Inc
28.95 | H Pubs
28.95 | W Pubs

(11 rows) postgres=# postgres=# drop table publishers; DROP TABLE postgres=# drop table editions; DROP TABLE postgres=#

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