Oracle函数将行返回到c#

Question

我想在 oracle 中创建一个 procedure 或 function 以向我的应用程序返回多行不同类型的数据。我在互联网上找到了一些例子，但我无法让它工作......

示例： 我在 oracle 中创建了一个自定义类型：

create type proc_selectall is object 
    (Mjera varchar2(50),
    Status number(10,0),
    Naziv varchar2(50),
    Stat number(10,0));

然后：

create type ret_selectall is table of proc_selectall;

然后创建函数：

create or replace function fsp_SelectAll return ret_selectall
is
l_ret_selectall ret_selectall := ret_selectall();
n integer := 0;
BEGIN 
    for r in(SELECT JEDINICAMJERE.Mjera,
    JEDINICAMJERE.Status, 
    KATEGORIJE.Naziv, 
    KATEGORIJE.Status as Stat
FROM JEDINICAMJERE, KATEGORIJE)
loop
  l_ret_selectall.extend;
  n := n + 1;
  l_ret_selectall(n) := proc_selectall(r.Mjera, r.Status, r.Naziv, r.Stat);
end loop;
return l_ret_selectall;
END;

当我输入这一行时：

select * from table (fsp_SelectAll)

我得到了一个不错的预期输出：

MJERA | STATUS | NAZIV | STAT
tr      0        name1   1
fd      1        name2   1
ds      1        name3   0
.....

后来我尝试在我的应用中获取这些值。 我尝试过这样的事情：

//cmd.Parameters.Add("proc_selectall ", OracleDbType.Object);
//cmd.Parameters.Add("ret_selectall ", OracleDbType.Array);
//cmd.Parameters["ret_selectall "].Direction = ParameterDirection.ReturnValue;
//if (connection.State == ConnectionState.Closed)
//    connection.Open();
//cmd.ExecuteNonQuery();

稍后...

//OracleCommand objCmd = new OracleCommand("select * from table fsp_SelectAll", connection);
//objCmd.CommandType = CommandType.StoredProcedure;
//objCmd.ExecuteNonQuery();
//int size=objCmd.ExecuteReader().FieldCount;

我也试过

//adapter = new OracleDataAdapter(cmd);...

但是关于类型，参数总是有一些错误...... （连接到 oracle 工作。我执行了插入、更新、删除过程，它们工作正常）

我也尝试创建这个程序：（这是我的第一次尝试）

CREATE OR REPLACE PROCEDURE osp_SelectAll (Mjera OUT VARCHAR2,
Status OUT NUMBER, Naziv OUT VARCHAR2,Stat OUT NUMBER) AS 
BEGIN 
    SELECT JEDINICAMJERE.Mjera,
    JEDINICAMJERE.Status, 
    KATEGORIJE.Naziv, 
    KATEGORIJE.Status as Stat INTO Mjera, Status, Naziv, Stat
FROM JEDINICAMJERE, KATEGORIJE;
END osp_SelectAll;

但它没有返回任何一行或多行......我放弃了。

请帮帮我，我需要解决这个问题。

Answer 1

返回一个用户定义的对象并不容易，需要付出很多额外的努力。

试试这个：

create or replace function fsp_SelectAll return SYS_REFCURSOR is
   res SYS_REFCURSOR;
BEGIN 
    OPEN res FOR
    SELECT JEDINICAMJERE.Mjera,
      JEDINICAMJERE.Status, 
      KATEGORIJE.Naziv, 
      KATEGORIJE.Status as Stat
    FROM JEDINICAMJERE, KATEGORIJE;
    return res;
END;

然后

OracleCommand objCmd = new OracleCommand("fsp_SelectAll", connection);
objCmd.CommandType = CommandType.StoredProcedure;
objCmd.Parameters.Add("res", OracleDbType.RefCursor, ParameterDirection.ReturnValue);

var da = new OracleDataAdapter(objCmd);
var dt = new DataTable();
da.Fill(dt);

如果您愿意，也可以使用ExecuteReader()：

OracleDataReader dr = objCmd.ExecuteReader();
while ( dr.Read() ) {
   ...
}
dr.Close();

注意，我从未与.CommandType = CommandType.StoredProcedure; 合作过。如果失败，请使用以下语法：

OracleCommand objCmd = new OracleCommand("BEGIN :res := fsp_SelectAll; END;", connection);
objCmd.CommandType = CommandType.Text;