%TYPE屬性
在PL/SQL中可以將變量和常量聲明爲內建或用戶定義的數據類型,以引用一個列名,同時繼承他的數據類型和大小。這種動態賦值方法是非常有用的,比如變量引用的列的數據類型和大小改變了,如果使用了%TYPE,那麼用戶就不必修改代碼,否則就必須修改代碼。
例:
v_empno SCOTT.EMP.EMPNO%TYPE;
v_salary EMP.SALARY%TYPE;
不但列名可以使用%TYPE,而且變量、遊標、記錄,或聲明的常量都可以使用%TYPE。這對於定義相同數據類型的變量非常有用。
Oracle存儲過程包含三部分:過程聲明,執行過程部分,存儲過程異常。
Oracle存儲過程可以有無參數存儲過程和帶參數存儲過程。
一、無參程序過程語法
1 create or replace procedure NoParPro
2 as ......;
3 begin
4 ......;
5 exception //存儲過程異常
6 ......;
7 end;
8
二、帶參存儲過程實例
<!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>--> 1 create or replace procedure queryempname(sfindno emp.empno%type) as
2 sName emp.ename%type;
3 sjob emp.job%type;
4 begin
5 ....
7 exception
....
14 end;
15
三、 帶參數存儲過程含賦值方式
<!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>--> 1 create or replace procedure runbyparmeters (isal in emp.sal%type,
sname out varchar,sjob in out varchar)
2 as icount number;
3 begin
4 select count(*) into icount from emp where sal>isal and job=sjob;
5 if icount=1 then
6 ....
9 else
10 ....
12 end if;
13 exception
14 when too_many_rows then
15 DBMS_OUTPUT.PUT_LINE('返回值多於1行');
16 when others then
17 DBMS_OUTPUT.PUT_LINE('在RUNBYPARMETERS過程中出錯!');
18 end;
19
四、在Oracle中對存儲過程的調用
過程調用方式一
<!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>--> 1 declare
2 realsal emp.sal%type;
3 realname varchar(40);
4 realjob varchar(40);
5 begin //存儲過程調用開始
6 realsal:=1100;
7 realname:='';
8 realjob:='CLERK';
9 runbyparmeters(realsal,realname,realjob); --必須按順序
10 DBMS_OUTPUT.PUT_LINE(REALNAME||' '||REALJOB);
11 END; //過程調用結束
12
過程調用方式二
<!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>--> 1 declare
2 realsal emp.sal%type;
3 realname varchar(40);
4 realjob varchar(40);
5 begin //過程調用開始
6 realsal:=1100;
7 realname:='';
8 realjob:='CLERK';
9 runbyparmeters(sname=>realname,isal=>realsal,sjob=>realjob); --指定值對應變量順序可變
10 DBMS_OUTPUT.PUT_LINE(REALNAME||' '||REALJOB);
11 END; //過程調用結束
12
以下【轉載自】http://www.cnblogs.com/liliu/archive/2011/06/22/2087546.html
簡要記錄存儲過程語法與Java程序的調用方式
一 存儲過程
首先,我們建立一個簡單的表進行存儲過程的測試
create table
xuesheng(id integer, xing_ming varchar2(25), yu_wen number, shu_xue number);
insert into xuesheng values(1,'zhangsan',80,90)
insert into xuesheng values(2,'lisi',85,87)
1)無返回值的存儲過程
create or replace procedure xs_proc_no is
begin
insert into xuesheng values (3, 'wangwu', 90, 90);
commit;
end xs_proc_no;
2)有單個數據值返回的存儲過程
create or replace procedure xs_proc(temp_name in varchar2,
temp_num out number) is
num_1 number;
num_2 number;
begin
select yu_wen, shu_xue
into num_1, num_2
from xuesheng
where xing_ming = temp_name;
--dbms_output.put_line(num_1 + num_2);
temp_num := num_1 + num_2;
end;
其中,以上兩種與sql server基本類似,而對於返回數據集時,上述方法則不能滿足我們的要求。在Oracle中,一般使用ref cursor來返回數據集。示例代碼如下:
3)有返回值的存儲過程(列表返回)
首先,建立我們自己的包。並定義包中的一個自定義ref cursor
create or replace package mypackage as
type my_cursor is ref cursor;
end mypackage;
在定義了ref cursor後,可以書寫我們的程序代碼
create or replace procedure xs_proc_list(shuxue in number,
p_cursor out mypackage.my_cursor) is
begin
open p_cursor for
select * from xuesheng where shu_xue > shuxue;
end xs_proc_list;
二、程序調用
在本節中,我們使用java語言調用存儲過程。其中,關鍵是使用CallableStatement這個對象,代碼如下:
view sourceprint?
String oracleDriverName = "oracle.jdbc.driver.OracleDriver";
// 以下使用的Test就是Oracle裏的表空間
String oracleUrlToConnect = "jdbc:oracle:thin:@127.0.0.1:1521:orcl";
Connection myConnection = null;
try {
Class.forName(oracleDriverName);
} catch (ClassNotFoundException ex) {
ex.printStackTrace();
}
try {
myConnection = DriverManager.getConnection(oracleUrlToConnect,
"xxxx", "xxxx");//此處爲數據庫用戶名與密碼
} catch (Exception ex) {
ex.printStackTrace();
}
try {
CallableStatement proc=null;
proc=myConnection.prepareCall("{call xs_proc(?,?)}");
proc.setString(1, "zhangsan");
proc.registerOutParameter(2, Types.NUMERIC);
proc.execute();
String teststring=proc.getString(2);
System.out.println(teststring);
} catch (Exception ex) {
ex.printStackTrace();
}
對於列表返回值的存儲過程,在上述代碼中做簡單修改。如下
CallableStatement proc=null;
proc=myConnection.prepareCall("{call getdcsj(?,?,?,?,?)}");
proc.setString(1, strDate);
proc.setString(2, jzbh);
proc.registerOutParameter(3, Types.NUMERIC);
proc.registerOutParameter(4, OracleTypes.CURSOR);
proc.registerOutParameter(5, OracleTypes.CURSOR);
proc.execute();
ResultSet rs=null;
int total_number=proc.getInt(3);
rs=(ResultSet)proc.getObject(4);
上述存儲過程修改完畢。另外,一個複雜的工程項目中的例子:查詢一段數據中間隔不超過十分鐘且連續超過100條的數據。即上述代碼所調用的getdcsj存儲過程
view sourceprint?
create or replace procedure getDcsj(var_flag in varchar2,
var_jzbh in varchar2,
number_total out number,
var_cursor_a out mypackage.my_cursor,
var_cursor_b out mypackage.my_cursor) is
total number;
cursor cur is
select sj, flag
from d_dcsj
where jzbh = var_jzbh
order by sj desc
for update;
last_time date;
begin
for cur1 in cur loop
if last_time is null or cur1.sj >= last_time - 10 / 60 / 24 then
update d_dcsj set flag = var_flag where current of cur;
last_time := cur1.sj;
else
select count(*) into total from d_dcsj where flag = var_flag;
dbms_output.put_line(total);
if total < 100 then
update d_dcsj set flag = null where flag = var_flag;
last_time := null;
update d_dcsj set flag = var_flag where current of cur;
else
open var_cursor_a for
select *
from d_dcsj
where flag = var_flag
and jzbh = var_jzbh
and zh = 'A'
order by sj desc;
number_total := total;
open var_cursor_b for
select *
from d_dcsj
where flag = var_flag
and jzbh = var_jzbh
and zh = 'B'
order by sj desc;
number_total := total;
exit;
end if;
end if;
end loop;
select count(*) into total from d_dcsj where flag = var_flag;
dbms_output.put_line(total);
if total < 100 then
open var_cursor_a for
select * from d_dcsj where zh = 'C';
open var_cursor_b for
select * from d_dcsj where zh = 'C';
else
open var_cursor_a for
select *
from d_dcsj
where flag = var_flag
and jzbh = var_jzbh
and zh = 'A'
order by sj desc;
number_total := total;
open var_cursor_b for
select *
from d_dcsj
where flag = var_flag
and jzbh = var_jzbh
and zh = 'B'
order by sj desc;
number_total := total;
end if;
commit;
end;
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