急求SQL问题解答。。。

[W578439331W]

怎样用一个新的字符串来接收执行下面这个sql字符串的返回值？

string sql = "select pretime from preInfo where stuNum='" + textBox1.Text + "' ";

急求，谢了。。。

[心灵彩虹]

这不是已经实现了，不明白楼猪意思。

[子夜__]

protected void Page_Load(object sender, EventArgs e)
    {
        string sql = "select pretime from preInfo where stuNum='" + textBox1.Text + "' ";
        Response.Write(ReturnDataTable(sql).Rows[0][0].ToString());
    }


    public static DataTable ReturnDataTable(string cmdtext)
    {
        SqlConnection cn = new SqlConnection();
        cn.ConnectionString = "数据库连接字符串";
        DataTable dt = new DataTable();
        SqlCommand cmd = new SqlCommand();
        cmd = new SqlCommand(cmdtext, cn);
        cmd.CommandType = CommandType.Text; ;
        SqlDataReader dr = null;
        using (dr = cmd.ExecuteReader(CommandBehavior.CloseConnection))
        {
            dt.Load(dr);
        }
        return dt;
    }

[挨踢直男]

遍历返回的记录集，拼接字符串