SQL/MySQL/Join/Inner Join

Материал из SQL эксперт
Перейти к: навигация, поиск

INNER JOIN in MySQL

   <source lang="sql">

/* mysql> SELECT ArticleTitle, AuthID FROM Articles INNER JOIN AuthorArticle; +-------------------+--------+ | ArticleTitle | AuthID | +-------------------+--------+ | How write a paper | 1006 | | Publish a paper | 1006 | | Sell a paper | 1006 | | Buy a paper | 1006 | | Conferences | 1006 | | Journal | 1006 | | Information | 1006 | | AI | 1006 | | How write a paper | 1008 | | Publish a paper | 1008 | | Sell a paper | 1008 | | Buy a paper | 1008 | | Conferences | 1008 | | Journal | 1008 | | Information | 1008 | | AI | 1008 | | How write a paper | 1009 | | Publish a paper | 1009 | | Sell a paper | 1009 | | Buy a paper | 1009 | | Conferences | 1009 | | Journal | 1009 | | Information | 1009 | | AI | 1009 | | How write a paper | 1010 | | Publish a paper | 1010 | | Sell a paper | 1010 | | Buy a paper | 1010 | | Conferences | 1010 | | Journal | 1010 | | Information | 1010 | | AI | 1010 | | How write a paper | 1011 | | Publish a paper | 1011 | | Sell a paper | 1011 | | Buy a paper | 1011 | | Conferences | 1011 | | Journal | 1011 | | Information | 1011 | | AI | 1011 | | How write a paper | 1012 | | Publish a paper | 1012 | | Sell a paper | 1012 | | Buy a paper | 1012 | | Conferences | 1012 | | Journal | 1012 | | Information | 1012 | | AI | 1012 | | How write a paper | 1012 | | Publish a paper | 1012 | | Sell a paper | 1012 | | Buy a paper | 1012 | | Conferences | 1012 | | Journal | 1012 | | Information | 1012 | | AI | 1012 | | How write a paper | 1014 | | Publish a paper | 1014 | | Sell a paper | 1014 | | Buy a paper | 1014 | | Conferences | 1014 | | Journal | 1014 | | Information | 1014 | | AI | 1014 | +-------------------+--------+ 64 rows in set (0.19 sec)

  • /

Drop table Articles; Drop table Authors; Drop table AuthorArticle;

CREATE TABLE Articles (

  ArticleID SMALLINT NOT NULL PRIMARY KEY,
  ArticleTitle VARCHAR(60) NOT NULL,
  Copyright YEAR NOT NULL

) ENGINE=INNODB;

INSERT INTO Articles VALUES (12786, "How write a paper", 1934),

                           (13331, "Publish a paper", 1919),
                           (14356, "Sell a paper", 1966),
                           (15729, "Buy a paper", 1932),
                           (16284, "Conferences", 1996),
                           (17695, "Journal", 1980),
                           (19264, "Information", 1992),
                           (19354, "AI", 1993);

CREATE TABLE Authors (

  AuthID SMALLINT NOT NULL PRIMARY KEY,
  AuthorFirstName VARCHAR(20),
  AuthorMiddleName VARCHAR(20),
  AuthorLastName VARCHAR(20)

) ENGINE=INNODB;

INSERT INTO Authors VALUES (1006, "Henry", "S.", "Thompson"),

                          (1007, "Jason", "Carol", "Oak"),
                          (1008, "James", NULL, "Elk"),
                          (1009, "Tom", "M", "Ride"),
                          (1010, "Jack", "K", "Ken"),
                          (1011, "Mary", "G.", "Lee"),
                          (1012, "Annie", NULL, "Peng"),
                          (1013, "Alan", NULL, "Wang"),
                          (1014, "Nelson", NULL, "Yin");

CREATE TABLE AuthorArticle (

  AuthID SMALLINT NOT NULL,
  ArticleID SMALLINT NOT NULL,
  PRIMARY KEY (AuthID, ArticleID),
  FOREIGN KEY (AuthID) REFERENCES Authors (AuthID),
  FOREIGN KEY (ArticleID) REFERENCES Articles (ArticleID)

) ENGINE=INNODB;

INSERT INTO AuthorArticle VALUES (1006, 14356),

                             (1008, 15729), 
                             (1009, 12786), 
                             (1010, 17695),
                             (1011, 15729), 
                             (1012, 19264), 
                             (1012, 19354), 
                             (1014, 16284);
 

SELECT ArticleTitle, AuthID FROM Articles INNER JOIN AuthorArticle;

      </source>