PostgreSQL/Table Joins/Outter Join

Inner joins versus outer joins

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=#
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=# -- Inner joins versus outer joins
postgres=#
postgres=# SELECT title, isbn
postgres-#         FROM books INNER JOIN editions
postgres-#         ON (books.id = editions.book_id);
       title        |    isbn
--------------------+------------
 Oracle             | 039480001X
 Java               | 0451160916
 Sql Server         | 0394800753
 Postgre SQL        | 0590445065
 Python             | 0694003611
 2D                 | 0679803335
 Java by API        | 0760720002
 Oracle             | 0394900014
 Java               | 0385121679
 C++                | 1885418035
 C++                | 0929605942
 Javascript         | 0441172717
 Javascript         | 044100590X
 C#                 | 0451457994
 C#                 | 0451198492
 C                  | 0823015505
 Programming Python | 0596000855
(17 rows)
postgres=#
postgres=#
postgres=# drop table books cascade;
DROP TABLE
postgres=# drop table editions cascade;
DROP TABLE
postgres=#
postgres=#