LEFT OUTER JOIN Demo
postgres=#
postgres=#
postgres=#
postgres=# CREATE TABLE "books" (
postgres(# "id" integer NOT NULL,
postgres(# "title" text NOT NULL,
postgres(# "author_id" integer,
postgres(# "subject_id" integer,
postgres(# Constraint "books_id_pkey" Primary Key ("id")
postgres(# );
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "books_id_pkey" for table "books"
CREATE TABLE
postgres=#
postgres=#
postgres=# insert into books values (7808, 'Java', 4156, 9);
INSERT 0 1
postgres=# insert into books values (4513, 'Javascript', 1866, 15);
INSERT 0 1
postgres=# insert into books values (4267, 'C#', 2001, 15);
INSERT 0 1
postgres=# insert into books values (1608, 'Oracle', 1809, 2);
INSERT 0 1
postgres=# insert into books values (1590, 'Sql Server', 1809, 2);
INSERT 0 1
postgres=# insert into books values (25908, 'Postgre SQL', 15990, 2);
INSERT 0 1
postgres=# insert into books values (1501, 'Python', 2031, 2);
INSERT 0 1
postgres=# insert into books values (190, 'Java by API', 16, 6);
INSERT 0 1
postgres=# insert into books values (1234, '2D', 25041, 3);
INSERT 0 1
postgres=# insert into books values (2038, 'C', 1644, 0);
INSERT 0 1
postgres=# insert into books values (156, 'C++', 115, 9);
INSERT 0 1
postgres=# insert into books values (41473, 'Programming Python', 7805, 4);
INSERT 0 1
postgres=# insert into books values (41477, 'Learning Python', 7805, 4);
INSERT 0 1
postgres=# insert into books values (41478, 'Perl Cookbook', 7806, 4);
INSERT 0 1
postgres=# insert into books values (41472, 'Practical PostgreSQL', 1212, 4);
INSERT 0 1
postgres=#
postgres=# select * from books;
id | title | author_id | subject_id
-------+----------------------+-----------+------------
7808 | Java | 4156 | 9
4513 | Javascript | 1866 | 15
4267 | C# | 2001 | 15
1608 | Oracle | 1809 | 2
1590 | Sql Server | 1809 | 2
25908 | Postgre SQL | 15990 | 2
1501 | Python | 2031 | 2
190 | Java by API | 16 | 6
1234 | 2D | 25041 | 3
2038 | C | 1644 | 0
156 | C++ | 115 | 9
41473 | Programming Python | 7805 | 4
41477 | Learning Python | 7805 | 4
41478 | Perl Cookbook | 7806 | 4
41472 | Practical PostgreSQL | 1212 | 4
(15 rows)
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(# CONSTRAINT "integrity" CHECK (((book_id NOTNULL) AND (edition NOTNULL))),
postgres(# Constraint "pkey" Primary Key ("isbn")
postgres(# );
NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "pkey" for table "editions"
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=# SELECT title, isbn
postgres-# FROM books LEFT OUTER JOIN editions
postgres-# ON (books.id = editions.book_id);
title | isbn
----------------------+------------
C++ | 0929605942
C++ | 1885418035
Java by API | 0760720002
2D | 0679803335
Python | 0694003611
Sql Server | 0394800753
Oracle | 039480001X
Oracle | 0394900014
C | 0823015505
C# | 0451457994
C# | 0451198492
Javascript | 044100590X
Javascript | 0441172717
Java | 0451160916
Java | 0385121679
Postgre SQL | 0590445065
Practical PostgreSQL |
Programming Python | 0596000855
Learning Python |
Perl Cookbook |
(20 rows)
postgres=#
postgres=#
postgres=# drop table editions cascade;
DROP TABLE
postgres=# drop table books cascade;
DROP TABLE
postgres=#
postgres=#