Question

我正在尝试解决问题：

我不知道如何从我的查询中访问cnt值，或者如何重写它以便在我的项目中使用

Select * from samples as s INNER JOIN (SELECT sampleId, SUM(quantity) cnt FROM locationsamples GROUP BY sampleID) sl ON sl.sampleID=s.SampleId;

上面的查询为我提供了所需的信息。

如何从我的控制器访问Summed cnt值，以便我可以在视图中阅读它？

public class samples
{
[Key]
    public int SampleId { get; set; }

    //many to many relationship for locations (one sample can be in many locations, with a quantity in each)
    public virtual ICollection<locationsamples> locationsamples { get; set; 
 }

public class locationsamples
{
    public int locationsamplesID { get; set; }

    public int locationID { get; set; }
    public virtual location location { get; set; }

    public int sampleID { get; set; }
    public virtual sample sample { get; set; }

    public int quantity { get; set; }

}

Answer 1

您可以在locationamples上分组，然后选择您需要的聚合字段。你想要的是这样的：

var list = dbContext.locationsamples
    .GroupBy(e => e.sampleID)
    .Select(group => new
    {
        SampleId = group.key,
        Cnt = group.Sum(c => c.quantity),
    }).ToList();

将子表中的int值与ASP MVC中的父索引列表相加

1 个答案: