ASP.NET C＃を使用してセッション変数にSQLクエリの結果を格納する方法

Question

私はASP.NET C＃を初めて使用しています。メッセージを送受信するためのWebフォームの開発に取り組んでいます。電子メールのように。私はSQLクエリの結果をセッション変数に保存し、後で別のページで使用したいと思います。

どうすればいいのですか。何か問題が生じた場合は、どうか修正してください。あなたはあなたを返します。このメソッドにそのクエリを渡す必要が

SqlConnection con = new SqlConnection("Data Source=AZEEM\\SQLEXPRESS; Initial Catalog=kics;User ID=sa;Password=123"); 
con.Open(); 

String query = "select username as sender,subject,message from emailtable where receiver='" + Session["username"] + "'"; 

    enter code here 

//this is the query for which I want to store the result in variable myvar, how can I store the result of following query in variable myvar and use it later, when I execute it, string is shown instead of result of string. 
String myvar = "select receiver from emailtable where username='" + Session["username"] + "'"; 
SqlDataReader reader = null; 

SqlCommand cmd = new SqlCommand(query, con); 
SqlCommand cmd2 = new SqlCommand(myvar, con); 

DataTable dt = new DataTable(); 
SqlDataAdapter sda = new SqlDataAdapter(cmd); 
sda.Fill(dt); 
reader = cmd2.ExecuteReader(); 

GridView1.DataSource = dt; 
GridView1.DataBind(); 
DataSet ds = new DataSet(); 

ds = myvar; 

Answer 1

以下試してみてください、あなたが取得

SqlConnection con = new SqlConnection("Data Source=AZEEM\\SQLEXPRESS; Initial Catalog=kics;User ID=sa;Password=123"); 
con.Open(); 

String query = "select username as sender,subject,message from emailtable where receiver='" + Session["username"] + "'"; 

    enter code here 

//this is the query for which I want to store the result in variable myvar, how can I store the result of following query in variable myvar and use it later, when I execute it, string is shown instead of result of string. 
String myvar = "select receiver from emailtable where username='" + Session["username"] + "'"; 
SqlDataReader reader = null; 

SqlCommand cmd = new SqlCommand(query, con); 
SqlCommand cmd2 = new SqlCommand(myvar, con); 

DataTable dt = new DataTable(); 
SqlDataAdapter sda = new SqlDataAdapter(cmd); 
sda.Fill(dt); 
reader = cmd2.ExecuteReader(); 

GridView1.DataSource = dt; 
GridView1.DataBind(); 

session["dt"] = dt; 

、

if (session["dt"] != null) { 
    DataTable dt = (DataTable)session["dt"]; 
} 

Answer 2

：ここ

は私のコードです結果をSetしてセッションに割り当てようとする

実際にあなたのQSTあるwhiat GetDataのため

String myvar = "select receiver from emailtable where username='" + Session["username"] + "'"; 
    Session["myvar"] = GetData(myvar); 

方法

private static DataTable GetData(string query) 
     { 
      DataTable dt = new DataTable(); 
      string constr = "Data Source=AZEEM\\SQLEXPRESS; Initial Catalog=kics;User ID=sa;Password=123"; 
      using (SqlConnection con = new SqlConnection(constr)) 
      { 
       using (SqlCommand cmd = new SqlCommand(query)) 
       { 
        using (SqlDataAdapter sda = new SqlDataAdapter()) 
        { 
         cmd.CommandType = CommandType.Text; 
         cmd.Connection = con; 
         sda.SelectCommand = cmd; 
         sda.Fill(dt); 

        } 
       } 
       return dt; 
      } 
     }