Oracle :一次数据库连接，返回多个结果集

1. 一次数据库连接，返回多个结果集

1.1 建立包规范

create or replace package QX_GDJTJ is
  -- Author  : xxx
  -- Created : 2012-1-1
  -- Purpose : 统计主设备缺陷

TYPE T_CURSOR IS REF CURSOR;
PROCEDURE GETGDJQXTJ
(
    cur_id in varchar,
    cur_GDJQXTJ1 OUT T_CURSOR,
    cur_GDJQXTJ2 OUT T_CURSOR,
    cur_GDJQXTJ3 OUT T_CURSOR
);

end QX_GDJTJ;

1.2 建立包体

create or replace package body QX_GDJTJ is
PROCEDURE GETGDJQXTJ
(
    cur_id in varchar,
    cur_GDJQXTJ1 OUT T_CURSOR,
    cur_GDJQXTJ2 OUT T_CURSOR,
    cur_GDJQXTJ3 OUT T_CURSOR
)
IS
BEGIN
OPEN cur_GDJQXTJ1 FOR
select (select count(0) from HVM_VIEW_QX where voltage='500kV' and gdjid=cur_id )-(select count(0) from HVM_VIEW_QX where voltage='500kV' and gdjid=cur_id and cljg like '%合格%' and cljg not like '%不合格%') from dual;
OPEN cur_GDJQXTJ2 FOR
select (select count(0) from HVM_VIEW_QX where voltage='220kV' and gdjid=cur_id )-(select count(0) from HVM_VIEW_QX where voltage='220kV' and gdjid=cur_id and cljg like '%合格%' and cljg not like '%不合格%') from dual;
OPEN cur_GDJQXTJ3 FOR
select (select count(0) from HVM_VIEW_QX where voltage='110kV' and gdjid=cur_id )-(select count(0) from HVM_VIEW_QX where voltage='110kV' and gdjid=cur_id and cljg like '%合格%' and cljg not like '%不合格%') from dual;
end GETGDJQXTJ;
end QX_GDJTJ;

1.3 C#调用，返回结果集

public static DataSet GetDataSet(string gdjId, string proName, string[] cursors)
{
    OracleConnection Conn = GetConn();
    DataSet ds = new DataSet();
    try
    {
　　　　OracleCommand cmd = new OracleCommand();
　　　　cmd.Connection = Conn;
　　　　cmd.CommandText = proName;
　　　　cmd.CommandType = CommandType.StoredProcedure;
　　　　cmd.Parameters.Add("cur_id", OracleType.VarChar).Value = gdjId;
　　　　for (int i = 0; i < cursors.Length; i++)
　　　　{
　　　　　　cmd.Parameters.Add(cursors[i], OracleType.Cursor).Direction = ParameterDirection.Output;
　　　　}
        OracleDataAdapter da = new OracleDataAdapter(cmd);
        da.Fill(ds);
    }
    catch (System.Data.OracleClient.OracleException ex)
    {
        throw new Exception(ex.Message);
    }
    finally
    {
        Conn.Close();
    }
    return ds;
}

2. 基础知识

在给出具体的方法之前，我们先来看看以下几个名词的含义。

2.1 包的组成

包头(package)：包头部分申明包内数据类型，常量，变量，游标，子程序和异常错误处理，这些元素为包的公有元素。

包主体(package body)：包主体则是包定义部分的具体实现，它负责为包头中所声明子程序提供具体的实现，在包主体中还可以声明包的私有元素。

包头和包主体分开编译，并作为两个分开的对象分别存放在数据库字典中。

2.2 包的语法规则

包头的语法如下：

create or replace package 包名
As | IS
          procedure 过程名();
          Function 函数名() return 数据类型;
           变量定义;
          异常定义;
          光标定义;
          ...........
          ...........
End 包名; 

包体创建的语法：

create or replace Package Body 包名
As | IS
            Procedure 过程定义;
            Procedure 过程定义;
             Function 函数定义;
            Function 函数定义;
                .........;  

end 包名; 

2.3 示例

示例1

create or replace package circle_package
as
pi number(6,2):=3.14;
function fun_get_circle_area(param_r number) return number;
function fun_get_circle_c(param_r number) return number;
end circle_package;
 /

create or replace package  body circle_package
as
function fun_get_circle_area(param_r number) return number
as
begin
return pi*power(param_r,2);
end;

function fun_get_circle_c(param_r number) return number
as
begin
return pi*param_r*2;
end;
end circle_package;
 /

declare
v_area number(6,2);
v_c number(6,2);
v_r number(5):=3;
begin
v_area:=circle_package.fun_get_circle_area(v_r);
v_c:=circle_package.fun_get_circle_c(v_r);
Dbms_output.put_line('圆的半径：'||v_r );
Dbms_output.put_line('圆的周长：'||v_c );
Dbms_output.put_line('圆的面积：'||v_area  );
end;

SQL> set serveroutput on;
SQL> /

圆的半径：3
圆的周长：18.84
圆的面积：28.26

PL/SQL procedure successfully completed

示例2

下面是student 和SC表的定义：

    CREATE TABLE Student
           (Sno CHAR(9) PRIMARY KEY,
            Sname CHAR(20) NOT NULL,
            Ssex CHAR(4),
            Sage SMALLINT,
            Sdept CHAR(20)) tablespace starivespace;  

    CREATE TABLE SC
             (Sno CHAR(9) NOT NULL,
              Cno CHAR(6) NOT NULL,
              Grade SMALLINT,
              PRIMARY KEY (Sno,Cno),
              constraint f1 FOREIGN KEY (Sno) REFERENCES Student(Sno),
              FOREIGN KEY (Cno) REFERENCES Course(Cno)
          ) tablespace starivespace  

实例：定义一个包，实现如果功能： 输入学号，分别返回该学生的所在系和相应的选课成绩（如果有多门成绩，那么就输出多门成绩）。

定义包头：

    create or replace
      package sdept_or_grade as
       procedure print_sdept(psno char);
       procedure print_grade(psno char);
       end;
       /  

1. 程序包已创建。

创建包体：

    create or replace
    package body sdept_or_grade
    as
    procedure print_sdept(psno char) as
        psdept student.sdept%type;
    begin
         select sdept into psdept
        from student
        where sno=psno;
        dbms_output.put_line(psdept);
        exception
        when no_data_found then
            dbms_output.put_line(\'Invalid student number\');
    end;
    procedure print_grade(psno char) as
        pgrade SC.grade%type;
    cursor printgrade is select grade into pgrade
        from sc
        where sno=psno;  

    begin
        open printgrade;
       loop
        fetch printgrade into pgrade;
            dbms_output.put_line(pgrade);
    exit when printgrade%notfound;
    end loop;
    close printgrade;
    exception
        when no_data_found then
            dbms_output.put_line(\'Invalid student number\');
    end;
    end;
    /  

程序包体已创建。

获取结果：

SQL> set serveroutput on;
SQL>
SQL> execute sdept_or_grade.print_sdept(\'0201\');
cs  

PL/SQL 过程已成功完成。  

SQL>
SQL> execute sdept_or_grade.print_grade(\'0201\');
89
64
50
50  

PL/SQL 过程已成功完成。

参考文章

gooliugle，Oracle :一次数据库连接，返回多个结果集(带参数)！。

德州仪器， Oracle package包头和package body包体例子