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[英]How to read data from database and store it in array using linq to sql?
[英]how to store items from database inside an array?
public partial class Piechart : System.Web.UI.Page
{
private decimal total = 0; // course total
private decimal registered = 0;
private decimal regAttend = 0;
private decimal nRegAttend = 0;
private int regPer = 0;
private int regToTotalPer = 0;
private int nRegPer = 0;
private int angle = 0;
private int angle2 = 0;
private int angle3 = 0;
private int parTotal = 0;
//const string G = "SELECT DISTINCT COUNT(Grouping) from Attendance";
// SqlConnection c = new SqlConnection(@"Data Source=localhost\SQLEXPRESS;Initial Catalog=PSeminar;Integrated Security=true;Trusted_Connection=Yes;MultipleActiveResultSets=true");
//SqlCommand Command = new SqlCommand(G);
private string[] Status = new string[2] { "Attend", "Didn't Attend" };
private string[] Course = new string[] {//items from database};
我想使用sql語句調用項目列表並存儲在上述數組中。 我這樣做是因為以前數組中的項目都是硬編碼的。 現在,我想從數據庫中檢索它,因為只要有新項目,就會自動繪制一個新的餅圖。
這是使用ArrayList
做到這一點的方法
ArrayList Course = new ArrayList();
const string query = "SELECT DISTINCT COUNT(Grouping) from Attendance";
const string connectionString = @"Data Source=localhost\SQLEXPRESS;Initial Catalog=PSeminar;Integrated Security=true;Trusted_Connection=Yes;MultipleActiveResultSets=true";
using (SqlConnection cn = new SqlConnection(connectionString))
{
using (SqlCommand cm = new SqlCommand(query, cn))
{
cn.Open();
SqlDataReader reader = cm.ExecuteReader();
while (reader.Read())
{
Course.Add(reader.GetString(0));
}
}
}
//Course.ToArray(); // <-- cast to string array object do use in the pie chart
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