SQL/MySQL/Function/Function In Join

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Concatenate string: JOIN tables

   <source lang="sql">

/* mysql> SELECT ArticleTitle, Copyright, CONCAT_WS(" ", AuthorFirstName, AuthorMid dleName, AuthorLastName) AS Author

   -> FROM Articles AS b CROSS JOIN AuthorArticle AS ab ON b.ArticleID=ab.Artic

leID

   ->    CROSS JOIN Authors AS a ON ab.AuthID=a.AuthID
   -> WHERE Copyright<1980
   -> ORDER BY ArticleTitle;

+-------------------+-----------+-------------------+ | ArticleTitle | Copyright | Author | +-------------------+-----------+-------------------+ | Buy a paper | 1932 | James Elk | | Buy a paper | 1932 | Mary G. Lee | | How write a paper | 1934 | Tom M Ride | | Sell a paper | 1966 | Henry S. Thompson | +-------------------+-----------+-------------------+ 4 rows in set (0.02 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, Copyright, CONCAT_WS(" ", AuthorFirstName, AuthorMiddleName, AuthorLastName) AS Author FROM Articles AS b CROSS JOIN AuthorArticle AS ab ON b.ArticleID=ab.ArticleID

  CROSS JOIN Authors AS a ON ab.AuthID=a.AuthID

WHERE Copyright<1980 ORDER BY ArticleTitle;


      </source>
   
  


Using string function, JOIN tables with conditions

   <source lang="sql">

/* mysql> SELECT ArticleTitle, Copyright, CONCAT_WS(" ", AuthorFirstName, AuthorMid dleName, AuthorLastName) AS Author

   -> FROM Articles JOIN AuthorArticle USING (ArticleID)
   ->    JOIN Authors USING (AuthID)
   -> WHERE Copyright<1980
   -> ORDER BY ArticleTitle;

+-------------------+-----------+-------------------+ | ArticleTitle | Copyright | Author | +-------------------+-----------+-------------------+ | Buy a paper | 1932 | James Elk | | Buy a paper | 1932 | Mary G. Lee | | How write a paper | 1934 | Tom M Ride | | Sell a paper | 1966 | Henry S. Thompson | +-------------------+-----------+-------------------+ 4 rows in set (0.01 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, Copyright, CONCAT_WS(" ", AuthorFirstName, AuthorMiddleName, AuthorLastName) AS Author FROM Articles JOIN AuthorArticle USING (ArticleID)

  JOIN Authors USING (AuthID)

WHERE Copyright<1980 ORDER BY ArticleTitle;


      </source>