PostgreSQL/Database/USING

The NATURAL and USING clauses

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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=# CREATE TABLE "authors" ( postgres(# "id" integer NOT NULL, postgres(# "last_name" text, postgres(# "first_name" text, postgres(# Constraint "authors_pkey" Primary Key ("id") postgres(# ); NOTICE: CREATE TABLE / PRIMARY KEY will create implicit index "authors_pkey" for table "authors" CREATE TABLE postgres=# postgres=# postgres=# insert into authors values (1111, "Martin", "Jason"); INSERT 0 1 postgres=# insert into authors values (1212, "Worsley", "Robert"); INSERT 0 1 postgres=# insert into authors values (15990, "Mathews", "John"); INSERT 0 1 postgres=# insert into authors values (25041, "Smith", "Williams"); INSERT 0 1 postgres=# insert into authors values (16, "Alcott", "May"); INSERT 0 1 postgres=# insert into authors values (4156, "King", "Stephen"); INSERT 0 1 postgres=# insert into authors values (1866, "Herbert", "Margaret"); INSERT 0 1 postgres=# insert into authors values (1644, "Hogarth", "Celia"); INSERT 0 1 postgres=# insert into authors values (2031, "Brown", "Wise"); INSERT 0 1 postgres=# insert into authors values (115, "Poe", "Allen"); INSERT 0 1 postgres=# insert into authors values (7805, "Lutz", "Mark"); INSERT 0 1 postgres=# insert into authors values (7806, "Rice", "Tom"); INSERT 0 1 postgres=# insert into authors values (1533, "Black", "Chris"); INSERT 0 1 postgres=# insert into authors values (1717, "Brite", "Linda"); INSERT 0 1 postgres=# insert into authors values (2112, "Larry", "Edward"); INSERT 0 1 postgres=# insert into authors values (2001, "Clarke", "Alison"); INSERT 0 1 postgres=# postgres=# select * from authors;

 id   | last_name | first_name

---

+-----------+------------

 1111 | Martin    | Jason
 1212 | Worsley   | Robert
15990 | Mathews   | John
25041 | Smith     | Williams
   16 | Alcott    | May
 4156 | King      | Stephen
 1866 | Herbert   | Margaret
 1644 | Hogarth   | Celia
 2031 | Brown     | Wise
  115 | Poe       | Allen
 7805 | Lutz      | Mark
 7806 | Rice      | Tom
 1533 | Black     | Chris
 1717 | Brite     | Linda
 2112 | Larry     | Edward
 2001 | Clarke    | Alison

(16 rows) postgres=# postgres=# -- The NATURAL and USING clauses postgres=# postgres=# SELECT title, last_name, first_name postgres-# FROM books INNER JOIN authors AS a (author_id) postgres-# USING (author_id) postgres-# WHERE last_name = "Lutz";

      title        | last_name | first_name

---

+-----------+------------

Programming Python | Lutz      | Mark
Learning Python    | Lutz      | Mark

(2 rows) postgres=# postgres=# SELECT title, last_name, first_name postgres-# FROM books NATURAL INNER JOIN authors AS a (author_id) postgres-# WHERE last_name = "Lutz";

      title        | last_name | first_name

---

+-----------+------------

Programming Python | Lutz      | Mark
Learning Python    | Lutz      | Mark

(2 rows) postgres=# postgres=# postgres=# postgres=# postgres=# postgres=# drop table authors; DROP TABLE postgres=# drop table books; DROP TABLE postgres=# postgres=#

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