从存储过程中，返回OUT参数＆amp; OUT光标＆amp;解析结果（Oracle）

Question

问题：是否可以使用OUT返回：

两者：变量＆amp;一个游标，来自我的代码??

---

我在SqlDB上看到了一个类似的问题，但经过一段很长的搜索后发现没有OracleDB的解决方案。

在PLSQL中：

CREATE OR REPLACE
PROCEDURE SPGETRESULTANDSETFLAG
(
 pFilter VARCHAR2,
 pMaxRowCount VARCHAR2,
 pTableID RAW,
 myFlag OUT NUMBER,
 myCursor OUT types.cursorType
)
AS
BEGIN
 Declare
  CountQuery VARCHAR(20000) := '';
  DataQuery VARCHAR(20000) := '';
  ResultingRows NUMBER := -1;
 Begin
  myFlag := -1;

  CountQuery := 'SELECT COUNT(*) FROM ' 
                || F_GET_TABLENAME_FROM_ID(PTABLEID => pTableID)
                || ' WHERE ' || pFilter;
  EXECUTE IMMEDIATE CountQuery INTO ResultingRows;


  --Get the Return Value
  if( pMaxRowCount > ResultingRows ) then myFlag := 1; end if;


  DataQuery := 'SELECT * FROM '
                || F_GET_TABLENAME_FROM_ID(PTABLEID => pTableID) 
                || ' WHERE ' || pFilter; 
  --Get the Return Cursor
  Open myCursor for DataQuery;

 End;
END SPGETRESULTANDSETFLAG;

---

代码背后......

Database db = DBSingleton.GetInstance();
using (DbCommand command = db.GetStoredProcCommand(spName))
{
    //The three Add In Parameters... & then the Add out Parameter as below
    db.AddOutParameter(command, "myFlag", System.Data.DbType.Int32, LocVariable );
    using ( IDataReader reader = db.ExecuteReader(command))
    {
         //Loop through cursor values & store them in code behind class-obj(s)
    }
}

---

我认为这是不可能的，因为我如何阅读价值和＆amp;光标，因为..

如果只有标记param out那么我会使用 db.ExecuteNonQuery（..） ＆安培; 如果只有游标那么我会使用 db.ExecuteReader（..）

Answer 1

是的，可以有多个输出参数。这是一个用于在c＃中调用Oracle存储过程的示例：

OracleParameter op = null;
OracleDataReader dr = null;

/* custom code here. Yours would look a little different */
OracleCommand cmd = (OracleCommand) this.FactoryCache.Connection.CreateCommand();

cmd.CommandText = "pkg_prov_index.getNextPanel";
cmd.CommandType = CommandType.StoredProcedure;

op = new OracleParameter("pCurrentPanelId", OracleType.VarChar);
op.Direction = ParameterDirection.Input;
op.Value = masterProviderIndex.CurrentPanelId;
cmd.Parameters.Add(op);

op = new OracleParameter("pRefCursor", OracleType.Cursor);
op.Direction = ParameterDirection.Output;
cmd.Parameters.Add(op);

op = new OracleParameter("pReturnCode", OracleType.Number);
op.Direction = ParameterDirection.Output;
op.Size = 5;
cmd.Parameters.Add(op);

op = new OracleParameter("pReturnMessage", OracleType.VarChar);
op.Direction = ParameterDirection.Output;
op.Size = 4000;
cmd.Parameters.Add(op);

cmd.ExecuteNonQuery();

returnCode = Convert.ToInt16(cmd.Parameters[2].Value);
returnMessage = cmd.Parameters[3].Value.ToString();

dr = (OracleDataReader) cmd.Parameters[1].Value;

while (dr.Read()) {
}

Answer 2

感谢您的回答

我真的非常渴望得到一个工作成果＆amp;不知何故遇到了一个解决方案＆amp;在阅读了一下后发现了它的工作原理：

---

Oracle存储过程没有变化。

---

代码背后 - 更改如下：

Database db = DBSingleton.GetInstance();
using (DbCommand command = db.GetStoredProcCommand(spName))
{
    //The three Add In Parameters... & then the Add out Parameter as below
    db.AddOutParameter(command, "myFlag", System.Data.DbType.Int32, LocVariable );
    using ( IDataReader reader = db.ExecuteReader(command))
    {
         //Loop through cursor values & store them in code behind class-obj(s)
         //The reader must be closed before trying to get the "OUT parameter"
         reader.Close();

         //Only after reader is closed will any parameter result be assigned
         //So now we can get the parameter value.
         //if reader was not closed then OUT parameter value will remain null
         //Getting the parameter must be done within this code block
         //I could not get it to work outside this code block
         <Type> result = (typecast)command.Parameters["OUT_parameter_name"];
    }
}
//I USED THIS APPROACH TO RETURN MULTIPLE PARAMETERS ALONG WITH THE CURSOR READ

Answer 3

            using (myCmd)
            {
                myCmd.Parameters.AddWithValue("p_session_id", sessionId);
                myCmd.Parameters.AddWithValue("p_user", SessionHelper.UserEmailID);

                OracleParameter retval = new OracleParameter("p_status", OracleType.NVarChar, 35);
                retval.Direction = ParameterDirection.Output;
                myCmd.Parameters.Add(retval);


                OracleParameter retval2 = new OracleParameter("p_status_dtl", OracleType.NVarChar, 300);
                retval2.Direction = ParameterDirection.Output;
                myCmd.Parameters.Add(retval2);

                OracleParameter retval3 = new OracleParameter("p_output", OracleType.Cursor);
                retval3.Direction = ParameterDirection.Output;
                myCmd.Parameters.Add(retval3);
                myCmd.ExecuteNonQuery();
                status = myCmd.Parameters["p_status"].Value.ToString();
                statusDetail = myCmd.Parameters["p_status_dtl"].Value.ToString();

                using (OracleDataReader reader = (OracleDataReader)myCmd.Parameters["p_output"].Value)
                {
                    outPutDt.Load(reader);
                }
            }

}

Answer 4

我不知道您使用哪个库进行Oracle访问...但通常可以将光标声明并将参数声明为参数，并将ExecuteNonQuery与anoynmous PL / SQL块一起使用（其中你调用存储过程）...例如使用Devart dotconnect组件，这是可能的......（不是附属，只是一个快乐的客户）

Answer 5

可以考虑在您的过程中重复查询的替代方法。例如：

CREATE OR REPLACE
PROCEDURE SPGETRESULTANDSETFLAG
(
 pFilter VARCHAR2,
 pTableID RAW,
 myCursor OUT types.cursorType
)
AS
  DataQuery VARCHAR(20000) := '';
BEGIN
  DataQuery := 'SELECT COUNT(*) OVER () AS TheCount, T.* FROM '
                || F_GET_TABLENAME_FROM_ID(PTABLEID => pTableID) 
                || ' AS T WHERE ' || pFilter; 
  --Get the Return Cursor
  Open myCursor for DataQuery;

END SPGETRESULTANDSETFLAG;

通过这种方式，您不必两次查询表，您在结果集的每一行中都有计数。您也可以删除处理max rowcount的参数，并通过获取一行来检查调用例程中的计数值。

只是另一种想法......