Question

我目前有一个LINQ查询：

public List<EventSchool> GetEventSchools(int eventID)
    {
        var eventSchools = db.EventSchools
            .Include("Organisation")
            .Where(e => e.EventID == eventID)
            .ToList();

        foreach (var ev in eventSchools)
        {
            if (db.EventSchoolKeyStages.Where(e => e.EventSchoolID == ev.EventSchoolID).Count() > 0)
            {
                int ks = db.EventSchoolKeyStages
                .Where(e => ev.EventSchoolID == ev.EventSchoolID)
                .Sum(e => e.Males + e.Females);

                ev.StudentNumbers = ks;
            }
        }

        return eventSchools;
    }

当我检查EventSchools时，列表中所有项目的学生编号显示为第一项。

例如，如果列表中有3个项目：

Item 1 - Males = 10, Females = 10
Item 2 - Males = 1, Females = 2
Item 3 - Males = 200, Females = 500

所有项目的StudentNumbers为20，而不是：

Item 1 - 20
Item 2 - 3
Item 3 - 700

不确定我做错了什么？

Answer 1

您的查询中有错误：

.Where(e => ev.EventSchoolID == ev.EventSchoolID)

应该是：

。Where(e => e.EventSchoolID == ev.EventSchoolID)

Answer 2

你这里有一个错字：

.Where(e => ev.EventSchoolID == ev.EventSchoolID)

这个lambda永远是真的。我怀疑你的意思

.Where(e => e.EventSchoolID == ev.EventSchoolID)
            ^^^

在指定地点有所不同。

我的LINQ to Entities查询出了问题

2 个答案: