Oracle 存储过程
简要记录存储过程语法与Java程序的调用方式
一 存储过程
首先,我们建立一个简单的表进行存储过程的测试
xuesheng(id integer, xing_ming varchar2(25), yu_wen number, shu_xue number);
insertinto xuesheng values(1,‘zhangsan‘,80,90)
insertinto xuesheng values(2,‘lisi‘,85,87)
1)无返回值的存储过程
begin
insertinto xuesheng values (3, ‘wangwu‘, 90, 90);
commit;
end xs_proc_no;
2)有单个数据值返回的存储过程
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,以上两种与sql server基本类似,而对于返回数据集时,上述方法则不能满足我们的要求。在Oracle中,一般使用ref cursor来返回数据集。示例代码如下:
3)有返回值的存储过程(列表返回)
首先,建立我们自己的包。并定义包中的一个自定义ref cursor
type my_cursor is ref cursor;
end mypackage;
在定义了ref cursor后,可以书写我们的程序代码
p_cursor out mypackage.my_cursor) is
begin
open p_cursor for
select*from xuesheng where shu_xue > shuxue;
end xs_proc_list;
二、程序调用
在本节中,我们使用java语言调用存储过程。其中,关键是使用CallableStatement这个对象,代码如下:
String oracleDriverName = "oracle.jdbc.driver.OracleDriver" ; // 以下使用的Test就是Oracle里的表空间 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" ); //此处为数据库用户名与密码 } 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(); } |
对于列表返回值的存储过程,在上述代码中做简单修改。如下
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);
上述存储过程修改完毕。另外,一个复杂的工程项目中的例子:查询一段数据中间隔不超过十分钟且连续超过100条的数据。即上述代码所调用的getdcsj存储过程
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
;
/
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