舍入平均 Linq 函数 C#

Question

我想对 Average Linq 函数的结果进行四舍五入，可以吗？

public IEnumerable<GetLocationsAverageDTO> GetLocationsAverageByCompanyId(int id)
{
    try
    {
        var baseQuery = _dbContext.Answers.AsNoTracking()
                                .Where(p => p.Location.Company.Id == id
                                            && p.Question.Type != QuestionType.Text)
                                .GroupBy(g => new { Location = g.Location.Name })
                                .Select(x =>
                                            new GetLocationsAverageDTO
                                            {
                                                LocationName = x.Key.Location,
                                                Average = x.Average(f => f.Numeric)
                                            })
                                .OrderBy(x => x.LocationName);

        var dto = baseQuery.ToList();

        return dto;
    }
    catch (Exception error)
    {
        _logger.Error("[Error in SurveyService.GetLocationsAverageByCompanyId - id: " + id + " - Error: " + error + "]");

        return null;
    }
}

就像是

Average = x.Average(f => f.Numeric, 2) // result: 45,21

Answer 1

您可以简单地应用Math.Round()函数，该函数接受第二个参数，该参数指示您想要的 Linq 查询末尾的小数位数。

Average = Math.Round(x.Average(f => f.Numeric), 2);

Answer 2

我真的不知道舍入是否在 SQL-Providers 中进行了翻译，但您可以进行内存中迭代并使用Math.Round()它在所有情况下都有效：

var dto = baseQuery.ToList();
foreach(var item in dto)
{
    item.Average = Math.Round(item.Average , 2);
}