如何将数据库行绑定到标签？ [英] How to bind database rows to the label?

问题描述

Hai Sir，

我有一个名为Subject的表和两个SubId，SubName和Year列。在此表中，我根据年份添加了多个主题名称。



从这里开始，在前端设计中有一个下拉列表，其中包含来自数据库的主题表的绑定年份行。当我选择特定年份时，主题名称应仅以标签形式出现。



如何为此要求编写代码？

解决方案

可能会帮助你.Onselectindexchange事件的下拉列表

  using （SqlCommand cmd =  new  SqlCommand（  select * from tablename where year =' + dropdownlist.SelectedValue +  '，CONN））
 {
 cmd.ExecuteNonQuery（）; 
 使用（SqlDataAdapter sqd =  new  SqlDataAdapter（cmd））
 {
 DataTable dtq =  new  DataTable（）; 
 sqd.Fill（dtq）; 
  if （dtq.Rows.Count >   0 ）
 {
  for （ int  i = < span class =code-digit> 0 ; i <  dtq.Rows.Count; i ++）
 {
 < span class =code-keyword> if （lbltext.Text！=   ） //   lbltext是Label的ID  
 {
 lbltext.Text = lbltext.Text +  ， + dtq.Rows [i] [  name]。ToString（）; 
} 
  else  
 {
 lbltext.Text = dtq.Rows [i] [  name]。ToString（）; 
} 
} 
} 
 
} 
} 

C＃

 受保护  void  Page_Load（ object  sender，EventArgs e）
 {
  if （！IsPostBack）
 {
 使用（DBEntities dc =  new  DBEntities （））
 {
 ddlYear.DataSource = dc.Subjects.Select（s = >  s.Year）.Distinct（）。ToList （）; 
 ddlYear.DataBind（）; 
} 
} 
} 
 
 受保护  void  ddlYear_SelectedIndexChanged（ object  sender，EventArgs e）
 {
  int  year = Convert.ToInt32（ddlYear.Text）; 
 使用（DBEntities dc =  new  DBEntities（））
 {
 ListViewSubjects.DataSource = dc.Subjects.Where（s = >  s.Year == year）.Distinct（）。ToList（）; 
 ListViewSubjects.DataBind（）; 
} 
} 

ASPX

 <   form     id   =  form1    runat   = 服务器 >  
 <   div  >  
 <   asp：DropDownList     ID   =  ddlYear    runat   =  server    AutoPostBack   =  True    OnSelectedIndexChanged   =  ddlYear_SelectedIndexChanged >  <   / asp：DropDownList  >  
 <   br     /  >  
 <   asp：ListView     ID   =  ListViewSubjects    runat   =  server >  
 <   ItemTemplate  >  
 <   asp：标签    ID   =  NameLabel    runat   = 服务器  
   
                      文字  = '  <％ #Eval（ 名称）％> '    /  >  
 <   / ItemTemplate  >  
  <   / asp：ListView  >  
 <   / div  >  
 <   / form   >  

Hai Sir,
I have one table with name Subject and two columns SubId,SubName and Year .In this table I added multiple subject names based on year.

From this, in front end design there is a dropdown list having binding Year rows from Subject Table from Database. When I select particular year the subject names should come in Labels only.

How can I write code for this requirement?

解决方案

May be this will help you out.Onselectindexchange event of drop-downlist

using (SqlCommand cmd = new SqlCommand("select * from tablename where year='"+dropdownlist.SelectedValue+"'", CONN)) 
            {
                cmd.ExecuteNonQuery();
                using (SqlDataAdapter sqd = new SqlDataAdapter(cmd))
                {
                    DataTable dtq = new DataTable();
                    sqd.Fill(dtq);
                    if (dtq.Rows.Count > 0)
                    {
                        for (int i = 0; i < dtq.Rows.Count; i++)
                        {
                            if (lbltext.Text != "")// lbltext is the id of Label
                            {
                                lbltext.Text = lbltext.Text + ", " + dtq.Rows[i]["name"].ToString();
                            }
                            else
                            {
                                lbltext.Text = dtq.Rows[i]["name"].ToString();
                            }
                        }
                    }

                }
            }

C#

protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                using (DBEntities dc = new DBEntities())
                {
                    ddlYear.DataSource = dc.Subjects.Select(s => s.Year).Distinct().ToList();
                    ddlYear.DataBind();
                }
            }
        }

        protected void ddlYear_SelectedIndexChanged(object sender, EventArgs e)
        {
            int year = Convert.ToInt32(ddlYear.Text);
            using (DBEntities dc = new DBEntities())
            {
                ListViewSubjects.DataSource = dc.Subjects.Where(s=> s.Year == year) .Distinct().ToList();
                ListViewSubjects.DataBind();
            }
        }

ASPX

<form id="form1" runat="server">
    <div>
        <asp:DropDownList ID="ddlYear" runat="server" AutoPostBack="True" OnSelectedIndexChanged="ddlYear_SelectedIndexChanged"></asp:DropDownList>
        <br />
        <asp:ListView ID="ListViewSubjects" runat="server">
            <ItemTemplate>
                  <asp:Label ID="NameLabel" runat="server"

          Text='<%#Eval("Name") %>' />
            </ItemTemplate>
        </asp:ListView>
    </div>
    </form>

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