MySQL Tutorial/Subquery/Introduction
Содержание
- 1 A scalar subquery can be part of an expression
- 2 A subquery is a SELECT statement within another statement.
- 3 Comparisons Using Subqueries
- 4 Delete with subquery
- 5 Find all rows in a table containing a value that occurs twice in a given column
- 6 Get the Row Holding the Maximum of a Certain Column with sub query in where clause
- 7 NULL Subquery with gradter than (>)
- 8 Subqueries in the FROM clause
- 9 The Rows Holding the Group-wise Maximum of a Certain Field
- 10 The Subquery as Scalar Operand
- 11 Update with subquery
- 12 Using Having to subquery
- 13 Using Join in the subquery
- 14 Using the aggregate function in subquery
A scalar subquery can be part of an expression
<source lang="sql">
mysql> mysql> CREATE TABLE Employee(
-> id int, -> first_name VARCHAR(15), -> last_name VARCHAR(15), -> start_date DATE, -> end_date DATE, -> salary FLOAT(8,2), -> city VARCHAR(10), -> description VARCHAR(15) -> );
Query OK, 0 rows affected (0.03 sec) mysql> mysql> create table job (
-> id int, -> title VARCHAR(20) -> );
Query OK, 0 rows affected (0.05 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values (1,"Jason", "Martin", "19960725", "20060725", 1234.56, "Toronto", "Programmer");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(2,"Alison", "Mathews", "19760321", "19860221", 6661.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(3,"James", "Smith", "19781212", "19900315", 6544.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(4,"Celia", "Rice", "19821024", "19990421", 2344.78, "Vancouver","Manager");
Query OK, 1 row affected (0.02 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(5,"Robert", "Black", "19840115", "19980808", 2334.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(6,"Linda", "Green", "19870730", "19960104", 4322.78,"New York", "Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(7,"David", "Larry", "19901231", "19980212", 7897.78,"New York", "Manager");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(8,"James", "Cat", "19960917", "20020415", 1232.78,"Vancouver", "Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into job (id, title) values (1,"Tester"); Query OK, 1 row affected (0.00 sec) mysql> insert into job (id, title) values (2,"Accountant"); Query OK, 1 row affected (0.00 sec) mysql> insert into job (id, title) values (3,"Developer"); Query OK, 1 row affected (0.00 sec) mysql> insert into job (id, title) values (4,"Coder"); Query OK, 1 row affected (0.00 sec) mysql> insert into job (id, title) values (5,"Director"); Query OK, 1 row affected (0.00 sec) mysql> insert into job (id, title) values (6,"Mediator"); Query OK, 1 row affected (0.00 sec) mysql> insert into job (id, title) values (7,"Proffessor"); Query OK, 1 row affected (0.00 sec) mysql> insert into job (id, title) values (8,"Programmer"); Query OK, 1 row affected (0.00 sec) mysql> insert into job (id, title) values (9,"Developer"); Query OK, 1 row affected (0.00 sec) mysql> mysql> select * from job; +------+------------+ | id | title | +------+------------+ | 1 | Tester | | 2 | Accountant | | 3 | Developer | | 4 | Coder | | 5 | Director | | 6 | Mediator | | 7 | Proffessor | | 8 | Programmer | | 9 | Developer | +------+------------+ 9 rows in set (0.00 sec) mysql> select * from Employee; +------+------------+-----------+------------+------------+---------+-----------+-------------+ | id | first_name | last_name | start_date | end_date | salary | city | description | +------+------------+-----------+------------+------------+---------+-----------+-------------+ | 1 | Jason | Martin | 1996-07-25 | 2006-07-25 | 1234.56 | Toronto | Programmer | | 2 | Alison | Mathews | 1976-03-21 | 1986-02-21 | 6661.78 | Vancouver | Tester | | 3 | James | Smith | 1978-12-12 | 1990-03-15 | 6544.78 | Vancouver | Tester | | 4 | Celia | Rice | 1982-10-24 | 1999-04-21 | 2344.78 | Vancouver | Manager | | 5 | Robert | Black | 1984-01-15 | 1998-08-08 | 2334.78 | Vancouver | Tester | | 6 | Linda | Green | 1987-07-30 | 1996-01-04 | 4322.78 | New York | Tester | | 7 | David | Larry | 1990-12-31 | 1998-02-12 | 7897.78 | New York | Manager | | 8 | James | Cat | 1996-09-17 | 2002-04-15 | 1232.78 | Vancouver | Tester | +------+------------+-----------+------------+------------+---------+-----------+-------------+ 8 rows in set (0.00 sec) mysql> mysql> mysql> mysql> SELECT UPPER((SELECT max(title) FROM job)) FROM employee; +-------------------------------------+ | UPPER((SELECT max(title) FROM job)) | +-------------------------------------+ | TESTER | | TESTER | | TESTER | | TESTER | | TESTER | | TESTER | | TESTER | | TESTER | +-------------------------------------+ 8 rows in set (0.00 sec) mysql> mysql> mysql> mysql> drop table job; Query OK, 0 rows affected (0.00 sec) mysql> drop table Employee; Query OK, 0 rows affected (0.01 sec) mysql> mysql></source>
A subquery is a SELECT statement within another statement.
A subquery must always appear within parentheses.
A subquery"s outer statement must be one of: SELECT, INSERT, UPDATE, DELETE, SET, or DO.
<source lang="sql">
mysql> mysql> CREATE TABLE Employee(
-> id int, -> first_name VARCHAR(15), -> last_name VARCHAR(15), -> start_date DATE, -> end_date DATE, -> salary FLOAT(8,2), -> city VARCHAR(10), -> description VARCHAR(15) -> );
Query OK, 0 rows affected (0.01 sec) mysql> mysql> create table job (
-> id int, -> title VARCHAR(20) -> );
Query OK, 0 rows affected (0.03 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values (1,"Jason", "Martin", "19960725", "20060725", 1234.56, "Toronto", "Programmer");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(2,"Alison", "Mathews", "19760321", "19860221", 6661.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(3,"James", "Smith", "19781212", "19900315", 6544.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(4,"Celia", "Rice", "19821024", "19990421", 2344.78, "Vancouver","Manager");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(5,"Robert", "Black", "19840115", "19980808", 2334.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(6,"Linda", "Green", "19870730", "19960104", 4322.78,"New York", "Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(7,"David", "Larry", "19901231", "19980212", 7897.78,"New York", "Manager");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(8,"James", "Cat", "19960917", "20020415", 1232.78,"Vancouver", "Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into job (id, title) values (1,"Tester"); Query OK, 1 row affected (0.00 sec) mysql> insert into job (id, title) values (2,"Accountant"); Query OK, 1 row affected (0.00 sec) mysql> insert into job (id, title) values (3,"Developer"); Query OK, 1 row affected (0.00 sec) mysql> insert into job (id, title) values (4,"Coder"); Query OK, 1 row affected (0.00 sec) mysql> insert into job (id, title) values (5,"Director"); Query OK, 1 row affected (0.00 sec) mysql> insert into job (id, title) values (6,"Mediator"); Query OK, 1 row affected (0.00 sec) mysql> insert into job (id, title) values (7,"Proffessor"); Query OK, 1 row affected (0.01 sec) mysql> insert into job (id, title) values (8,"Programmer"); Query OK, 1 row affected (0.00 sec) mysql> insert into job (id, title) values (9,"Developer"); Query OK, 1 row affected (0.00 sec) mysql> mysql> select * from job; +------+------------+ | id | title | +------+------------+ | 1 | Tester | | 2 | Accountant | | 3 | Developer | | 4 | Coder | | 5 | Director | | 6 | Mediator | | 7 | Proffessor | | 8 | Programmer | | 9 | Developer | +------+------------+ 9 rows in set (0.00 sec) mysql> select * from Employee; +------+------------+-----------+------------+------------+---------+-----------+-------------+ | id | first_name | last_name | start_date | end_date | salary | city | description | +------+------------+-----------+------------+------------+---------+-----------+-------------+ | 1 | Jason | Martin | 1996-07-25 | 2006-07-25 | 1234.56 | Toronto | Programmer | | 2 | Alison | Mathews | 1976-03-21 | 1986-02-21 | 6661.78 | Vancouver | Tester | | 3 | James | Smith | 1978-12-12 | 1990-03-15 | 6544.78 | Vancouver | Tester | | 4 | Celia | Rice | 1982-10-24 | 1999-04-21 | 2344.78 | Vancouver | Manager | | 5 | Robert | Black | 1984-01-15 | 1998-08-08 | 2334.78 | Vancouver | Tester | | 6 | Linda | Green | 1987-07-30 | 1996-01-04 | 4322.78 | New York | Tester | | 7 | David | Larry | 1990-12-31 | 1998-02-12 | 7897.78 | New York | Manager | | 8 | James | Cat | 1996-09-17 | 2002-04-15 | 1232.78 | Vancouver | Tester | +------+------------+-----------+------------+------------+---------+-----------+-------------+ 8 rows in set (0.00 sec) mysql> mysql> mysql> mysql> SELECT * FROM employee WHERE id = (SELECT max(id) FROM job); Empty set (0.02 sec) mysql> mysql> mysql> mysql> drop table job; Query OK, 0 rows affected (0.00 sec) mysql> drop table Employee; Query OK, 0 rows affected (0.00 sec) mysql> mysql></source>
Comparisons Using Subqueries
The most common use of a subquery is in the form:
non_subquery_operand comparison_operator (subquery)
Where comparison_operator is one of these operators:
<source lang="sql">
= > < >= <= <></source>
Delete with subquery
<source lang="sql">
mysql> mysql> CREATE TABLE Books(
-> BookID SMALLINT NOT NULL PRIMARY KEY, -> BookTitle VARCHAR(60) NOT NULL, -> Copyright YEAR NOT NULL -> ) -> ENGINE=INNODB;
Query OK, 0 rows affected (0.05 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.sqle.ru", 1993);
Query OK, 8 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, 0 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, 9 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 (AuthID) REFERENCES Authors (AuthID), -> FOREIGN KEY (BookID) REFERENCES Books (BookID) -> ) -> ENGINE=INNODB;
Query OK, 0 rows affected (0.06 sec) mysql> mysql> mysql> INSERT INTO AuthorBook VALUES (1006, 14356),
-> (1008, 15729), -> (1009, 12786), -> (1010, 17695), -> (1011, 15729), -> (1012, 19264), -> (1012, 19354), -> (1014, 16284);
Query OK, 8 rows affected (0.03 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 | +--------+--------+--------+--------+ 9 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.sqle.ru | 1993 | +--------+----------------+-----------+ 8 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 | +--------+--------+ 8 rows in set (0.00 sec) mysql> mysql> mysql> DELETE ab, b
-> FROM AuthorBook AS ab, Books AS b -> WHERE ab.BookID=b.BookID -> AND ab.AuthID=(SELECT AuthID FROM Authors WHERE AuthLN="A");
Query OK, 2 rows affected (0.03 sec) 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 | +--------+--------+--------+--------+ 9 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 | | 17695 | Pl/SQL | 1980 | | 19264 | JavaScript | 1992 | | 19354 | www.sqle.ru | 1993 | +--------+----------------+-----------+ 7 rows in set (0.00 sec) mysql> select * from AuthorBook; +--------+--------+ | AuthID | BookID | +--------+--------+ | 1009 | 12786 | | 1006 | 14356 | | 1008 | 15729 | | 1011 | 15729 | | 1010 | 17695 | | 1012 | 19264 | | 1012 | 19354 | +--------+--------+ 7 rows in set (0.00 sec) mysql> mysql> mysql> drop table AuthorBook; Query OK, 0 rows affected (0.03 sec) mysql> drop table Books; Query OK, 0 rows affected (0.06 sec) mysql> drop table Authors; Query OK, 0 rows affected (0.05 sec) mysql> mysql></source>
Find all rows in a table containing a value that occurs twice in a given column
<source lang="sql">
mysql> mysql> mysql> mysql> CREATE TABLE Employee(
-> id int, -> first_name VARCHAR(15), -> last_name VARCHAR(15), -> start_date DATE, -> end_date DATE, -> salary FLOAT(8,2), -> city VARCHAR(10), -> description VARCHAR(15) -> );
Query OK, 0 rows affected (0.03 sec) mysql> mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values (1,"Jason", "Martin", "19960725", "20060725", 1234.56, "Toronto", "Programmer");
Query OK, 1 row affected (0.02 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(2,"Alison", "Mathews", "19760321", "19860221", 6661.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(3,"James", "Smith", "19781212", "19900315", 6544.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(4,"Celia", "Rice", "19821024", "19990421", 2344.78, "Vancouver","Manager");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(5,"Robert", "Black", "19840115", "19980808", 2334.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(6,"Linda", "Green", "19870730", "19960104", 4322.78,"New York", "Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(7,"David", "Larry", "19901231", "19980212", 7897.78,"New York", "Manager");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(8,"James", "Cat", "19960917", "20020415", 1232.78,"Vancouver", "Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> select * from Employee; +------+------------+-----------+------------+------------+---------+-----------+-------------+ | id | first_name | last_name | start_date | end_date | salary | city | description | +------+------------+-----------+------------+------------+---------+-----------+-------------+ | 1 | Jason | Martin | 1996-07-25 | 2006-07-25 | 1234.56 | Toronto | Programmer | | 2 | Alison | Mathews | 1976-03-21 | 1986-02-21 | 6661.78 | Vancouver | Tester | | 3 | James | Smith | 1978-12-12 | 1990-03-15 | 6544.78 | Vancouver | Tester | | 4 | Celia | Rice | 1982-10-24 | 1999-04-21 | 2344.78 | Vancouver | Manager | | 5 | Robert | Black | 1984-01-15 | 1998-08-08 | 2334.78 | Vancouver | Tester | | 6 | Linda | Green | 1987-07-30 | 1996-01-04 | 4322.78 | New York | Tester | | 7 | David | Larry | 1990-12-31 | 1998-02-12 | 7897.78 | New York | Manager | | 8 | James | Cat | 1996-09-17 | 2002-04-15 | 1232.78 | Vancouver | Tester | +------+------------+-----------+------------+------------+---------+-----------+-------------+ 8 rows in set (0.00 sec) mysql> mysql> mysql> mysql> mysql> SELECT * FROM employee AS t
-> WHERE 2 = (SELECT COUNT(*) FROM employee WHERE employee.id = t.id);
Empty set (0.00 sec) mysql> mysql> mysql> mysql> mysql> drop table Employee; Query OK, 0 rows affected (0.01 sec) mysql></source>
Get the Row Holding the Maximum of a Certain Column with sub query in where clause
<source lang="sql">
mysql> mysql> mysql> CREATE TABLE Employee(
-> id int, -> first_name VARCHAR(15), -> last_name VARCHAR(15), -> start_date DATE, -> end_date DATE, -> salary FLOAT(8,2), -> city VARCHAR(10), -> description VARCHAR(15) -> );
Query OK, 0 rows affected (0.05 sec) mysql> mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values (1,"Jason", "Martin", "19960725", "20060725", 1234.56, "Toronto", "Programmer");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(2,"Alison", "Mathews", "19760321", "19860221", 6661.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(3,"James", "Smith", "19781212", "19900315", 6544.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(4,"Celia", "Rice", "19821024", "19990421", 2344.78, "Vancouver","Manager");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(5,"Robert", "Black", "19840115", "19980808", 2334.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(6,"Linda", "Green", "19870730", "19960104", 4322.78,"New York", "Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(7,"David", "Larry", "19901231", "19980212", 7897.78,"New York", "Manager");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(8,"James", "Cat", "19960917", "20020415", 1232.78,"Vancouver", "Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> select * from Employee; +------+------------+-----------+------------+------------+---------+-----------+-------------+ | id | first_name | last_name | start_date | end_date | salary | city | description | +------+------------+-----------+------------+------------+---------+-----------+-------------+ | 1 | Jason | Martin | 1996-07-25 | 2006-07-25 | 1234.56 | Toronto | Programmer | | 2 | Alison | Mathews | 1976-03-21 | 1986-02-21 | 6661.78 | Vancouver | Tester | | 3 | James | Smith | 1978-12-12 | 1990-03-15 | 6544.78 | Vancouver | Tester | | 4 | Celia | Rice | 1982-10-24 | 1999-04-21 | 2344.78 | Vancouver | Manager | | 5 | Robert | Black | 1984-01-15 | 1998-08-08 | 2334.78 | Vancouver | Tester | | 6 | Linda | Green | 1987-07-30 | 1996-01-04 | 4322.78 | New York | Tester | | 7 | David | Larry | 1990-12-31 | 1998-02-12 | 7897.78 | New York | Manager | | 8 | James | Cat | 1996-09-17 | 2002-04-15 | 1232.78 | Vancouver | Tester | +------+------------+-----------+------------+------------+---------+-----------+-------------+ 8 rows in set (0.00 sec) mysql> mysql> mysql> mysql> SELECT id, first_name
-> FROM employee -> WHERE salary=(SELECT MAX(salary) FROM employee);
+------+------------+ | id | first_name | +------+------------+ | 7 | David | +------+------------+ 1 row in set (0.00 sec) mysql> mysql> mysql> mysql> mysql> drop table Employee; Query OK, 0 rows affected (0.00 sec) mysql> mysql></source>
NULL Subquery with gradter than (>)
<source lang="sql">
SELECT * FROM t1 WHERE 1 > (SELECT s1 FROM t2) is NULL when table t2 is empty: SELECT * FROM t1 WHERE 1 > (SELECT s1 FROM t2);</source>
Subqueries in the FROM clause
Subqueries are legal in a SELECT statement"s FROM clause. The actual syntax is:
<source lang="sql">
SELECT ... FROM (subquery) [AS] name ...</source>
The Rows Holding the Group-wise Maximum of a Certain Field
<source lang="sql">
mysql> mysql> mysql> CREATE TABLE Employee(
-> id int, -> first_name VARCHAR(15), -> last_name VARCHAR(15), -> start_date DATE, -> end_date DATE, -> salary FLOAT(8,2), -> city VARCHAR(10), -> description VARCHAR(15) -> );
Query OK, 0 rows affected (0.03 sec) mysql> mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values (1,"Jason", "Martin", "19960725", "20060725", 1234.56, "Toronto", "Programmer");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(2,"Alison", "Mathews", "19760321", "19860221", 6661.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(3,"James", "Smith", "19781212", "19900315", 6544.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(4,"Celia", "Rice", "19821024", "19990421", 2344.78, "Vancouver","Manager");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(5,"Robert", "Black", "19840115", "19980808", 2334.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(6,"Linda", "Green", "19870730", "19960104", 4322.78,"New York", "Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(7,"David", "Larry", "19901231", "19980212", 7897.78,"New York", "Manager");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(8,"James", "Cat", "19960917", "20020415", 1232.78,"Vancouver", "Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> select * from Employee; +------+------------+-----------+------------+------------+---------+-----------+-------------+ | id | first_name | last_name | start_date | end_date | salary | city | description | +------+------------+-----------+------------+------------+---------+-----------+-------------+ | 1 | Jason | Martin | 1996-07-25 | 2006-07-25 | 1234.56 | Toronto | Programmer | | 2 | Alison | Mathews | 1976-03-21 | 1986-02-21 | 6661.78 | Vancouver | Tester | | 3 | James | Smith | 1978-12-12 | 1990-03-15 | 6544.78 | Vancouver | Tester | | 4 | Celia | Rice | 1982-10-24 | 1999-04-21 | 2344.78 | Vancouver | Manager | | 5 | Robert | Black | 1984-01-15 | 1998-08-08 | 2334.78 | Vancouver | Tester | | 6 | Linda | Green | 1987-07-30 | 1996-01-04 | 4322.78 | New York | Tester | | 7 | David | Larry | 1990-12-31 | 1998-02-12 | 7897.78 | New York | Manager | | 8 | James | Cat | 1996-09-17 | 2002-04-15 | 1232.78 | Vancouver | Tester | +------+------------+-----------+------------+------------+---------+-----------+-------------+ 8 rows in set (0.00 sec) mysql> mysql> mysql> mysql> mysql> SELECT id, first_name, salary
-> FROM employee s1 -> WHERE salary=(SELECT MAX(s2.salary) -> FROM employee s2 -> WHERE s1.city = s2.city);
+------+------------+---------+ | id | first_name | salary | +------+------------+---------+ | 1 | Jason | 1234.56 | | 2 | Alison | 6661.78 | | 7 | David | 7897.78 | +------+------------+---------+ 3 rows in set (0.00 sec) mysql> mysql> mysql> mysql> drop table Employee; Query OK, 0 rows affected (0.00 sec) mysql> mysql></source>
The Subquery as Scalar Operand
A scalar subquery returns a single value.
<source lang="sql">
mysql> mysql> mysql> CREATE TABLE Employee(
-> id int, -> first_name VARCHAR(15), -> last_name VARCHAR(15), -> start_date DATE, -> end_date DATE, -> salary FLOAT(8,2), -> city VARCHAR(10), -> description VARCHAR(15) -> );
Query OK, 0 rows affected (0.03 sec) mysql> mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values (1,"Jason", "Martin", "19960725", "20060725", 1234.56, "Toronto", "Programmer");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(2,"Alison", "Mathews", "19760321", "19860221", 6661.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(3,"James", "Smith", "19781212", "19900315", 6544.78, "Vancouver","Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(4,"Celia", "Rice", "19821024", "19990421", 2344.78, "Vancouver","Manager");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(5,"Robert", "Black", "19840115", "19980808", 2334.78, "Vancouver","Tester");
Query OK, 1 row affected (0.01 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(6,"Linda", "Green", "19870730", "19960104", 4322.78,"New York", "Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(7,"David", "Larry", "19901231", "19980212", 7897.78,"New York", "Manager");
Query OK, 1 row affected (0.00 sec) mysql> mysql> insert into Employee(id,first_name, last_name, start_date, end_Date, salary, City, Description)
-> values(8,"James", "Cat", "19960917", "20020415", 1232.78,"Vancouver", "Tester");
Query OK, 1 row affected (0.00 sec) mysql> mysql> select * from Employee; +------+------------+-----------+------------+------------+---------+-----------+-------------+ | id | first_name | last_name | start_date | end_date | salary | city | description | +------+------------+-----------+------------+------------+---------+-----------+-------------+ | 1 | Jason | Martin | 1996-07-25 | 2006-07-25 | 1234.56 | Toronto | Programmer | | 2 | Alison | Mathews | 1976-03-21 | 1986-02-21 | 6661.78 | Vancouver | Tester | | 3 | James | Smith | 1978-12-12 | 1990-03-15 | 6544.78 | Vancouver | Tester | | 4 | Celia | Rice | 1982-10-24 | 1999-04-21 | 2344.78 | Vancouver | Manager | | 5 | Robert | Black | 1984-01-15 | 1998-08-08 | 2334.78 | Vancouver | Tester | | 6 | Linda | Green | 1987-07-30 | 1996-01-04 | 4322.78 | New York | Tester | | 7 | David | Larry | 1990-12-31 | 1998-02-12 | 7897.78 | New York | Manager | | 8 | James | Cat | 1996-09-17 | 2002-04-15 | 1232.78 | Vancouver | Tester | +------+------------+-----------+------------+------------+---------+-----------+-------------+ 8 rows in set (0.00 sec) mysql> mysql> mysql> mysql> mysql> SELECT (SELECT max(id) FROM employee); +--------------------------------+ | (SELECT max(id) FROM employee) | +--------------------------------+ | 8 | +--------------------------------+ 1 row in set (0.00 sec) mysql> mysql> mysql> mysql> mysql> drop table Employee; Query OK, 0 rows affected (0.00 sec) mysql> mysql> mysql></source>
Update with subquery
<source lang="sql">
mysql> mysql> mysql> CREATE TABLE Books(
-> BookID SMALLINT NOT NULL PRIMARY KEY, -> BookTitle VARCHAR(60) NOT NULL, -> Copyright YEAR NOT NULL -> ) -> ENGINE=INNODB;
Query OK, 0 rows affected (0.08 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.sqle.ru", 1993);
Query OK, 8 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, 0 rows affected (0.05 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, 9 rows affected (0.01 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 (AuthID) REFERENCES Authors (AuthID), -> FOREIGN KEY (BookID) REFERENCES Books (BookID) -> ) -> ENGINE=INNODB;
Query OK, 0 rows affected (0.08 sec) mysql> mysql> mysql> INSERT INTO AuthorBook VALUES (1006, 14356),
-> (1008, 15729), -> (1009, 12786), -> (1010, 17695), -> (1011, 15729), -> (1012, 19264), -> (1012, 19354), -> (1014, 16284);
Query OK, 8 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 | +--------+--------+--------+--------+ 9 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.sqle.ru | 1993 | +--------+----------------+-----------+ 8 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 | +--------+--------+ 8 rows in set (0.00 sec) mysql> mysql> UPDATE Books
-> SET BookTitle="Java", Copyright=1957 -> WHERE BookID= -> ( -> SELECT ab.BookID -> FROM Authors AS a, AuthorBook AS ab -> WHERE a.AuthID=ab.AuthID AND a.AuthLN="Watts" -> );
Query OK, 0 rows affected (0.02 sec) mysql> 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.sqle.ru | 1993 | +--------+----------------+-----------+ 8 rows in set (0.00 sec) mysql> mysql> mysql> drop table AuthorBook; Query OK, 0 rows affected (0.01 sec) mysql> drop table Books; Query OK, 0 rows affected (0.05 sec) mysql> drop table Authors; Query OK, 0 rows affected (0.06 sec)</source>
Using Having to subquery
<source lang="sql">
mysql> mysql> CREATE TABLE Books(
-> BookID SMALLINT NOT NULL PRIMARY KEY, -> BookTitle VARCHAR(60) NOT NULL, -> Copyright YEAR NOT NULL -> ) -> ENGINE=INNODB;
Query OK, 0 rows affected (0.05 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.sqle.ru", 1993);
Query OK, 8 rows affected (0.02 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, 0 rows affected (0.05 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, 9 rows affected (0.05 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 (AuthID) REFERENCES Authors (AuthID), -> FOREIGN KEY (BookID) REFERENCES Books (BookID) -> ) -> ENGINE=INNODB;
Query OK, 0 rows affected (0.05 sec) mysql> mysql> mysql> INSERT INTO AuthorBook VALUES (1006, 14356),
-> (1008, 15729), -> (1009, 12786), -> (1010, 17695), -> (1011, 15729), -> (1012, 19264), -> (1012, 19354), -> (1014, 16284);
Query OK, 8 rows affected (0.01 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 | +--------+--------+--------+--------+ 9 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.sqle.ru | 1993 | +--------+----------------+-----------+ 8 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 | +--------+--------+ 8 rows in set (0.00 sec) mysql> mysql> mysql> SELECT BookID FROM AuthorBook WHERE AuthID IN
-> ( -> SELECT AuthID FROM AuthorBook -> GROUP BY AuthID -> HAVING COUNT(*)>1 -> );
+--------+ | BookID | +--------+ | 19264 | | 19354 | +--------+ 2 rows in set (0.00 sec) mysql> mysql> mysql> drop table AuthorBook; Query OK, 0 rows affected (0.05 sec) mysql> drop table Books; Query OK, 0 rows affected (0.03 sec) mysql> drop table Authors; Query OK, 0 rows affected (0.05 sec)</source>
Using Join in the subquery
<source lang="sql">
mysql> mysql> mysql> mysql> CREATE TABLE Books(
-> BookID SMALLINT NOT NULL PRIMARY KEY, -> BookTitle VARCHAR(60) NOT NULL, -> Copyright YEAR NOT NULL -> ) -> ENGINE=INNODB;
Query OK, 0 rows affected (0.05 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.sqle.ru", 1993);
Query OK, 8 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, 0 rows affected (0.05 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, 9 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 (AuthID) REFERENCES Authors (AuthID), -> FOREIGN KEY (BookID) REFERENCES Books (BookID) -> ) -> ENGINE=INNODB;
Query OK, 0 rows affected (0.08 sec) mysql> mysql> mysql> INSERT INTO AuthorBook VALUES (1006, 14356),
-> (1008, 15729), -> (1009, 12786), -> (1010, 17695), -> (1011, 15729), -> (1012, 19264), -> (1012, 19354), -> (1014, 16284);
Query OK, 8 rows affected (0.03 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 | +--------+--------+--------+--------+ 9 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.sqle.ru | 1993 | +--------+----------------+-----------+ 8 rows in set (0.02 sec) mysql> select * from AuthorBook; +--------+--------+ | AuthID | BookID | +--------+--------+ | 1009 | 12786 | | 1006 | 14356 | | 1008 | 15729 | | 1011 | 15729 | | 1014 | 16284 | | 1010 | 17695 | | 1012 | 19264 | | 1012 | 19354 | +--------+--------+ 8 rows in set (0.00 sec) mysql> mysql> SELECT BookTitle, Copyright
-> FROM Books -> WHERE Copyright > ALL -> ( -> SELECT b.copyright -> FROM Books AS b JOIN AuthorBook AS ab USING (BookID) -> JOIN Authors AS a USING (AuthID) -> WHERE AuthLN="Java" -> ) -> ORDER BY BookTitle;
+----------------+-----------+ | BookTitle | Copyright | +----------------+-----------+ | Java | 1934 | | JavaScript | 1992 | | MySQL | 1919 | | Oracle | 1996 | | PERL | 1932 | | PHP | 1966 | | Pl/SQL | 1980 | | www.sqle.ru | 1993 | +----------------+-----------+ 8 rows in set (0.00 sec) mysql> mysql> drop table AuthorBook; Query OK, 0 rows affected (0.02 sec) mysql> drop table Books; Query OK, 0 rows affected (0.06 sec) mysql> drop table Authors; Query OK, 0 rows affected (0.05 sec)</source>
Using the aggregate function in subquery
<source lang="sql">
mysql> mysql> mysql> CREATE TABLE Books(
-> BookID SMALLINT NOT NULL PRIMARY KEY, -> BookTitle VARCHAR(60) NOT NULL, -> Copyright YEAR NOT NULL -> ) -> ENGINE=INNODB;
Query OK, 0 rows affected (0.09 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.sqle.ru", 1993);
Query OK, 8 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, 0 rows affected (0.05 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, 9 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 (AuthID) REFERENCES Authors (AuthID), -> FOREIGN KEY (BookID) REFERENCES Books (BookID) -> ) -> ENGINE=INNODB;
Query OK, 0 rows affected (0.36 sec) mysql> mysql> mysql> INSERT INTO AuthorBook VALUES (1006, 14356),
-> (1008, 15729), -> (1009, 12786), -> (1010, 17695), -> (1011, 15729), -> (1012, 19264), -> (1012, 19354), -> (1014, 16284);
Query OK, 8 rows affected (0.03 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 | +--------+--------+--------+--------+ 9 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.sqle.ru | 1993 | +--------+----------------+-----------+ 8 rows in set (0.02 sec) mysql> select * from AuthorBook; +--------+--------+ | AuthID | BookID | +--------+--------+ | 1009 | 12786 | | 1006 | 14356 | | 1008 | 15729 | | 1011 | 15729 | | 1014 | 16284 | | 1010 | 17695 | | 1012 | 19264 | | 1012 | 19354 | +--------+--------+ 8 rows in set (0.00 sec) mysql> mysql> mysql> SELECT BookTitle, Copyright
-> FROM Books -> WHERE Copyright<(SELECT MAX(Copyright)-50 FROM Books) -> ORDER BY BookTitle;
+-----------+-----------+ | BookTitle | Copyright | +-----------+-----------+ | Java | 1934 | | MySQL | 1919 | | PERL | 1932 | +-----------+-----------+ 3 rows in set (0.00 sec) mysql> mysql> drop table AuthorBook; Query OK, 0 rows affected (0.14 sec) mysql> drop table Books; Query OK, 0 rows affected (0.11 sec) mysql> drop table Authors; Query OK, 0 rows affected (0.03 sec)</source>
