如何在 EF 中按子属性排序

发布于 2024-10-31 01:45:01 字数 621 浏览 0 评论 0原文

我基本上想用 Lambda EF 来写这个。

select c.* from company c
left join companyfeature cf 
on c.companyID = cf.companyID
AND cf.FeatureID = 1
order by FeatureID desc, c.Name

我似乎无法弄清楚。
在 EF 中，它们是 Companies & CompanyFeatures 实体

对于 Claus： 我从来没有说过我没有尝试过，我只是说我无法弄清楚。但为了证明我不是你的免费装载者；这是我的 linq 语句。（是的，我已经准备好了 FK）

Companies
.OrderByDescending(c => c.CompanyFeatures.Any(f => f.FeatureID == 1))
.ThenBy(c => c.Name)

这确实有效，但它会产生一个不合时宜的 SQL 语句，它需要 6 秒，而上面的 SQL 语句则需要 1 毫秒。所以我认为我写错了。我知道有很多比我聪明的人，所以我希望有人愿意分享他们的知识。提前致谢。

原文

I basically want to write this in Lambda EF.

select c.* from company c
left join companyfeature cf 
on c.companyID = cf.companyID
AND cf.FeatureID = 1
order by FeatureID desc, c.Name

I can't seem to figure it out.
In EF they are Companies & CompanyFeatures entities

For Claus:
I never said I didn't try, I said I couldn't figure it out. But to prove I'm not some free loader to you; here is my linq statement. (Yes I have my FK in place)

Companies
.OrderByDescending(c => c.CompanyFeatures.Any(f => f.FeatureID == 1))
.ThenBy(c => c.Name)

That actually works, but it produces an ungodly SQL statement that takes 6 seconds vs ms for my SQL statement above. So I assume I've wrote it incorrectly. I know there are a lot smarter people out there than me so I'm hoping someone will be willing to share their knowledge. Thanks in advance.

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

深空失忆 2024-11-07 01:45:01

试试这个（请注意，这是 C#，但 VB 非常相似。）：

 var result = 
    from Company in Companies
    from CompanyFeature in Company.CompanyFeatures.Where(cf => cf.FeatureID == 1).DefaultIfEmpty()
    orderby Company.Name
    select { Company, CompanyFeature };

Try this (Note that this is C# but VB is quite similar.):

 var result = 
    from Company in Companies
    from CompanyFeature in Company.CompanyFeatures.Where(cf => cf.FeatureID == 1).DefaultIfEmpty()
    orderby Company.Name
    select { Company, CompanyFeature };

回复收藏 0 原文

~没有更多了~