MySql存储过程与函数详解

CREATE TABLE 
 t_user 
 ( 
 USER_ID INT NOT NULL AUTO_INCREMENT, 
 USER_NAME CHAR(30) NOT NULL, 
 USER_PASSWORD CHAR(10) NOT NULL, 
 USER_EMAIL CHAR(30) NOT NULL, 
 PRIMARY KEY (USER_ID), 
 INDEX IDX_NAME (USER_NAME) 
 ) 
 ENGINE=InnoDB DEFAULT CHARSET=utf8; 

//创建储存过程.cmd 中运行 
CREATE PROCEDURE SP_SEARCH(IN p_name CHAR(20)) 
BEGIN 
IF p_name is null or p_name='' THEN 
SELECT * FROM t_user; 
ELSE 
SELECT * FROM t_user WHERE USER_NAME LIKE p_name; 
END IF; 
END 

//调用并输出结果 
CALL SP_SEARCH('林炳文') 

//带OUT返回的 
CREATE PROCEDURE SP_SEARCH2(IN p_name CHAR(20),OUT p_int INT) 
BEGIN 
IF p_name is null or p_name='' THEN 
SELECT * FROM t_user; 
ELSE 
SELECT * FROM t_user WHERE USER_NAME LIKE p_name; 
END IF; 
SELECT FOUND_ROWS() INTO p_int; 
END 

//调用并输出结果 
CALL SP_SEARCH2('林%',@p_num); 
SELECT @p_num; 

//带INOUT的存储过程 
CREATE PROCEDURE sp_inout(INOUT p_num INT) 
BEGIN 
SET p_num=p_num*10; 
END 
//调用并输出结果 
SET @p_num=2; 
call sp_inout(@p_num); 
SELECT @p_num; 

DECLARE var_name[,…] type [DEFAULT value] 
Var_name:指定局部变量的名称 
Type:用于声明局部变量的数据类型 
default子句:用于为局部变量指定一个默认值。若没有指定，默认为null. 

Declare cid int(10); 

Select col_name[,…] into var_name[,…] table_expr 
Col_name:用于指定列名 
Var_name:用于指定要赋值的变量名 
Table_expr:表示select语句中的from字句及后面的语法部分 

DECLARE handler_type HANDLER FOR condition_value[,…] sp_statement 
handler_type:CONTINUE | EXIT | UNDO 
Condition_value:Sqlwarning | not found | sqlexception 

If search_condition then statement_list 
[elseif search_condition then statement_list]… 
[else statement_list] 
End if 

CREATE TABLE 
 t_student 
 ( 
 STU_ID INT NOT NULL, 
 STU_NAME CHAR(10) NOT NULL, 
 STU_CLASS INT NOT NULL, 
 STU_SEX CHAR(2) NOT NULL, 
 STU_AGE INT NOT NULL, 
 PRIMARY KEY (STU_ID) 
 ) 
 ENGINE=InnoDB DEFAULT CHARSET=utf8; 

CREATE TABLE 
 t_grade 
 ( 
 STU_ID INT NOT NULL, 
 STU_SCORE INT NOT NULL, 
 FOREIGN KEY (STU_ID) REFERENCES t_student (STU_ID), 
 INDEX STU_ID (STU_ID) 
 ) 
 ENGINE=InnoDB DEFAULT CHARSET=utf8; 

//带多重IF的存储过程 
CREATE PROCEDURE SP_SCHOLARSHIP_LEVEL(IN p_level char(1)) 
BEGIN 
IF p_level ='A' THEN 
SELECT * FROM t_grade WHERE STU_SCORE >=90; 
ELSEIF p_level ='B' THEN 
SELECT * FROM t_grade WHERE STU_SCORE <90 AND STU_SCORE>=80; 
ELSEIF p_level ='C' THEN 
SELECT * FROM t_grade WHERE STU_SCORE <80 AND STU_SCORE>=70; 
ELSEIF p_level ='D' THEN 
SELECT * FROM t_grade WHERE STU_SCORE <60; 
ELSE 
SELECT * FROM t_grade; 
END IF; 
END 

//调用并输出结果 
CALL SP_SCHOLARSHIP_LEVEL('A'); 

Case case_value 
When when_value then statement_list 
[When when_value then statement_list]… 
[else statement_list] 
End case

Case 
When search_condition then statement_list 
End case 

CREATE PROCEDURE SP_SCHOLARSHIP_LEVEL3(IN p_level char(1)) 
BEGIN 
DECLARE p_num int DEFAULT 0; 
CASE p_level 
WHEN 'A' THEN 
SET p_num=90; 
WHEN 'B' THEN 
SET p_num=80; 
WHEN 'C' THEN 
SET p_num=70; 
WHEN 'D' THEN 
SET p_num=60; 
ELSE 
SET p_num=0; 
END CASE; 
SELECT * FROM t_grade g, t_student s WHERE g.STU_ID=s.STU_ID AND g.STU_SCORE >= p_num ; 
END 

//调用并输出结果 
CALL SP_SCHOLARSHIP_LEVEL3('d'); 

[begin_label:] 
while search_condition do 
Statement_list 
End while 
[end_label] 

//带while的存储过程 
CREATE PROCEDURE sp_cal(IN p_num INT,OUT p_result INT) 
BEGIN 
 SET p_result=1; 
 WHILE p_num > 1 DO 
 SET p_result = p_num * p_result; 
 SET p_num = p_num-1; 
 END WHILE; 
END 
//调用并输出结果 
CALL sp_cal(5,@result); 
SELECT @result; 

[begin_label:] 
repeat 
Statement_list 
Until search_condition 
End repeat 
[end_label] 

//带repeat的存储过程 
CREATE PROCEDURE sp_cal2(IN p_num INT,OUT p_result INT) 
BEGIN 
 SET p_result=1; 
 REPEAT 
 SET p_result = p_num * p_result; 
 SET p_num = p_num-1; 
 UNTIL p_num<=1 
 END REPEAT; 
END 
//调用并输出结果 
CALL sp_cal2(5,@result); 
SELECT @result; 

Call sp_name([parameter[,…]]); 
Sp_name被调用存储过程的名称 
Parameter:指定调用存储过程所要使用的参数。

MySQL中，创建存储函数的基本形式如下：
CREATE FUNCTION sp_name([func_parameter[,...]]) 
RETURNS type 
[characteristic ...] routine_body 
Return 

Select sp_name([func_parameter…]) 
Select fn_search(2); 

/**函数使用**/ 
CREATE FUNCTION sp_cal_max(p_num1 INT,p_num2 INT) 
RETURNS INT 
BEGIN 
IF p_num1 >= p_num2 THEN 
RETURN p_num1; 
ELSE 
RETURN p_num2; 
END IF; 
END 

SET @p_num1=2; 
SET @p_num2=34; 
SELECT sp_cal_max(@p_num1,@p_num2); 

Declare cursor_name cursor forselect_statement; 
Cursor_name:光标名称 
Select_statement:select语句的内容 
Declare cur_employee cursor forselect name,age from employee; 

Open cursor_name 
Open cur_employee; 

Fetch cur_name intovar_name[,var_name…]; 
Cur_name表示光标的名称 
Var_name表示将光标中的select语句查询出来的信息存入该参数。Var_name必须在声明光标前就定义好。 
Fetch cur_employee intoemp_name,emp_age; 

Close cursor_name; 
Close cur_employee; 

CREATE TABLE `test_cur1` ( 
 `id` int(11) NOT NULL auto_increment, 
 `type` char(11) default NULL, 
 `order1` char(11) default NULL, 
 PRIMARY KEY (`id`) 
) 
INSERT INTO `test_cur1` VALUES (1, '145', 'd1'); 
INSERT INTO `test_cur1` VALUES (2, '134', '1d'); 
INSERT INTO `test_cur1` VALUES (3, '123', '1ad'); 
INSERT INTO `test_cur1` VALUES (4, '121', '1as'); 
 
CREATE TABLE `test_cur2` ( 
 `id` int(11) NOT NULL auto_increment, 
 `type` char(11) default NULL, 
 `order1` char(11) default NULL, 
 PRIMARY KEY (`id`) 
) 

create procedure get_cur () 
BEGIN 
 DECLARE done INT DEFAULT 0; 
 DECLARE ID int(11); 
 DECLARE type char(11); 
 DECLARE order1 char(11); 
 DECLARE mycur CURSOR FOR SELECT * FROM test_cur1;//定义光标 
 DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET done = 1; 
 //打开光标 
 OPEN mycur; 
 //开始循环 
 REPEAT 
 FETCH mycur INTO ID,type,order1;//取出光标的内容到临时变量 
 IF NOT done THEN 
 INSERT INTO test_cur2 VALUES (ID,type,order1);//插入到另一张表 
 END IF; 
 UNTIL done END REPEAT;//当done=1时结束循环 
 //关闭光标 
 CLOSE mycur; 
END 

call get_cur()