ASP.NET C# 从数据库中检索多个值并添加到会话中答案

【问题标题】：ASP.NET C# retrieve multiple value from database and add in sessionASP.NET C# 从数据库中检索多个值并添加到会话中
【发布时间】：2019-06-01 04:17:21
【问题描述】：

如何从 SQL Server 数据库中添加多个列值并插入session[]？

只是 FirstName 正在工作，当我添加 LastName 时，我收到一个错误。

string constr = sql connection here.... ;

using (SqlConnection con = new SqlConnection(constr))
{
    using (SqlCommand cmd = new SqlCommand("SELECT Email, [FirstName] FROM Personal WHERE Email = @email"), cmd2 = new SqlCommand("SELECT Email, [LastName] FROM Personal WHERE Email = @email"))
    {
        cmd.Parameters.AddWithValue("@email", TextboxUsr.Text);
        cmd.Connection = con;
        cmd2.Parameters.AddWithValue("@email", TextboxUsr.Text);
        cmd2.Connection = con;

        con.Open();

        using (SqlDataReader sdr = cmd.ExecuteReader())
        {
            if (sdr.Read())
            {
                string fName = sdr["FirstName"].ToString();
                //string lName = sdr["LastName"].ToString();

                string userFullName = fName;
                Session["New"] = userFullName;
            }
        }

        //con.Close();
    }
}

【问题讨论】：

I add LastName is given error. 什么错误？您是否注意到cmd 没有选择LastName？为什么你有cmd 和cmd2？

标签： c# asp.net sql-server webforms

【解决方案1】：

步骤 01：阅读有关 SQL 和 C# 基础的更多信息

您需要阅读更多内容

步骤02：正确使用Select

改变

SqlCommand 
cmd = new SqlCommand("SELECT Email, [FirstName] FROM Personal WHERE Email = @email"), 
cmd2 = new SqlCommand("SELECT Email, [LastName] FROM Personal WHERE Email = @email"))

到

SqlCommand 
cmd = new SqlCommand("SELECT Email, [FirstName],[LastName] FROM Personal WHERE Email = @email")

步骤03：阅读完整代码

var sql = @"SELECT Email, [FirstName],[LastName] FROM Personal WHERE Email = @email";
using (var con = new SqlConnection(constr))
using (var cmd = new SqlCommand(sql, con))
{
    con.Open();
    cmd.Parameters.AddWithValue("@email", TextboxUsr.Text);
    using (var sdr = cmd.ExecuteReader())
    {
        if (sdr.Read())
        {
            var fName = sdr["FirstName"].ToString();
            var lName = sdr["LastName"].ToString();
            var userFullName = fName + " " + lName;
            Session["New"] = userFullName;
        }
    }
}

【讨论】：

还需要帮助吗？