SQL/MySQL/Procedure Function/Function — различия между версиями

Текущая версия на 10:17, 26 мая 2010

Содержание

1 A function that takes a parameter, performs an operation using an SQL function, and returns the result
2 Create a procedure for "READS SQL DATA"
3 Creating Functions
4 Nested function call
5 Single statement function
6 To remove a stored function, use the DROP command
7 Using buildin function in user-defined function

A function that takes a parameter, performs an operation using an SQL function, and returns the result

 
mysql>
mysql>
mysql> CREATE FUNCTION hello (s CHAR(20)) RETURNS CHAR(50)
    ->     RETURN CONCAT("Hello, ",s,"!");
Query OK, 0 rows affected (0.00 sec)
mysql>
mysql>
mysql> SELECT hello("world");
+----------------+
| hello("world") |
+----------------+
| Hello, world!  |
+----------------+
1 row in set (0.00 sec)
mysql>
mysql>
mysql> drop function hello;
Query OK, 0 rows affected (0.00 sec)
mysql>
mysql>

Create a procedure for "READS SQL DATA"

 
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 (0.02 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 (0.01 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> delimiter $$
mysql>
mysql> CREATE PROCEDURE myProc(in_id int)
    ->        READS SQL DATA
    -> BEGIN
    ->     SELECT first_name,last_name
    ->       FROM employee
    ->      WHERE id=in_id;
    -> END$$
Query OK, 0 rows affected (0.00 sec)
mysql>
mysql> delimiter ;
mysql> call myProc(1);
+------------+-----------+
| first_name | last_name |
+------------+-----------+
| Jason      | Martin    |
+------------+-----------+
1 row in set (0.00 sec)
Query OK, 0 rows affected (0.02 sec)
mysql> drop procedure myProc;
Query OK, 0 rows affected (0.00 sec)
mysql>
mysql>
mysql> drop table Employee;
Query OK, 0 rows affected (0.00 sec)
mysql>

Creating Functions

 
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 (0.00 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>
mysql> CREATE FUNCTION myProc (cost DECIMAL(10,2), sal DECIMAL(10,2))
    -> RETURNS DECIMAL(10,2)
    -> RETURN cost * 1.05 + sal;
Query OK, 0 rows affected (0.00 sec)
mysql>
mysql>
mysql>
mysql> SELECT id, first_name, myProc(salary, salary) AS total
    -> FROM employee;
+------+------------+----------+
| id   | first_name | total    |
+------+------------+----------+
|    1 | Jason      |  2530.85 |
|    2 | Alison     | 13656.65 |
|    3 | James      | 13416.80 |
|    4 | Celia      |  4806.80 |
|    5 | Robert     |  4786.30 |
|    6 | Linda      |  8861.70 |
|    7 | David      | 16190.45 |
|    8 | James      |  2527.20 |
+------+------------+----------+
8 rows in set, 24 warnings (0.00 sec)
mysql>
mysql>
mysql>
mysql> drop function myProc;
Query OK, 0 rows affected (0.00 sec)
mysql>
mysql> drop table Employee;
Query OK, 0 rows affected (0.02 sec)

Nested function call

 
mysql>
mysql> DELIMITER //
mysql>
mysql> CREATE FUNCTION myFunction (rush_ship INT(10)) RETURNS DECIMAL(10,2)
    -> BEGIN
    ->
    -> DECLARE rush_shipping_cost DECIMAL(10,2);
    ->
    -> CASE rush_ship
    -> WHEN 1 THEN
    ->         SET rush_shipping_cost = 20.00;
    -> WHEN 2 THEN
    ->         SET rush_shipping_cost = 15.00;
    -> WHEN 3 THEN
    ->         SET rush_shipping_cost = 10.00;
    -> ELSE
    ->         SET rush_shipping_cost = 0.00;
    -> END CASE;
    ->
    -> RETURN rush_shipping_cost;
    ->
    -> END
    -> //
Query OK, 0 rows affected (0.00 sec)
mysql>
mysql> CREATE FUNCTION myFunction1 (item_sum DECIMAL(10,2))
    -> RETURNS DECIMAL(10,1)
    -> BEGIN
    ->
    -> RETURN myFunction(1);
    ->
    -> END
    -> //
Query OK, 0 rows affected (0.00 sec)
mysql>
mysql> DELIMITER ;
mysql>
mysql>
mysql> select myFunction1(1);
+----------------+
| myFunction1(1) |
+----------------+
|           20.0 |
+----------------+
1 row in set (0.00 sec)
mysql>
mysql>
mysql> drop function myFunction1;
Query OK, 0 rows affected (0.00 sec)
mysql> drop function myFunction;
Query OK, 0 rows affected (0.00 sec)
mysql>

Single statement function

 
mysql>
mysql> DELIMITER //
mysql> CREATE FUNCTION calc_tax (cost DECIMAL(10,2)) RETURNS DECIMAL(10,2)
    -> RETURN cost * .05
    -> //
Query OK, 0 rows affected (0.00 sec)
mysql>
mysql> DELIMITER ;
mysql>
mysql> select calc_tax(123.123);
+-------------------+
| calc_tax(123.123) |
+-------------------+
|              6.16 |
+-------------------+
1 row in set, 2 warnings (0.00 sec)
mysql>
mysql> drop function calc_tax;
Query OK, 0 rows affected (0.00 sec)

To remove a stored function, use the DROP command

 
mysql>
mysql> DELIMITER //
mysql>
mysql> CREATE FUNCTION myFunction (item_sum DECIMAL(10,2))
    -> RETURNS DECIMAL(10,1)
    -> BEGIN
    ->
    ->
    -> RETURN ROUND(item_sum,1);
    ->
    -> END
    -> //
Query OK, 0 rows affected (0.00 sec)
mysql> DELIMITER ;
mysql>
mysql> select myFunction(123.12);
+--------------------+
| myFunction(123.12) |
+--------------------+
|              123.1 |
+--------------------+
1 row in set (0.00 sec)
mysql>
mysql>
mysql> DROP FUNCTION test.myFunction;
Query OK, 0 rows affected (0.00 sec)
mysql>
mysql>
mysql>

Using buildin function in user-defined function

 
mysql>
mysql> DELIMITER //
mysql>
mysql> CREATE FUNCTION myFunction (item_sum DECIMAL(10,2))
    -> RETURNS DECIMAL(10,1)
    -> BEGIN
    ->
    ->
    -> RETURN ROUND(item_sum,1);
    ->
    -> END
    -> //
Query OK, 0 rows affected (0.00 sec)
mysql> DELIMITER ;
mysql>
mysql> select myFunction(123.12);
+--------------------+
| myFunction(123.12) |
+--------------------+
|              123.1 |
+--------------------+
1 row in set (0.02 sec)
mysql>
mysql> drop function myFunction;
Query OK, 0 rows affected (0.00 sec)

SQL/MySQL/Procedure Function/Function — различия между версиями

Текущая версия на 10:17, 26 мая 2010

Содержание

A function that takes a parameter, performs an operation using an SQL function, and returns the result

Create a procedure for "READS SQL DATA"

Creating Functions

Nested function call

Single statement function

To remove a stored function, use the DROP command

Using buildin function in user-defined function

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Версия 13:46, 26 мая 2010 (просмотреть исходный код) (обсуждение) ← Предыдущая правка	Текущая версия на 10:17, 26 мая 2010 (просмотреть исходный код) Admin (обсуждение \| вклад) м (1 версия)
(нет различий)