Oracle 存儲過程
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：
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
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;
/ |
