下拉列表不显示数据库值 [英] dropdownlist not appearing database values
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问题描述
您好我使用内部联接从数据库中获取我的值,我希望它出现在我的下拉列表中,但为什么我的下拉列表没有来自数据库的值,这是我的代码。
if (!IsPostBack) // aspx.cs
{
ListItem> allrID = new 列表< item>();
allID = diBLL.rID();
ddl_ID.DataSource = allID;
ddl_ID.DataBind();
ddl_ID.Items.Insert( 0 , new ListItem( - 选择 - , 0跨度>));
}
// aspxID:< ; asp:DropDownList ID =ddl_IDrunat =serverDataTextField =IDDataValueField =ID
// sql
public 列表< item> getrID()
{
List< item> IDAll = new 列表< tem>();
int ID;
string queryStr = 选择Item.ID FROM Item JOIN Food on Item.ID = FoodID;
SqlConnection conn = new SqlConnection(_connStr);
SqlCommand cmd = new SqlCommand(queryStr,conn);
conn.Open();
SqlDataReader dr = cmd.ExecuteReader();
while (dr.Read())
{
string id = dr [ Food.ID]。ToString();
ID = int .Parse(id);
IDAll.Add( new Item(ID));
}
conn.Close();
dr.Close();
dr.Dispose();
return IDAll;
}
解决方案
试试这个
public 列表< item> getrID()
{
List< item> IDAll = new 列表< item>();
int ID;
string queryStr = 选择Item.ID FROM Item JOIN Food on Item.ID = Food.ID;
SqlConnection conn = new SqlConnection(_connStr);
SqlCommand cmd = new SqlCommand(queryStr,conn);
conn.Open();
SqlDataReader dr = cmd.ExecuteReader();
while (dr.Read())
{
string id = dr [ ID]。ToString();
ID = int .Parse(id);
IDAll.Add( new Item(ID));
}
conn.Close();
dr.Close();
dr.Dispose();
return IDAll;
} < / item > < / item > ; < / item > < /跨度>
Hi I have use inner join to get my values from database, I want it to appear in my dropdownlist, but why my dropdownlist do not have the values from database , here is my code.
if (!IsPostBack) //aspx.cs
{
ListItem> allrID = new List<item>();
allID = diBLL.rID();
ddl_ID.DataSource = allID;
ddl_ID.DataBind();
ddl_ID.Items.Insert(0, new ListItem("--Select--", "0"));
}
//aspxID :<asp:DropDownList ID="ddl_ID" runat="server" DataTextField="ID" DataValueField="ID"
//sql
public List<item> getrID()
{
List<item> IDAll = new List<tem>();
int ID;
string queryStr = "Select Item.ID FROM Item JOIN Food on Item.ID= FoodID ";
SqlConnection conn = new SqlConnection(_connStr);
SqlCommand cmd = new SqlCommand(queryStr, conn);
conn.Open();
SqlDataReader dr = cmd.ExecuteReader();
while (dr.Read())
{
string id = dr["Food.ID"].ToString();
ID = int.Parse(id);
IDAll.Add(new Item (ID));
}
conn.Close();
dr.Close();
dr.Dispose();
return IDAll;
}
解决方案
Try this
public List<item> getrID() { List<item> IDAll = new List<item>(); int ID; string queryStr = "Select Item.ID FROM Item JOIN Food on Item.ID= Food.ID "; SqlConnection conn = new SqlConnection(_connStr); SqlCommand cmd = new SqlCommand(queryStr, conn); conn.Open(); SqlDataReader dr = cmd.ExecuteReader(); while (dr.Read()) { string id = dr["ID"].ToString(); ID = int.Parse(id); IDAll.Add(new Item (ID)); } conn.Close(); dr.Close(); dr.Dispose(); return IDAll; }</item></item></item>
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