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

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）无返回值的存储过程

create or replace procedure xs_proc_no is
begin
insert into xuesheng values (3, 'wangwu', 90, 90);
commit;
end xs_proc_no;

2）有单个数据值返回的存储过程

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

create or replace package mypackage as
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

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

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

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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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