Oracle查詢/存儲過程返回多個結果集

Question

我正在使用oracle數據庫。當我試圖使用單個select查詢獲取數據時，它在數據集中返回了一個表。 如何在oracle中編寫一個選擇查詢或過程，在哪裏可以獲得具有2-3（多個）表的數據集？

Answer 1

這正是我做什麼，這是很簡單的：

 Database db = DatabaseFactory.CreateDatabase("ConnectionString"); 
     object[] results = new object[3]; 
     DbCommand cmd = db.GetStoredProcCommand("DATABASE.SELECT_JOB_HISTORY.GetJobHistoryByEmployeeId",results);    
     DataSet ds = db.ExecuteDataSet(cmd); 
     DataTable dt1 = ds.Tables[0]; 
     DataTable dt2 = ds.Tables[1]; 

Answer 2

據我瞭解你的問題，你想減少你的數據庫的往返旅程。 這可以通過一個存儲過程通過以下方式進行：

http://msdn.microsoft.com/en-us/library/ms971506.aspx#msdnorsps_topic6

Package頭：

CREATE OR REPLACE PACKAGE SELECT_JOB_HISTORY AS 
TYPE T_CURSOR IS REF CURSOR; 
PROCEDURE GetJobHistoryByEmployeeId 
(
    p_employee_id IN NUMBER, 
    cur_JobHistory OUT T_CURSOR 
); 
END SELECT_JOB_HISTORY; 

套餐：

CREATE OR REPLACE PACKAGE BODY SELECT_JOB_HISTORY AS 
PROCEDURE GetJobHistoryByEmployeeId 
(
    p_employee_id IN NUMBER, 
    cur_JobHistory OUT T_CURSOR 
) 
IS 
BEGIN 
    OPEN cur_JobHistory FOR 
    SELECT * FROM JOB_HISTORY 
     WHERE employee_id = p_employee_id; 

END GetJobHistoryByEmployeeId; 
END SELECT_JOB_HISTORY; 

客戶：

// create connection 
OracleConnection conn = new OracleConnection("Data Source=oracledb; 
    User Id=UserID;Password=Password;"); 

// create the command for the stored procedure 
OracleCommand cmd = new OracleCommand(); 
cmd.Connection = conn; 
cmd.CommandText = "SELECT_JOB_HISTORY.GetJobHistoryByEmployeeId"; 
cmd.CommandType = CommandType.StoredProcedure; 

// add the parameters for the stored procedure including the REF CURSOR 
// to retrieve the result set 
cmd.Parameters.Add("p_employee_id", OracleType.Number).Value = 101; 
cmd.Parameters.Add("cur_JobHistory", OracleType.Cursor).Direction = 
    ParameterDirection.Output; 

// open the connection and create the DataReader 
conn.Open(); 
OracleDataReader dr = cmd.ExecuteReader(); 

// output the results and close the connection. 
while(dr.Read()) 
{ 
    for(int i = 0; i < dr.FieldCount; i++) 
     Console.Write(dr[i].ToString() + ";"); 
    Console.WriteLine(); 
} 
conn.Close(); 

如果你必須加入這些表格，你也可以使用正常的連接並在客戶端分割結果（這是許多ORM如何操作的方式）。