Three-Table Join : Introduction « Select Query « MySQL Tutorial

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1.Introduction
2.Select Query
3.Database
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5.Table Join
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8.Logic Operator
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10.Data Types
11.Procedure Function
12.Cursor
13.Trigger
14.Date Time Functions
15.Comparison Functions Operators
16.Aggregate Functions
17.Cast Functions Operators
18.Control Flow Functions
19.Encryption Compression Functions
20.Information Functions
21.Math Numeric Functions
22.Miscellaneous Functions
23.String Functions
24.Regular Expressions
25.Data Dictionary
26.MySQL Utilities
27.Privilege
MySQL Tutorial » Select Query » Introduction 
2.1.9.Three-Table Join
mysql>
mysql>
mysql> CREATE TABLE Books(
    ->    BookID SMALLINT NOT NULL PRIMARY KEY,
    ->    BookTitle VARCHAR(60NOT NULL,
    ->    Copyright YEAR NOT NULL
    -> )
    -> ENGINE=INNODB;
Query OK, rows affected (0.03 sec)

mysql>
mysql>
mysql> INSERT INTO Books VALUES (12786'Java',           1934),
    ->                          (13331'MySQL',          1919),
    ->                          (14356'PHP',            1966),
    ->                          (15729'PERL',           1932),
    ->                          (16284'Oracle',         1996),
    ->                          (17695'Pl/SQL',         1980),
    ->                          (19264'JavaScript',     1992),
    ->                          (19354'www.java2s.com', 1993);
Query OK, rows affected (0.03 sec)
Records: 8  Duplicates: 0  Warnings: 0

mysql>
mysql>
mysql> CREATE TABLE Authors(
    ->    AuthID SMALLINT NOT NULL PRIMARY KEY,
    ->    AuthFN VARCHAR(20),
    ->    AuthMN VARCHAR(20),
    ->    AuthLN VARCHAR(20)
    -> )
    -> ENGINE=INNODB;
Query OK, rows affected (0.06 sec)

mysql>
mysql>
mysql> INSERT INTO Authors VALUES (1006'H''S.', 'T'),
    ->                            (1007'J''C',  'O'),
    ->                            (1008'B', NULL, 'E'),
    ->                            (1009'R''M',  'R'),
    ->                            (1010'J''K',  'T'),
    ->                            (1011'J''G.', 'N'),
    ->                            (1012'A', NULL, 'P'),
    ->                            (1013'A', NULL, 'W'),
    ->                            (1014'N', NULL, 'A');
Query OK, rows affected (0.03 sec)
Records: 9  Duplicates: 0  Warnings: 0

mysql>
mysql>
mysql> CREATE TABLE AuthorBook(
    ->    AuthID SMALLINT NOT NULL,
    ->    BookID SMALLINT NOT NULL,
    ->    PRIMARY KEY (AuthID, BookID),
    ->    FOREIGN KEY (AuthIDREFERENCES Authors (AuthID),
    ->    FOREIGN KEY (BookIDREFERENCES Books (BookID)
    -> )
    -> ENGINE=INNODB;
Query OK, rows affected (0.03 sec)

mysql>
mysql>
mysql> INSERT INTO AuthorBook VALUES (100614356),
    ->                               (100815729),
    ->                               (100912786),
    ->                               (101017695),
    ->                               (101115729),
    ->                               (101219264),
    ->                               (101219354),
    ->                               (101416284);
Query OK, rows affected (0.05 sec)
Records: 8  Duplicates: 0  Warnings: 0

mysql>
mysql>
mysql> select from Authors;
+--------+--------+--------+--------+
| AuthID | AuthFN | AuthMN | AuthLN |
+--------+--------+--------+--------+
|   1006 | H      | S.     | T      |
|   1007 | J      | C      | O      |
|   1008 | B      | NULL   | E      |
|   1009 | R      | M      | R      |
|   1010 | J      | K      | T      |
|   1011 | J      | G.     | N      |
|   1012 | A      | NULL   | P      |
|   1013 | A      | NULL   | W      |
|   1014 | N      | NULL   | A      |
+--------+--------+--------+--------+
rows in set (0.00 sec)

mysql> select from Books;
+--------+----------------+-----------+
| BookID | BookTitle      | Copyright |
+--------+----------------+-----------+
|  12786 | Java           |      1934 |
|  13331 | MySQL          |      1919 |
|  14356 | PHP            |      1966 |
|  15729 | PERL           |      1932 |
|  16284 | Oracle         |      1996 |
|  17695 | Pl/SQL         |      1980 |
|  19264 | JavaScript     |      1992 |
|  19354 | www.java2s.com |      1993 |
+--------+----------------+-----------+
rows in set (0.00 sec)

mysql> select from AuthorBook;
+--------+--------+
| AuthID | BookID |
+--------+--------+
|   1009 |  12786 |
|   1006 |  14356 |
|   1008 |  15729 |
|   1011 |  15729 |
|   1014 |  16284 |
|   1010 |  17695 |
|   1012 |  19264 |
|   1012 |  19354 |
+--------+--------+
rows in set (0.00 sec)

mysql>
mysql> SELECT BookTitle, Copyright, CONCAT_WS(' ', AuthFN, AuthMN, AuthLNAS Author
    -> FROM Books JOIN AuthorBook USING (BookID)
    ->    JOIN Authors USING (AuthID)
    -> WHERE Copyright<1980
    -> ORDER BY BookTitle;
+-----------+-----------+--------+
| BookTitle | Copyright | Author |
+-----------+-----------+--------+
| Java      |      1934 | R M R  |
| PERL      |      1932 | B E    |
| PERL      |      1932 | J G. N |
| PHP       |      1966 | H S. T |
+-----------+-----------+--------+
rows in set (0.00 sec)

mysql>
mysql> drop table AuthorBook;
Query OK, rows affected (0.01 sec)

mysql> drop table Books;
Query OK, rows affected (0.05 sec)

mysql> drop table Authors;
Query OK, rows affected (0.06 sec)
2.1.Introduction
2.1.1.The SELECT statement is used to pull information from a table
2.1.2.The basic SELECT statement syntax
2.1.3.Conditions can be combined to achieve better filtering of results
2.1.4.Hierarchy of Conditions
2.1.5.You can combine conditions
2.1.6.Selecting Particular Columns
2.1.7.To sort a result, use an ORDER BY clause
2.1.8.Use String function in select statement
2.1.9.Three-Table Join
2.1.10.Join a many-to-many map table
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