由于代码显示多个记录 [英] Multiple records displayed due to code

问题描述

文本被添加到数据库并显示，但它显示了多个记录，并且它们没有按顺序降序。我在页面上显示了两组记录，插入的文本被下推到第一个多记录的底部。

我怎样才能纠正这个问题，所以我
$ b

代码：

pre> protected void Page_Load（object sender，EventArgs e）
{
string theUserId = Session [UserID]。ToString（）;
PopulateWallPosts（theUserId）;
}
private void PopulateWallPosts（string userId）
{

using（OdbcConnection cn = new OdbcConnection（Driver = {MySQL ODBC 3.51 Driver}; Server = localhost ; Database = gymwebsite2; User = x; Password = x;））
{
cn.Open（）;
using（OdbcCommand cmd = new OdbcCommand（SELECT Wallpostings FROM WallPosting WHERE UserID =+ userId +ORDER BY idWallPosting DESC，cn））
{
using（OdbcDataReader reader = cmd。 ExecuteReader（））
{



while（reader.Read（））
{
System.Web.UI.HtmlControls。 HtmlGenericControl div = new System.Web.UI.HtmlControls.HtmlGenericControl（div）;
div.Style [float] =left;
Image img = new Image（）;
img.ImageUrl =〜/ userdata / 2 / uploadedimage / batman-for-facebook.jpg;
img.AlternateText =测试图片;
div.Controls.Add（img）;
test1.Controls.Add（div）;

System.Web.UI.HtmlControls.HtmlGenericControl div1 = new System.Web.UI.HtmlControls.HtmlGenericControl（div）;
div1.InnerText = String.Format（{0}，reader.GetString（0））;

div1.Style [float] =left;
test1.Controls.Add（div1）;

System.Web.UI.HtmlControls.HtmlGenericControl div2 = new System.Web.UI.HtmlControls.HtmlGenericControl（div）;
div2.Style [clear] =both;
test1.Controls.Add（div2）;
}
}
}
}
}








protected void Button1_Click（object sender，EventArgs e）
{
string theUserId = Session [UserID]。ToString（）;
using（OdbcConnection cn = new OdbcConnection（Driver = {MySQL ODBC 3.51 Driver}; Server = localhost; Database = gymwebsite2; User = x; Password = x;））
{
cn.Open（）;
using（OdbcCommand cmd = new OdbcCommand（INSERT INTO WallPosting（UserID，Wallpostings）VALUES（+ theUserId +，'+ TextBox1.Text +'），cn））
{
cmd.ExecuteNonQuery（）;
}
}
PopulateWallPosts（theUserId）;


$ / code>

解决方案

清除循环前的占位符控件：

  test1.Controls.Clear（）; 
 while（reader.Read（））
 {
 ... 
} 
  

Hello Im getting multiple records displayed and they arent descending in order correctly when I insert on button click.

The text is added to the database and it is displayed but I get two sets of records displayed on the page and the text from the insert is pushed down to the bottom of the first multiple record.

How can I correct this so I only get one return on the page and the comment(text from db) is set to desc.

Code:

   protected void Page_Load(object sender, EventArgs e)
    {
        string theUserId = Session["UserID"].ToString();
        PopulateWallPosts(theUserId);
    }
    private void PopulateWallPosts(string userId)
    {

        using (OdbcConnection cn = new OdbcConnection("Driver={MySQL ODBC 3.51 Driver}; Server=localhost; Database=gymwebsite2; User=x; Password=x;"))
        {
            cn.Open();
            using (OdbcCommand cmd = new OdbcCommand("SELECT Wallpostings FROM WallPosting WHERE UserID=" + userId + " ORDER BY idWallPosting DESC", cn))
            {
                using (OdbcDataReader reader = cmd.ExecuteReader())
                {



                    while (reader.Read())
                    {
                        System.Web.UI.HtmlControls.HtmlGenericControl div = new System.Web.UI.HtmlControls.HtmlGenericControl("div");
                        div.Style["float"] = "left";
                        Image img = new Image();
                        img.ImageUrl = "~/userdata/2/uploadedimage/batman-for-facebook.jpg";
                        img.AlternateText = "Test image";
                        div.Controls.Add(img);
                        test1.Controls.Add(div);

                        System.Web.UI.HtmlControls.HtmlGenericControl div1 = new System.Web.UI.HtmlControls.HtmlGenericControl("div");
                        div1.InnerText = String.Format("{0}", reader.GetString(0));

                        div1.Style["float"] = "left";
                        test1.Controls.Add(div1);

                        System.Web.UI.HtmlControls.HtmlGenericControl div2 = new System.Web.UI.HtmlControls.HtmlGenericControl("div");
                        div2.Style["clear"] = "both";
                        test1.Controls.Add(div2);
                    }
                }
            }
        }
    }








    protected void Button1_Click(object sender, EventArgs e)
    {
        string theUserId = Session["UserID"].ToString();
        using (OdbcConnection cn = new OdbcConnection("Driver={MySQL ODBC 3.51 Driver}; Server=localhost; Database=gymwebsite2; User=x; Password=x;"))
        {
            cn.Open();
            using (OdbcCommand cmd = new OdbcCommand("INSERT INTO WallPosting (UserID, Wallpostings) VALUES (" + theUserId + ", '" + TextBox1.Text + "')", cn))
            {
                cmd.ExecuteNonQuery();
            }
        }
        PopulateWallPosts(theUserId);
    }
}

解决方案

Simply clear the placeholder control before the loop:

test1.Controls.Clear();
while (reader.Read())
{
   ...
}

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