C#从sql获取月度报告

我已经完成了年度报告，现在我需要总结访客的月度统计数据。我使用的datetimerpicker只有月份和年份

我不知道如何获得月度报告，所以我只包含一些看起来与数据库中相同的字符串

SqlCommand cmd = new SqlCommand("SELECT ISNULL(SUM(Male),0) as Male,ISNULL(SUM(Female),0)  as Female ,ISNULL(SUM(Pax),0)  as Pax,ISNULL(SUM(Single),0)  as Single,ISNULL(SUM(Married),0)  as Married,ISNULL(SUM(Students),0)  as Students,ISNULL(SUM(Elementary),0)  as Elementary,ISNULL(SUM(Highschool),0)  as Highschool, ISNULL(SUM(College),0)  as College,ISNULL(SUM(PWD),0)  as PWD, ISNULL(SUM([AR Users]),0)  as ARUsers,ISNULL(SUM([12 Below]),0)  as age1,ISNULL(SUM([13-21]),0)  as age2,ISNULL(SUM([22-35]),0)  as age3,ISNULL(SUM([36-50]),0)  as age4,ISNULL(SUM([51-65]),0)  as age5,ISNULL(SUM([65 Above]),0)  as age6 FROM  [tbl_Registration] where [Date Added] >= '"
            + dtpMonth.Value.Month.ToString() + "/" + "01" + "/" + dtpMonth.Value.Year.ToString() + "' AND  [Date Added] <'" + dtpMonth.Value.AddMonths(1).Month.ToString() + "/" + "01" + "/" + dtpMonth.Value.Year.ToString() + "'  ;", connection);

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在使用SQL查询时，可以对日期范围使用BETWEEN运算符，如

WHERE date BETWEEN firstDate AND lastDate

要得到一个月的第一个和最后一个日期，你可以简单地这样做

var firstDayOfMonth = new DateTime(year, month, 1);
var lastDayOfMonth = firstDayOfMonth.AddMonths(1).AddDays(-1);

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您应该使用小于而不是大于。九月在十月之前，而不是之后。”2018年1月9日>=2018年1月10日代码正在运行，但也显示了其他年份的报告。ex.09/2018运行良好，但09/2017报告也显示了这一点。

var firstDayOfMonth = new DateTime(year, month, 1);
var lastDayOfMonth = firstDayOfMonth.AddMonths(1).AddDays(-1);