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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