连接数据库

 

public class DBQuery
{
    static SqlConnection con = DBconnection.getcon();
    static DataTable dt;
    public DBQuery()
    {
        //
        // TODO: 在此处添加构造函数逻辑
        //
    }

    public static DataTable OpenQuery(string sql)
    {
        SqlDataAdapter sda = new SqlDataAdapter(sql,con);
        dt = new DataTable();
        /*try
        {
            sda.Fill(dt);
        }
        catch (Exception ex)
        {
            throw ex;
        }
        finally
        {
            sda.Dispose();
        }*/
        sda.Fill(dt);
        return dt;
    }
}

 

using System;
using System.Web;
using System.Web.Caching;
using System.Data.SqlClient ;

  public class DBConnection
 {
       public DBConnection()
       {
        }

        public static string getConnStr()
       {
               if(HttpContext.Current.Cache["conn"]==null)
              {
                     HttpContext.Current.Cache.Insert("conn", "Data Source=.;Initial Catalog=fy;Persist Security Info=True;User ID=sa;password=sa");  
               }
              return HttpContext.Current.Cache["conn"].ToString();
        }

         public static SqlConnection  getConn()
        {
              return new SqlConnection (getConnStr());
         }

}