C# C将两个Mysql列名合并为一个

在C Asp.net中，我试图将两列数据合并为一列并显示在下拉列表中，但当我无法这样做时，显示为DD_TName1.DataTextField=FirstName+“”+LastName；问题是hear，控制台错误是

Sys.WebForms.PageRequestManagerServerErrorException:Sys.WebForms.PageRequestManagerServerErrorException:DataBinding:“System.Data.Common.DataRecordInternal”不包含名为“FirstName LastName”的属性

根据控制台错误，db将要转换为字符串的列名作为一个列名读取

using (MySqlConnection con = new MySqlConnection(constr))
        {
            using (MySqlCommand cmd = new MySqlCommand("SELECT * from euser_teacher WHERE SchoolId='" + Schoolid + "' and StaffType='Teaching' and IsDeleted='0'  order by FirstName     ASC"))
            {

                cmd.CommandType = CommandType.Text;
                cmd.Connection = con;
                con.Open();
                DD_TName1.DataSource = cmd.ExecuteReader();


                DD_TName1.DataTextField = "FirstName" + ' ' + "LastName";
                DD_TName1.DataValueField = "TeacherId";
                DD_TName1.DataBind();
                con.Close();
            }
        }

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修改SELECT语句怎么样

mySQL：

SELECT TeacherId, Concat(FirstName, ' ',LastName) AS FirstLast from euser_teacher WHERE

C

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尝试将sql从select*更改为select FirstName，LastNamefieldname（根据需要）

你应该清楚地提到它，同意Rakin修改了你的代码，但他更具体地说：干杯

DD_TName1.DataTextField = "FirstLast";
DD_TName1.DataValueField = "TeacherId";