将不确定变为确定~DateTime.MinValue和MaxValue引发的异常

回到目录

问题描述：

SqlDateTime 溢出。必须介于 1/1/1753 12:00:00 AM 和 12/31/9999 11:59:59 PM 之间

概念相关

.Net中的DateTime结构类中的MinValue和MaxValue有时会引发一个异常，那就是日期溢出的问题，您输入的日期必须介于 1753 年 1 月 1 日到 9999 年 12 月 31 日之间，而DateTime.MinValue实际上不是1753 年 1 月 1日，而是0000年１月１日，而数据库可以接收的日期时间最小值为1753/1/1，这时由于.net产生的DateTime.MinValue远远小于它，所以，它出现了日期溢出的问题。

解决问题

我们作一个测试：

 　 Console.Write(DateTime.MinValue);
    Console.Write(DateTime.MaxValue);

它的结果为：

aaarticlea/png;base64,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" alt="" />

所以，如果你在程序中，进行数据库查询时，需要对日期进行查询，如果希望给日期变量一个默认值，那不会使用DateTime.MinValue，而要使用ＳＱＬ的数据结果中的MinValue，它位于System.Data.SqlTypes名称空间下，表示与ＳＱＬＳＥＲＶＥＲ对应的数据类型，测试代码如下：

 Console.WriteLine(System.Data.SqlTypes.SqlDateTime.MinValue);
 Console.WriteLine(System.Data.SqlTypes.SqlDateTime.MaxValue);

它的结果为：

aaarticlea/png;base64,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" alt="" />

它在程序中的体现为：

　　　　　/// 用户列表
        /// </summary>
        /// <param name="username"></param>
        /// <param name="deptname"></param>
        /// <param name="page"></param>
        /// <returns></returns>
        public ActionResult Index(
            string username,
            string deptname,
            DateTime? startTime,
            DateTime? endTime,
            int? page)
        {

            UserManager userManager = new UserManager();
            ViewData["SiteMapID"] = ;

            var specification = new UserSpecification(startTime, endTime, username, deptname);
            var model = userManager.GetWebManageUsers(specification, new PageParameters(page ?? , base.PageSize));
            model.AddParameters = new System.Collections.Specialized.NameValueCollection();
            model.AddParameters.Add("username", username);
            model.AddParameters.Add("deptname", deptname);
            model.AddParameters.Add("startTime", (startTime).ToString());
            model.AddParameters.Add("endTime", (endTime).ToString());

            if (Request.IsAjaxRequest())
                return PartialView("List", model);
            return View(model);
        }

在上面的代码中，我们的DateTime类型，由于与数据库查询相关，所以，可以使用SqlDateTime类型代替！

回到目录