C#中的存储过程

Question

我想在c#中使用存储过程.我在sql server中创建存储过程,然后在程序中调用它.但是当我使用断点功能时,我才知道,当断点跳过循环时,数据不会从数据库中检索出来.

.aspx代码:

<asp:Button ID="Button1" runat="server" Text="Button" OnClick="store" />
<asp:Label ID="Label9" runat="server" Text="Label"></asp:Label>

c#代码:

public void store(object sender, EventArgs ser)
{
    try
    {
        // c reate and open a connection object
        SqlConnection conn = Class3.GetConnection();

        // 1. create a command object identifying the stored procedure
        SqlCommand cmd = new SqlCommand("storeprocedure3", conn);

        // 2. set the command object so it knows to execute a stored procedure
        cmd.CommandType = CommandType.StoredProcedure;

        // 3. add parameter to command, which will be execute the command
        SqlDataReader rdr = cmd.ExecuteReader();

        // iterate through results, printing each to console
        while (rdr.Read())
        {
            Label9.Text = rdr["menuename"].ToString();
        }
    }
    catch (Exception sa)
    {
        Console.WriteLine(sa);
    }
}

存储过程:

CREATE PROCEDURE procedure3     
AS
BEGIN
    select menuename from menue;

END
GO

Answer 1

你的程序不匹配(procedure3 vs storeprocedure3)

使用此代码

 SqlCommand cmd = new SqlCommand("procedure3 ", conn);

并关闭你的连接

 SqlDataReader rdr = cmd.ExecuteReader(CommandBehavior.CloseConnection);

Answer 2

IMO,这是最大和最可能的问题:

catch (Exception sa)
{
    Console.WriteLine(sa);
}

我想象它正试图真的很难告诉你什么是错的,但是你沉默了.没有任何理由来try/ catch本; 如果这不起作用,那就是非常错误 - 让它出错.阅读例外细节.

如果我挑剔(坦白说,我是) - 你在这里需要更多using,即

using(SqlConnection conn = Class3.GetConnection())
using(SqlCommand cmd = new SqlCommand("whatever", conn))
{
    cmd.CommandType = CommandType.StoredProcedure;
    using(SqlDataReader rdr = cmd.ExecuteReader())
    {
        while (rdr.Read())
        {
           // do something
        }
    }
}

或者,坦率地说,使用像小巧玲珑的工具:

using(SqlConnection conn = Class3.GetConnection())
{
    foreach(var obj in conn.Query("whatever",
          commandType: CommandType.StoredProcedure))
    {
        string menuename = obj.menuename;
        // do something...
    }
}