C# 調用存儲過程操作 OUTPUT參數和Return返回值

本文轉載：http://www.cnblogs.com/libingql/archive/2010/05/02/1726104.html

存儲過程是存放在數據庫服務器上的預先編譯好的sql語句。使用存儲過程，可以直接在數據庫中存儲並運行功能強大的任務。存儲過程在第一應用程序執行時進行語法檢查和編譯，編譯好的版本保存在高速緩存中。在執行重復任務時，存儲過程可以提高性能和一致性。由於存儲過程可以將一系列對數據庫的操作放在數據庫服務器上執行，因而可以降低Web服務器的負載，提高整個系統的性能。

 

1、創建存儲過程

CREATE PROC [DBO].[GetOrdersByOrderDate]
    @OrderDate DATETIME
AS
    SELECT
        [OrderID],[CustomerID],[OrderDate]
    FROM
        [Orders]
    WHERE
        [OrderDate] >= @OrderDate
 
 
USE Northwind
GO
EXEC GetOrdersByOrderDate'1996-10-10 0:00:00'

2、調用存儲過程

SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["Northwind"].ConnectionString);
 
            try
            {
                SqlCommand cmd = new SqlCommand();
                cmd.CommandText = "[GetOrdersByOrderDate]";
                cmd.Connection = conn;
 
                cmd.CommandType = CommandType.StoredProcedure;
 
                cmd.Parameters.Add("@OrderDate", SqlDbType.DateTime, 8).Value = "1998-5-5";
 
                conn.Open();
 
                SqlDataAdapter da = new SqlDataAdapter();
                da.SelectCommand = cmd;
 
                DataSet ds = new DataSet();
 
                da.Fill(ds);
 
                gvOrders.DataSource = ds;
                gvOrders.DataBind();
            }
            catch (SqlException ex)
            {
                throw new Exception(ex.Message, ex);
            }
            finally
            {
                conn.Close();
            }
        }

3、輸出參數

存儲過程可以通過輸出參數來返回值。

CREATE PROC [DBO].[GetOrderDetailsTotalByProductID]
    @ProductID INT,
    @Total MONEY OUTPUT
AS
    SELECT @Total = SUM([UnitPrice]*[Quantity])
    FROM
        [Order Details]
    WHERE
        [ProductID] = @ProductID
 

SqlConnection(ConfigurationManager.ConnectionStrings["Northwind"].ConnectionString);
 
            try
            {
                SqlCommand cmd = new SqlCommand();
                cmd.CommandText = "[GetOrderDetailsTotalByProductID]";
                cmd.Connection = conn;
 
                cmd.CommandType = CommandType.StoredProcedure;
 
                cmd.Parameters.Add("@ProductID", SqlDbType.Int, 4).Value = 21;
                cmd.Parameters.Add("@Total", SqlDbType.Money).Direction = ParameterDirection.Output;
 
                conn.Open();
                cmd.ExecuteNonQuery();
 
                lblTotal.Text = cmd.Parameters["@Total"].Value.ToString();
            }
            catch (SqlException ex)
            {
                throw new Exception(ex.Message, ex);
            }
            finally
            {
                conn.Close();
            }

4、Return 返回值

使用返回值表示存儲過程的執行狀態，它類似於輸出參數，其區別：

(1)、返回值只能返回sql整數值；

(2)、返回值不能在存儲過程內部聲明，它使用Transcat-SQL的RETURN語句返回；

CREATE PROC [DBO].[GetOrdersByCustomerID]
    @CustomerID INT,
    @OrderDate DATETIME OUTPUT
AS
    SELECT @OrderDate = MAX([OrderDate])
    FROM
        [Orders]
    WHERE
        [CustomerID] = @CustomerID
 
    IF @OrderDate IS NULL
        RETURN 0
    ELSE
        RETURN 1
　

SqlConnection(ConfigurationManager.ConnectionStrings["Northwind"].ConnectionString);
 
            try
            {
                SqlCommand cmd = new SqlCommand();
                cmd.CommandText = "[GetOrdersByEmployeeID]";
                cmd.Connection = conn;
 
                cmd.CommandType = CommandType.StoredProcedure;
 
                cmd.Parameters.Add("@ReturnValue", SqlDbType.Int, 4).Direction = ParameterDirection.ReturnValue;
                cmd.Parameters.Add("@EmployeeID", SqlDbType.Int, 4).Value = 1;
                cmd.Parameters.Add("@OrderDate", SqlDbType.DateTime).Direction = ParameterDirection.Output;
 
                conn.Open();
                cmd.ExecuteNonQuery();
 
                lblReturnValue.Text = cmd.Parameters["@ReturnValue"].Value.ToString();
                lblOrderDate.Text = cmd.Parameters["@OrderDate"].Value.ToString();
            }
            catch (SqlException ex)
            {
                throw new Exception(ex.Message, ex);
            }
            finally
            {
                conn.Close();
            }