Oracle存儲過程

 

%TYPE屬性 
     在PL/SQL中可以將變量和常量聲明爲內建或用戶定義的數據類型,以引用一個列名,同時繼承他的數據類型和大小。這種動態賦值方法是非常有用的,比如變量引用的列的數據類型和大小改變了,如果使用了%TYPE,那麼用戶就不必修改代碼,否則就必須修改代碼。 

例: 
  v_empno SCOTT.EMP.EMPNO%TYPE; 
  v_salary EMP.SALARY%TYPE; 
   不但列名可以使用%TYPE,而且變量、遊標、記錄,或聲明的常量都可以使用%TYPE。這對於定義相同數據類型的變量非常有用。
 
 
Oracle存儲過程包含三部分:過程聲明,執行過程部分,存儲過程異常。
Oracle存儲過程可以有無參數存儲過程和帶參數存儲過程。
一、無參程序過程語法
 
1 create or replace procedure NoParPro
2 as  ......;
3 begin
4 ......;
5 exception     //存儲過程異常
6     ......;
7 end;
8

        二、帶參存儲過程實例
<!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>--> 1 create or replace procedure queryempname(sfindno emp.empno%type) as
 2        sName emp.ename%type;
 3        sjob emp.job%type;
 4 begin
 5        ....
 7 exception
          ....
14 end;
15

    三、 帶參數存儲過程含賦值方式
<!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>--> 1 create or replace procedure runbyparmeters  (isal in emp.sal%type,
                            sname out varchar,sjob in out varchar)
 2  as icount number;
 3  begin
 4       select count(*) into icount from emp where sal>isal and job=sjob;
 5       if icount=1 then
 6         ....
 9       else
10         ....
12       end if;
13  exception
14       when too_many_rows then
15       DBMS_OUTPUT.PUT_LINE('返回值多於1行');
16       when others then
17       DBMS_OUTPUT.PUT_LINE('在RUNBYPARMETERS過程中出錯!');
18  end;
19

  四、在Oracle中對存儲過程的調用
  過程調用方式一
<!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>--> 1 declare
 2        realsal emp.sal%type;
 3        realname varchar(40);
 4        realjob varchar(40);
 5  begin   //存儲過程調用開始
 6        realsal:=1100;
 7        realname:='';
 8        realjob:='CLERK';
 9        runbyparmeters(realsal,realname,realjob);     --必須按順序
10        DBMS_OUTPUT.PUT_LINE(REALNAME||'   '||REALJOB);
11  END;  //過程調用結束
12

  過程調用方式二
<!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>--> 1 declare
 2       realsal emp.sal%type;
 3       realname varchar(40);
 4       realjob varchar(40);
 5 begin    //過程調用開始
 6       realsal:=1100;
 7       realname:='';
 8       realjob:='CLERK';
 9       runbyparmeters(sname=>realname,isal=>realsal,sjob=>realjob);  --指定值對應變量順序可變
10       DBMS_OUTPUT.PUT_LINE(REALNAME||'   '||REALJOB);
11 END;  //過程調用結束
12
 
 
以下【轉載自】http://www.cnblogs.com/liliu/archive/2011/06/22/2087546.html
   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:
view sourceprint?
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
view sourceprint?
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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