MySQL存储过程
(1). 格式
MySQL存储过程创建的格式：CREATE PROCEDURE过程名 ([过程参数[,...]])
[特性 ...]过程体
案例分析：
参数
MySQL存储过程的参数用在存储过程的定义，共有三种参数类型,IN,OUT,INOUT,形式如：
CREATE PROCEDURE([[IN |OUT |INOUT ] 参数名数据类形...])
IN 输入参数:表示该参数的值必须在调用存储过程时指定，在存储过程中修改该参数的值不能被返回，为默认值
OUT 输出参数:该值可在存储过程内部被改变，并可返回
INOUT 输入输出参数:调用时指定，并且可被改变和返回
1）不带参数：
mysql>delimiter //
mysql> create procedure p1()
-> begin
-> declare v_ename varchar(10);
-> declare v_sal int;
-> select ename,sal into v_ename,v_sal from emp where empno=7788; -> select v_ename ;
-> select v_sal;
-> end;
-> //
Query OK, 0 rows affected (0.00 sec)mysql> delimiter ;
mysql> call p1();
+---------+
| v_ename |
+---------+
| SCOTT |
+---------+
1 row in set (0.00 sec)
+-------+
| v_sal |
+-------+
| 3000 |
+-------+
1 row in set (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
2）in参数：
mysql> delimiter //
mysql> create procedure p2(in v_empno int)
-> begin
-> declare v_ename varchar(10);
-> declare v_sal int;
-> select ename,sal into v_ename,v_sal from emp where empno=v_empno; -> select v_ename ;
-> select v_sal;
-> end;
-> //
Query OK, 0 rows affected (0.00 sec)mysql> delimiter ;
执行：
mysql> call p2(7788);
+---------+
| v_ename |
+---------+
| SCOTT |
+---------+
1 row in set (0.00 sec)
+-------+
| v_sal |
+-------+
| 3000 |
+-------+
1 row in set (0.00 sec)
Query OK, 0 rows affected (0.00 sec)
3）out参数:
mysql> delimiter //
mysql> create procedure p3(in v_empno int,out v_sal int)
-> begin
-> declare v_ename varchar(10);
-> select ename,sal into v_ename,v_sal from emp where empno=v_empno; -> select v_ename ;
-> select v_sal;
-> end;
-> //
Query OK, 0 rows affected (0.00 sec)mysql> delimiter ;
执行：
mysql> call p3(7788,@v_sal);
+---------+
| v_ename |
+---------+
| SCOTT |
+---------+
1 row in set (0.00 sec)
+-------+
| v_sal |
+-------+
| 3000 |
+-------+
1 row in set (0.00 sec)
4）存储过程循环
while 循环
mysql> delimiter //
mysql> create procedure p_while()
begin
declare v_empno int;
declare v_count int;
set v_empno=7788;
set v_count=0;
while v_count < 10 do
insert into emp1 select * from emp where empno=v_empno;
set v_count=v_count + 1;
end while;
end;
//
mysql> delimiter ;
repeat 循环：
mysql> delimiter //
mysql> create procedure p_repeat()
begin
declare v_empno int;
declare v_count int;
set v_empno=7788;
set v_count=0;
repeat
insert into emp1 select * from emp where empno=v_empno;
set v_count=v_count + 1;
until v_count > 10
end repeat;
end;
//
mysql> delimiter ;
loop 循环：
mysql> delimiter //
mysql> create procedure p_loop()
begin
declare v_empno int;
declare v_count int;
set v_empno=7788;
set v_count=0;
loop_label:loop
insert into emp1 select * from emp where empno=v_empno;
set v_count=v_count + 1;
if v_count > 10 then
leave loop_label;
end if;
end loop;
end;
//
mysql> delimiter ;
三、Oracle 存储过程
不带参数：
SQL> create or replace procedure proc1 is
3 v_ename emp.ename%type;
4 v_sal emp.sal%type ;
5
6 begin
7 select ename,sal into v_ename,v_sal from emp where empno=&no;
8 dbms_output.put_line('Name is : '||v_ename||' , '||'Salary is : '||v_sal);
9 exception
10 when no_data_found then
11 dbms_output.put_line('you number is not crrect ,please input again !');
12
13 end;
14 /
Procedure created
执行：
SQL> exec proc1;
PL/SQL procedure successfully completed
SQL> set serverout on
SQL> /
Name is : SCOTT , Salary is : 3000
PL/SQL procedure successfully completed
带参数的存储过程：
参数定义中，IN、OUT和IN OUT代表参数的三种不同模式：
IN：当调用存储过程时，该模式的形参接收对应实参的值，并且该是只读的，即不能被修改。默认为IN。
OUT：该形参被认为只能写，既只能为其赋值。在存储过程中不能读它的值。返回时，将该形参值传给相应的实参。
IN OUT：都允许
in 参数：
SQL> create or replace procedure proc2 ( v_empno emp.empno%type) is
-- 如果不指明参数的模式，默认为in
2 v_ename emp.ename%type;
3 v_sal emp.sal%type;
4
5 begin
6 select ename,sal into v_ename,v_sal from emp where empno=v_empno;
7 dbms_output.put_line('Name is : '||v_ename||' , '||'Salary is : '||v_sal);
8 exception
9 when no_data_found then
10 dbms_output.put_line('you number is not crrect ,please input again !');
11
12 end;
13 /
Procedure created
执行：
SQL> exec proc2(7369);
Name is : SMITH , Salary is : 8000
PL/SQL procedure successfully completed
SQL> create or replace procedure proc2 ( v_empno in emp.empno%type) is
2 v_ename emp.ename%type;
3 v_sal emp.sal%type;
4
5 begin
6 select ename,sal into v_ename,v_sal from emp where empno=v_empno;
7 dbms_output.put_line('Name is : '||v_ename||' , '||'Salary is : '||v_sal);
8 exception
9 when no_data_found then
10 dbms_output.put_line('you number is not crrect ,please input again !');
11
12 end;
13 /
out 参数：
SQL> create or replace procedure proc2 ( v_empno in emp.empno%type, v_ename out emp.ename%type,v_sal out emp.sal%type)
2 is
3
4 begin
5 select ename,sal into v_ename,v_sal from emp where empno=v_empno;
6 dbms_output.put_line('Name is : '||v_ename||' , '||'Salary is : '||v_sal);
7 exception
8 when no_data_found then
9 dbms_output.put_line('you number is not crrect ,please input again !');
10
11 end;
12 /
Procedure created
执行：
SQL> var v_ename varchar2(10);
SQL> var v_sal number; //注意：对于number类型不能指明长度
SQL> exec proc2(7788,:v_ename,:v_sal );
Name is : SCOTT , Salary is : 3000
PL/SQL procedure successfully completed
v_ename
---------
SCOTT
v_sal
---------
3000
通过匿名块执行：
SQL> var v_ename varchar2
SQL> var v_sal number
SQL> declare
2 v_empno emp.empno%type := 7788;
3 begin
4 proc2(v_empno ,:v_ename,:v_sal);
5 end;
6 /
Name is : SCOTT , Salary is : 3000
PL/SQL procedure successfully completed
v_ename
---------
SCOTT
v_sal
---------
3000
SQL> declare
2 v_empno emp.empno%type := 7836;
3 v_ename emp.ename%type ;
4 v_sal emp.sal%type;
5 begin
6 proc2(v_empno ,v_ename,v_sal);
7 end;
8 /
in out 参数：
SQL>
create or replace procedure proc3( v_empno in out emp.empno%type)
is
v_ename emp.ename%type;
v_sal emp.sal%type;
begin
select ename,sal into v_ename,v_sal from emp where empno=v_empno;
dbms_output.put_line('Name is : '||v_ename||' , '||'Salary is : '||v_sal);
exception
when no_data_found then
dbms_output.put_line('you number is not crrect ,please input again !');
end;
/
执行：
SQL> var v_empno number;
SQL> exec :v_empno:=7788;
PL/SQL procedure successfully completed
v_empno
---------
7788
SQL> exec proc3(:v_empno);
Employees id is: 7788 , Name is : SCOTT , Salary is : 3000
PL/SQL procedure successfully completed
v_empno
---------
7788
SQL> declare
2 v_empno emp.empno%type;
3 begin
4 v_empno:=7788;
5 proc3(v_empno );
6 end;
7 /
Name is : SCOTT , Salary is : 3000
PL/SQL procedure successfully completed
SQL> create or replace procedure proc3( v_empno in out emp.empno%type)
2
3 is
4
5 v_ename emp.ename%type;
6 v_sal emp.sal%type;
7
8 begin
9 select empno,ename,sal into v_empno, v_ename,v_sal from emp where empno=v_empno;
10 dbms_output.put_line('Employee number is: '||v_empno||' , '||'Name is : '||v_ename||' , '||'Salary is : '||v_sal);
11 exception
12 when no_data_found then
13 dbms_output.put_line('you number is not crrect ,please input again !');
14
15 end;
16 /
Procedure created
执行：
SQL> declare
2 v_empno emp.empno%type;
3 begin
4 v_empno := 7788;
5 proc3(v_empno);
6 end;
7 /
Employee number is: 7788 , Name is : SCOTT , Salary is : 3000
PL/SQL procedure successfully completed
Oracle 存储过程循环：
loop 基本循环：
SQL> declare
2 v_empno emp.empno%type := 7788;
3 v_count number :=0;
4
5 begin
6
7 loop
8 insert into emp1 select * from emp where empno=v_empno;
9 v_count := v_count + 1;
10 exit when v_count >= 10;
11 end loop;
12
13 end;
14 /
PL/SQL procedure successfully completed
for 循环：
SQL> declare
2
3 v_empno emp.empno%type;
4
5 begin
6 v_empno := 7788;
7
8 for i in 1..10 loop
9 insert into emp1 select * from emp where empno=v_empno;
10 end loop;
11
12 end;
13
14
15
16 /
PL/SQL procedure successfully completed
while 循环：
SQL> declare
2 v_empno emp.empno%type;
3 v_count number := 0;
4
5 begin
6 v_empno := 7788;
7
8 while v_count < 10 loop
9 insert into emp1 select * from emp where empno=v_empno;
10 v_count := v_count + 1;
11
12 end loop;
13 end;
14 /
PL/SQL procedure successfully completed