• 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

    复制代码
    复制代码
    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;
    复制代码
    复制代码

    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

    复制代码
    复制代码
    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);
    复制代码
    复制代码

    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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  • 原文地址:https://www.cnblogs.com/aaa6818162/p/3951319.html
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