这是我尝试做的事情
在 button_click 上，我从文本框中读取值并将它们插入到数据库中。作为旅游人数，例如可能有两个或三个使用 ExecuteScalar 的游客；我得到了插入的游客的身份证！
公共无效cmdInsert_OnClick（对象发送者，EventArgs e）{
if (Page.IsValid)
{
string numtourist = (string)Session["tourist_number"];
for (int i = 0; i < Int32.Parse(numtourist); i++)
{
TextBox tx888 = (TextBox)FindControl("txtNameK" + i.ToString());
TextBox tx888_1 = (TextBox)FindControl("txtMidNameK" + i.ToString());
TextBox tx888_2 = (TextBox)FindControl("txtLastNameK" + i.ToString());
string insertSQL = "INSERT INTO Tourist (Excursion_ID, Excursion_date_ID, Name_kir,Midname_kir, Lastname_kir)";
insertSQL += " VALUES (@Excursion_ID, @Excursion_date_ID, @Name_kir,@Midname_kir, @Lastname_kir) SELECT @@IDENTITY";
string connectionString = "Data Source = localhost\\SQLExpress;Initial Catalog=excursion;Integrated Security=SSPI";
SqlConnection con = new SqlConnection(connectionString);
SqlCommand cmd = new SqlCommand(insertSQL, con);
cmd.Parameters.AddWithValue("@Excursion_ID", Convert.ToInt32(mynew2));
cmd.Parameters.AddWithValue("@Excursion_date_ID", Convert.ToInt32(mynewnewstring));
cmd.Parameters.AddWithValue("@Name_kir", tx888.Text);
cmd.Parameters.AddWithValue("@MidName_kir", tx888_1.Text);
cmd.Parameters.AddWithValue("@LastName_kir", tx888_2.Text);
int added;
try
{
con.Open();
added = (int)cmd.ExecuteScalar();
lblproba.Text = "";
Tourist.Add(added);
lblproba.Text += Tourist.Count();
}
catch (Exception ex)
{
lblproba.Text += ex.Message;
}
finally
{
con.Close();
}
}
createReservation();
}
}
我调用 CreateReservationFunction 并使用已进行预订的用户的 ID 创建一个新的预订。使用 SELECT IDENTITY 我尝试获取预留的 RESERVATION_ID，在这里我得到异常“无法评估表达式，因为代码已优化或本机框架位于调用堆栈顶部”。所以我想知道这个异常是否与以下事实有共同之处,net 但实体框架
公共无效createReservation（）{
string insertSQL = "Insert INTO RESERVATIONS (User_ID) values (@User_ID) SELECT @@IDENTITY";
string connectionString = "Data Source = localhost\\SQLExpress;Initial Catalog=excursion;Integrated Security=SSPI";
SqlConnection con = new SqlConnection(connectionString);
SqlCommand cmd = new SqlCommand(insertSQL, con);
cmd.Parameters.AddWithValue("@User_ID", 9);
try
{
con.Open();
string added = cmd.ExecuteScalar().ToString();
createTouristReservation(added);
}
catch (Exception ex)
{
lblproba.Text+= ex.Message;
}
}