如何知道行值sql server asp.net？

Question

我張貼這幾天前How to know a row's value before its inserted in gridview? 和我得到這個答案

SqlCommand cmdEvent = new SqlCommand("SELECT COUNT(date) FROM patients WHERE date= '2012/02/23'", yourSqlConnection); 
object myCount; 
if (yourSqlConnection.State == ConnectionState.Closed){ yourSqlConnection.Open(); } 
myCount = cmdEvent.ExecuteScalar(); 
if (yourSqlConnection.State == ConnectionState.Open){ yourSqlConnection.Close(); } 

if (myCount != null) 
{ 
    if ((int)myCount >= 10) 
    { 
    // Logic here e.g myLabel.Text = "You have reached your maximum of 10 visits!"; 
    return; 
    } 
} 

但現在我不需要一個行的值之前其插入，相反，我需要了解的2行中的值，我沒有如何去做的想法。 我試着做一個登錄名和我需要的用戶的ID進行會話獨一無二的，但我也需要驗證，如果該查詢返回true，我做了如下：

comando = new SqlCommand("SELECT user_name FROM login WHERE user_name=@user AND pass=@pass", conexion); 
comando.Parameters.AddWithValue("@pass", Upass); 
comando.Parameters.AddWithValue("@user", user); 
object check_coincidence = comando.ExecuteScalar(); 

if ((string)check_coincidence == user) 
{ 
    Session["USER"] = check_coincidence; 
    Response.Redirect("someURL") 
} 

但我不知道如何gat用戶的ID以使會話具有唯一性，我的意思是，將該值作爲新會話。

Answer 1

要從查詢中獲得更多結果，您必須使用SqlReader。

comando = new SqlCommand("SELECT user_name, user_id FROM login WHERE user_name=@user AND pass=@pass", conexion); 
comando.Parameters.AddWithValue("@pass", Upass); 
comando.Parameters.AddWithValue("@user", user); 

SqlDataReader reader = commando.ExecuteReader(); 
     while (reader.Read()) 
     { 
      var userName = Convert.ToString(reader["user_name"]); 
      var userId = Convert.ToInt32(reader["user_id"]); 
     } 

我會建議遵循一些教程，這將有助於理解Sql類。檢查這個例如：http://csharp-station.com/Tutorials/AdoDotNet/Lesson03.aspx