SQL/MySQL/Join/Function In Join — различия между версиями

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Версия 13:46, 26 мая 2010

Concatenate string: JOIN tables

/*
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;



Using string function, JOIN tables with conditions

/*
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;