Stupid PHPmyadmin，让我的存储过程一点都不能正确建立，还以为错了

在PHPmyadmin中，我们不能用 "delimiter //" 来指定分隔符，而应当在SQl窗口中手工把 ";" 改为 "//" ，要不我们总是会得到建立存储过程错误的信息——如果你的存储过程用";"来分隔的话。

以下顺便转载一篇不错的Mysql存储过程实例教程：

转载自：http://blog.aladada.com/Joince/2009/02/12/17999

MySQL 存储过程是从 MySQL 5.0 开始增加的新功能。存储过程的优点有一箩筐。不过最主要的还是执行效率和SQL 代码封装。特别是 SQL 代码封装功能，如果没有存储过程，在外部程序访问数据库时（例如 PHP），要组织很多 SQL 语句。特别是业务逻辑复杂的时候，一大堆的 SQL 和条件夹杂在 PHP 代码中，让人不寒而栗。现在有了 MySQL 存储过程，业务逻辑可以封装存储过程中，这样不仅容易维护，而且执行效率也高。

一、MySQL 创建存储过程
“pr_add” 是个简单的 MySQL 存储过程，这个存储过程有两个 int 类型的输入参数 “a”、“b”，返回这两个参数的和。

drop procedure if exists pr_add;

-- 计算两个数之和

create procedure pr_add
(
a int,
b int
)
begin
declare c int;

if a is null then
set a = 0;
end if;

if b is null then
set b = 0;
end if;

set c = a + b;

select c as sum;

/*
return c;- 不能在 MySQL 存储过程中使用。return 只能出现在函数中。
/
end;
二、调用 MySQL 存储过程
call pr_add(10, 20);
执行 MySQL 存储过程，存储过程参数为 MySQL 用户变量。

set @a = 10;
set @b = 20;

call pr_add(@a, @b);
三、MySQL 存储过程特点
创建 MySQL 存储过程的简单语法为：

create procedure 存储过程名字()
(
[in|out|inout] 参数 datatype
)
begin
MySQL 语句;
end;
MySQL 存储过程参数如果不显式指定“in”、“out”、“inout”，则默认为“in”。习惯上，对于是“in” 的参数，我们都不会显式指定。

1. MySQL 存储过程名字后面的“()”是必须的，即使没有一个参数，也需要“()”

2. MySQL 存储过程参数，不能在参数名称前加“@”，如：“@a int”。下面的创建存储过程语法在 MySQL 中是错误的（在 SQL Server 中是正确的）。 MySQL 存储过程中的变量，不需要在变量名字前加“@”，虽然 MySQL 客户端用户变量要加个“@”。

create procedure pr_add
(
@a int,- 错误
b int- 正确
)
3. MySQL 存储过程的参数不能指定默认值。

4. MySQL 存储过程不需要在 procedure body 前面加 “as”。而 SQL Server 存储过程必须加 “as” 关键字。

create procedure pr_add
(
a int,
b int
)
as- 错误，MySQL 不需要 “as”
begin
mysql statement ...;
end;
5. 如果 MySQL 存储过程中包含多条 MySQL 语句，则需要 begin end 关键字。

create procedure pr_add
(
a int,
b int
)
begin
mysql statement 1 ...;
mysql statement 2 ...;
end;
6. MySQL 存储过程中的每条语句的末尾，都要加上分号 “;”

...

declare c int;

if a is null then
set a = 0;
end if;

...
end;
7. MySQL 存储过程中的注释。

/*
这是个
多行 MySQL 注释。
/

declare c int;- 这是单行 MySQL 注释 （注意- 后至少要有一个空格）

if a is null then 这也是个单行 MySQL 注释
set a = 0;
end if;

...
end;
8. 不能在 MySQL 存储过程中使用 “return” 关键字。

set c = a + b;

select c as sum;

/*
return c;- 不能在 MySQL 存储过程中使用。return 只能出现在函数中。
/
end;
9. 调用 MySQL 存储过程时候，需要在过程名字后面加“()”，即使没有一个参数，也需要“()”

call pr_no_param();
10. 因为 MySQL 存储过程参数没有默认值，所以在调用 MySQL 存储过程时候，不能省略参数。可以用 null 来替代。

call pr_add(10, null);

还有这个：http://blog.aladada.com/Joince/2009/02/12/18000

1，前提
需要MySQL 5

2，Hello World
MySQL存储过程之Hello World

DELIMITER$$

DROPPROCEDUREIFEXISTSHelloWorld$$
CREATEPROCEDUREHelloWorld()
BEGIN
SELECT
"HelloWorld!"

;
END$$

DELIMITER;

DELIMITER$

DROP PROCEDURE IF EXISTS HelloWorld$$
CREATE PROCEDURE HelloWorld()
BEGIN
    SELECT "Hello World!";
END$$

DELIMITER ;

3，变量
使用DECLARE 来声明，DEFAULT 赋默认值，SET 赋值

DECLAREcounterINTDEFAULT
0

;
SETcounter=counter+
1

;

DECLARE counter INT DEFAULT 0;
SET counter = counter+1;

4，参数
IN 为默认类型，值必须在调用时指定，值不能返回（值传递）
OUT 值可以返回（指针传递）
INOUT 值必须在调用时指定，值可以返回

CREATEPROCEDUREtest(aINT,OUTbFLOAT,INOUTcINT)

CREATE PROCEDURE test(a INT, OUT b FLOAT, INOUT c INT)

5，条件判断
IF THEN 、ELSEIF 、ELSE 、END IF

DELIMITER$$

DROPPROCEDUREIFEXISTSdiscounted_price$$
CREATEPROCEDUREdiscunted_price(normal_priceNUMERIC(
8

,
2

),OUTdiscount_priceNUMERIC(
8

,
2

))
BEGIN
IF(normal_price>
500

)THEN
SETdiscount_price=normal_price*.
8

;
ELSEIF(normal_price>
100

)THEN
SETdiscount_price=normal_price*.
9

;
ELSE
SETdiscount_price=normal_price;
ENDIF;
END$$

DELIMITER;

DELIMITER$

DROP PROCEDURE IF EXISTS discounted_price$$
CREATE PROCEDURE discunted_price(normal_price NUMERIC(8, 2), OUT discount_price NUMERIC(8, 2))
BEGIN
    IF (normal_price > 500) THEN
        SET discount_price = normal_price .8;
    ELSEIF (normal_price > 100) THEN
        SET discount_price = normal_price .9;
    ELSE
        SET discount_price = normal_price;
    END IF;
END$$

DELIMITER ;

6，循环
LOOP 、END LOOP

DELIMITER$$

DROPPROCEDUREIFEXISTSsimple_loop$$

CREATEPROCEDUREsimple_loop(OUTcounterINT)
BEGIN
SETcounter=
0

;
my_simple_loop:LOOP
SETcounter=counter+
1

;
IFcounter=
10

THEN
LEAVEmy_simple_loop;
ENDIF;
ENDLOOPmy_simple_loop;
END$$

DELIMITER;

DELIMITER$

DROP PROCEDURE IF EXISTS simple_loop$$

CREATE PROCEDURE simple_loop(OUT counter INT)
BEGIN
    SET counter = 0;
    my_simple_loop: LOOP
        SET counter = counter+1;
        IF counter = 10 THEN
            LEAVE my_simple_loop;
        END IF;
    END LOOP my_simple_loop;
END$$

DELIMITER ;

WHILE DO 、END WHILE

DELIMITER$$

DROPPROCEDUREIFEXISTSsimple_while$$

CREATEPROCEDUREsimple_while(OUTcounterINT)
BEGIN
SETcounter=
0

;
WHILEcounter!=
10

DO
SETcounter=counter+
1

;
ENDWHILE;
END$$

DELIMITER;

DELIMITER$

DROP PROCEDURE IF EXISTS simple_while$$

CREATE PROCEDURE simple_while(OUT counter INT)
BEGIN
    SET counter = 0;
    WHILE counter != 10 DO
        SET counter = counter+1;
    END WHILE;
END$$

DELIMITER ;

REPEAT 、UNTILL

DELIMITER$$

DROPPROCEDUREIFEXISTSsimple_repeat$$

CREATEPROCEDUREsimple_repeat(OUTcounterINT)
BEGIN
SETcounter=
0

;
REPEAT
SETcounter=counter+
1

;
UNTILcounter=
10

ENDREPEAT;
END$$

DELIMITER;

DELIMITER$

DROP PROCEDURE IF EXISTS simple_repeat$$

CREATE PROCEDURE simple_repeat(OUT counter INT)
BEGIN
    SET counter = 0;
    REPEAT
        SET counter = counter+1;
    UNTIL counter = 10 END REPEAT;
END$$

DELIMITER ;

7，异常处理
如果用cursor获取SELECT语句返回的所有结果集时应该定义NOT FOUND error handler来防止存储程序提前终结
如果SQL语句可能返回constraint violation等错误时应该创建一个handler来防止程序终结

8，数据库交互
INTO 用于存储单行记录的查询结果

DECLAREtotal_salesNUMERIC(
8

,
2

);
SELECTSUM(sale_value)INTOtotal_salesFROMsalesWHEREcustomer_id=in_customer_id;

DECLARE total_sales NUMERIC(8, 2);
SELECT SUM(sale_value) INTO total_sales FROM sales WHERE customer_id=in_customer_id;

CURSOR 用于处理多行记录的查询结果

DELIMITER$$

DROPPROCEDUREIFEXITScursor_example$$
CREATEPROCEDUREcursor_example()
READSSQLDATA
BEGIN
DECLAREl_employee_idINT;
DECLAREl_salaryNUMERIC(
8

,
2

);
DECLAREl_department_idINT;
DECLAREdoneINTDEFAULT
0

;
DECLAREcur1CURSORFORSELECTemployee_id,salary,department_idFROMemployees;
DECLARECONTINUEHANDLERFORNOTFOUNDSETdone=
1

;

OPENcur1;
emp_loop:LOOP
FETCHcur1INTOl_employee_id,l_salary,l_department_id;
IFdone=
1

THEN
LEAVEemp_loop;
ENDIF;
ENDLOOPemp_loop;
CLOSEcur1;
END$$
DELIMITER;

DELIMITER$

DROP PROCEDURE IF EXITS cursor_example$$
CREATE PROCEDURE cursor_example()
    READS SQL DATA
BEGIN
    DECLARE l_employee_id INT;
    DECLARE l_salary NUMERIC(8,2);
    DECLARE l_department_id INT;
    DECLARE done INT DEFAULT 0;
    DECLARE cur1 CURSOR FOR SELECT employee_id, salary, department_id FROM employees;
    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done=1;

    OPEN cur1;
    emp_loop: LOOP
        FETCH cur1 INTO l_employee_id, l_salary, l_department_id;
        IF done=1 THEN
            LEAVE emp_loop;
        END IF;
    END LOOP emp_loop;
    CLOSE cur1;
END$$
DELIMITER ;

unbounded SELECT语句 用于存储过程返回结果集

DELIMITER$$
DROPPROCEDUREIFEXISTSsp_emps_in_dept$$
CREATEPROCEDUREsp_emps_in_dept(in_employee_idINT)
BEGIN
SELECTemployee_id,surname,firstname,address1,address2,zipcode,date_of_birthFROMemployeesWHEREdepartment_id=in_employee_id;
END$$

DELIMITER;

DELIMITER$
DROP PROCEDURE IF EXISTS sp_emps_in_dept$$
CREATE PROCEDURE sp_emps_in_dept(in_employee_id INT)
BEGIN
    SELECT employee_id, surname, firstname, address1, address2, zipcode, date_of_birth FROM employees WHERE department_id=in_employee_id;
END$$

DELIMITER ;

UPDATE、INSERT、DELETE、CREATE TABLE等非查询语句 也可以嵌入存储过程里

DELIMITER$$

DROPPROCEDUREIFEXITSsp_update_salary$$
CREATEPROCEDUREsp_update_salary(in_employee_idINT,in_new_salaryNUMERIC(
8

,
2

))
BEGIN
IFin_new_salary<
5000

ORin_new_salary>
500000

THEN
SELECT
"Illegalsalary:salarymustbebetween$5000and$500,000"

;
ELSE
UPDATEemployeesSETsalary=in_new_salaryWHEREemployee_id=in_employee_id;
ENDIF:
END$$

DELIMITER;

DELIMITER$

DROP PROCEDURE IF EXITS sp_update_salary$$
CREATE PROCEDURE sp_update_salary(in_employee_id INT, in_new_salary NUMERIC(8,2))
BEGIN
    IF in_new_salary < 5000 OR in_new_salary > 500000 THEN
        SELECT "Illegal salary: salary must be between5000 and500, 000";
    ELSE
        UPDATE employees SET salary=in_new_salary WHERE employee_id=in_employee_id;
    END IF:
END$$

DELIMITER ;

9，使用CALL 调用存储程序

DELIMITER$$

DROPPROCEDUREIFEXISTScall_example$$
CREATEPROCEDUREcall_example(employee_idINT,employee_typeVARCHAR(
20

))
NOSQL
BEGIN
DECLAREl_bonus_amountNUMERIC(
8

,
2

);

IFemployee_type=
'MANAGER'

THEN
CALLcalc_manager_bonus(employee_id,l_bonus_amount);
ELSE
CALLcalc_minion_bonus(employee_id,l_bonus_amount);
ENDIF;
CALLgrant_bonus(employee_id,l_bonus_amount);
END$$
DELIMITER;

DELIMITER$

DROP PROCEDURE IF EXISTS call_example$$
CREATE PROCEDURE call_example(employee_id INT, employee_type VARCHAR(20))
    NO SQL
BEGIN
    DECLARE l_bonus_amount NUMERIC(8,2);

    IF employee_type='MANAGER' THEN
        CALL calc_manager_bonus(employee_id, l_bonus_amount);
    ELSE
        CALL calc_minion_bonus(employee_id, l_bonus_amount);
    END IF;
    CALL grant_bonus(employee_id, l_bonus_amount);
END$$
DELIMITER ;

10，一个复杂的例子

CREATEPROCEDUREputting_it_all_together(in_department_idINT)
MODIFIESSQLDATA
BEGIN
DECLAREl_employee_idINT;
DECLAREl_salaryNUMERIC(
8

,
2

);
DECLAREl_department_idINT;
DECLAREl_new_salaryNUMERIC(
8

,
2

);
DECLAREdoneINTDEFAULT
0

;

DECLAREcur1CURSORFOR
SELECTemployee_id,salary,department_id
FROMemployees
WHEREdepartment_id=in_department_id;

DECLARECONTINUEHANDLERFORNOTFOUNDSETdone=
1

;

CREATETEMPORARYTABLEIFNOTEXISTSemp_raises
(employee_idINT,department_idINT,new_salaryNUMERIC(
8

,
2

));

OPENcur1;
emp_loop:LOOP
FETCHcur1INTOl_employee_id,l_salary,l_department_id;
IFdone=
1

THEN
/*Nomorerows*/
LEAVEemp_loop;
ENDIF;
CALLnew_salary(1_employee_id,l_new_salary);
/*Getnewsalary*/
IF(l_new_salary<>l_salary)THEN
/*Salarychanged*/
UPDATEemployees
SETsalary=l_new_salary
WHEREemployee_id=l_employee_id;
/*Keeptrackofchangedsalaries*/
INSERTINTOemp_raises(employee_id,department_id,new_salary)
VALUES(l_employee_id,l_department_id,l_new_salary);
ENDIF:
ENDLOOPemp_loop;
CLOSEcur1;
/*Printoutthechangedsalaries*/
SELECTemployee_id,department_id,new_salaryfromemp_raises
ORDERBYemployee_id;
END;

CREATE PROCEDURE putting_it_all_together(in_department_id INT)
    MODIFIES SQL DATA
BEGIN
    DECLARE l_employee_id INT;
    DECLARE l_salary NUMERIC(8,2);
    DECLARE l_department_id INT;
    DECLARE l_new_salary NUMERIC(8,2);
    DECLARE done INT DEFAULT 0;

    DECLARE cur1 CURSOR FOR
        SELECT employee_id, salary, department_id
        FROM employees
        WHERE department_id=in_department_id;

    DECLARE CONTINUE HANDLER FOR NOT FOUND SET done=1;

    CREATE TEMPORARY TABLE IF NOT EXISTS emp_raises
        (employee_id INT, department_id INT, new_salary NUMERIC(8,2));

    OPEN cur1;
    emp_loop: LOOP
        FETCH cur1 INTO l_employee_id, l_salary, l_department_id;
        IF done=1 THEN    /* No more rows/
            LEAVE emp_loop;
        END IF;
        CALL new_salary(1_employee_id, l_new_salary); /* Get new salary/
        IF (l_new_salary <> l_salary) THEN  /* Salary changed/
            UPDATE employees
                SET salary=l_new_salary
            WHERE employee_id=l_employee_id;
            /* Keep track of changed salaries/
            INSERT INTO emp_raises(employee_id, department_id, new_salary)
                VALUES (l_employee_id, l_department_id, l_new_salary);
        END IF:
    END LOOP emp_loop;
    CLOSE cur1;
    /* Print out the changed salaries/
    SELECT employee_id, department_id, new_salary from emp_raises
        ORDER BY employee_id;
END;

11，存储方法
存储方法与存储过程的区别
1，存储方法的参数列表只允许IN类型的参数，而且没必要也不允许指定IN关键字
2，存储方法返回一个单一的值，值的类型在存储方法的头部定义
3，存储方法可以在SQL语句内部调用
4，存储方法不能返回结果集
语法：

CREATE
[DEFINER={user|CURRENT_USER}]
PROCEDUREsp_name([proc_parameter[,...]])
[characteristic...]routine_body

CREATE
[DEFINER={user|CURRENT_USER}]
FUNCTIONsp_name([func_parameter[,...]])
RETURNStype
[characteristic...]routine_body

proc_parameter:
[IN|OUT|INOUT]param_nametype

func_parameter:
param_nametype

type:
AnyvalidMySQLdatatype

characteristic:
LANGUAGESQL
|[NOT]DETERMINISTIC
|{CONTAINSSQL|NOSQL|READSSQLDATA|MODIFIESSQLDATA}
|SQLSECURITY{DEFINER|INVOKER}
|COMMENT
'string'

routine_body:
ValidSQLprocedurestatement

CREATE
    [DEFINER = { user | CURRENT_USER }]
    PROCEDURE sp_name ([proc_parameter[,...]])
    [characteristic ...] routine_body

CREATE
    [DEFINER = { user | CURRENT_USER }]
    FUNCTION sp_name ([func_parameter[,...]])
    RETURNS type
    [characteristic ...] routine_body
    
proc_parameter:
    [ IN | OUT | INOUT ] param_name type
    
func_parameter:
    param_name type

type:
    Any valid MySQL data type

characteristic:
    LANGUAGE SQL
  | [NOT] DETERMINISTIC
  | { CONTAINS SQL | NO SQL | READS SQL DATA | MODIFIES SQL DATA }
  | SQL SECURITY { DEFINER | INVOKER }
  | COMMENT 'string'

routine_body:
    Valid SQL procedure statement

各参数说明见CREATE PROCEDURE and CREATE FUNCTION Syntax
例子：

DELIMITER$$

DROPFUNCTIONIFEXISTSf_discount_price$$
CREATEFUNCTIONf_discount_price
(normal_priceNUMERIC(
8

,
2

))
RETURNSNUMERIC(
8

,
2

)
DETERMINISTIC
BEGIN
DECLAREdiscount_priceNUMERIC(
8

,
2

);

IF(normal_price>
500

)THEN
SETdiscount_price=normal_price*.
8

;
ELSEIF(normal_price>
100

)THEN
SETdiscount_price=normal_price*.
9

;
ELSE
SETdiscount_price=normal_price;
ENDIF;

RETURN(discount_price);
END$$

DELIMITER;

DELIMITER$

DROP FUNCTION IF EXISTS f_discount_price$$
CREATE FUNCTION f_discount_price
    (normal_price NUMERIC(8,2))
    RETURNS NUMERIC(8,2)
    DETERMINISTIC
BEGIN
    DECLARE discount_price NUMERIC(8,2);

    IF (normal_price > 500) THEN
        SET discount_price = normal_price .8;
    ELSEIF (normal_price >100) THEN
        SET discount_price = normal_price .9;
    ELSE
        SET discount_price = normal_price;
    END IF;

    RETURN(discount_price);
END$$

DELIMITER ;

12，触发器
触发器在INSERT、UPDATE或DELETE等DML语句修改数据库表时触发
触发器的典型应用场景是重要的业务逻辑、提高性能、监控表的修改等
触发器可以在DML语句执行前或后触发

DELIMITER$$

DROPTRIGGERsales_trigger$$
CREATETRIGGERsales_trigger
BEFOREINSERTONsales
FOREACHROW
BEGIN
IFNEW.sale_value>
500

THEN
SETNEW.free_shipping=
'Y'

;
ELSE
SETNEW.free_shipping=
'N'

;
ENDIF;

IFNEW.sale_value>
1000

THEN
SETNEW.discount=NEW.sale_value*.
15

;
ELSE
SETNEW.discount=
0

;
ENDIF;
END$$

DELIMITER;