//获取连接字符串，在未引用System.Configuration时可以手动拼写引用
//private static string _connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["StockDB"].ConnectionString;
private static string _connectionString = ConfigurationManager.ConnectionStrings["StockDB"].ConnectionString;
SqlConnection conn = null;
SqlCommand cmd = null;
public AllocationBusiness() 
{
   conn = new SqlConnection(_connectionString);
   cmd = conn.CreateCommand();
}

//通用数据库访问类
//strconn为获取的连接字符串
Utilities.DbUtility.DbAccess DBdataStatistics = new Utilities.DbUtility.DbAccess(strconn, Utilities.DbUtility.DbProviderType.SqlServer);

using (StockDBEntities db2 = new StockDBEntities())
{
     db2.Database.CommandTimeout = 200;//响应时间，以秒为单位，此处为200秒，可根据情况不写
     //因连接配置已经模板生成，此处获取连接字符串的方式就是：db2.Database.Connection.ConnectionString
     Utilities.DbUtility.DbAccess db = new Utilities.DbUtility.DbAccess(db2.Database.Connection.ConnectionString, Utilities.DbUtility.DbProviderType.SqlServer);
}