Question

我需要从数据库中获取6个值并将它们绑定到链接按钮文本，她是代码

public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        //string post = Request.QueryString["post"];
        ////string title = "nokia";

        string date = DateTime.Now.ToShortDateString();
        SqlConnection conn = new SqlConnection(); 

        conn.ConnectionString = @"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\nokiaoaq\Desktop\WebSite1\App_Data\Database.mdf;Integrated Security=True;User Instance=True";
        try
        {
            conn.Open();
            //string str = "insert into Table1 (title , date_ ,www, cat) values  (' " + TextBox1.Text + "','" + DateTime.Now.ToShortDateString() + "','" + TextBox2.Text + "','" + DropDownList1.SelectedItem.Text + "')";
            ////string str = "INSERT INTO Table1  (title,date_,www ) values ('ddddddd','aaaaaaa','qqqqqq')";


            string str =
                //"SELECT   from table1  WHERE  cat = 1 and datee='" + date + "'ORDER BY datee";
            "SELECT table1.title  FROM table1 WHERE cat = 1 and datee='" + date + "'ORDER BY datee DESC";

            SqlCommand objcmd = new SqlCommand(str, conn);
            SqlDataAdapter da1 = new SqlDataAdapter(objcmd);
            DataTable dt = new DataTable();
            da1.Fill(dt);

            //DataRow dr = new DataRow();
            //DataRow dr = ds.Tables[0].Rows[0];

            foreach (DataRow dr in dt.Rows)
            {
                ml1.Text = dr[0].ToString();
                ml2.Text = dr[1].ToString();
                ml3.Text = dr[2].ToString();
                ml4.Text = dr[3].ToString();
                ml5.Text = dr[4].ToString();
                ml6.Text = dr[5].ToString();
            }
        }
        catch (Exception ex)
        {
            Label4.Text = "Failed to connect to data source";
        }
        finally
        {
            conn.Close();
        }
    }
}

ml是链接按钮ID

Answer 1

您正尝试将返回的行中的6个字段分配给6个不同的文本框，但您的选择查询只会询问一个字段。如果要返回多个字段，请将其名称添加到选择查询中（将fieldX更改为相应的字段名称）。

string str = "SELECT title, field1, field2, field3, field4, field5  " + 
             "FROM table1 WHERE cat = 1 and datee=@dt ORDER BY datee DESC";

也不要使用字符串连接来构建sql语句。始终使用参数化查询

SqlCommand objcmd = new SqlCommand(str, conn);
objcmd.Parameters.AddWithValue("@dt", datee);
.....

这样可以避免格式化字符串，日期，数字等问题，还可以避免sql注入问题。

顺便说一下，我希望你的代码只返回一行，因为就现在而言，如果你有多行返回，那么只有具有最早日期的那一行才会显示在文本框中。（如果是这种情况，则订单无用）。如果您返回了多行，则应考虑将数据表绑定到GridView以显示返回的所有记录。

我需要从数据库sql中获取多个值

1 个答案: