Question

尝试查询两个日期之间的结果，获取列值，然后将其求和成小数。不幸的是，每次我传递不同的日期时，我都会得到所有结果。在两个日期之间获取结果有些问题。任何帮助表示赞赏。

这就是我现在拥有的：

 private static decimal QuerySales(DateTime startDateTime, DateTime endDateTime, IQueryable<ProductsSummary> summaries)
    {
        var relevantSummaries = (from summary in summaries
                     where ((summary.Date >= startDateTime.Date) && (summary.Date <= endDateTime.Date))
                     select summary);

        var netSales = (from records in relevantSummaries
                      select summaries.Sum(x => x.NetSales)).ToList();

        decimal sales = netSales.Any() ? netSales[0] : 0;
        return sales;
    }

Answer 1

这是解决方案：

 private static decimal QuerySales(DateTime startDateTime, DateTime endDateTime, IQueryable<ProductsSummary> summaries)
    {
        decimal sales = 0;
        var relevantSummaries = (from summary in summaries
                     where ((summary.Date >= startDateTime.Date) 
                            && (summary.Date <= endDateTime.Date))
                     select summary.NetSales);

        if (relevantSummaries != null)
        {
           sales = relevantSummaries.Sum();
        }

        return sales;
    }

Answer 2

更简单，对LINQ使用Method Syntax：

  return summaries
   .Where(s => s.Date >= startDateTime.Date && s.Date <= endDateTime.Date)
   .Sum(s => s.NetSales)

LINQ查询结果以获取两个日期之间的十进制总和

2 个答案: