如何在LinqToSql中执行WHERE ... IN ...子句? [英] How to do a WHERE...IN... clause in LinqToSql?

问题描述

忍受我，我开始了:如何使用WHERE ... IN ...类型的子句选择多个元素

Bear with me, I'm beginning: How can I select multiple elements using a WHERE...IN... type of clause as in

select * from orders where orderid in (1, 4, 5)

在LinqToSql中?我宁愿不要有lambda表情，因为它们会吓到我.预先感谢！

in LinqToSql? I'd prefer not to have a lambda expression since they scare me. Thanks in advance!

推荐答案

LINQ具有"Contains"，类似于"IN"，但是却以相反的方式表示-元素不在集合中，而集合包含" 一个元素.

LINQ has "Contains" which is like "IN" but expressed the other way round - an element isn't "in" a set, a set "contains" an element.

int[] validIds = { 1, 4, 5 };
var query = from order in db.Orders
            where validIds.Contains(order.Id)
            select order

这是用lambda更简单地表示(IMO):

This is more simply expressed (IMO) with a lambda though:

int[] validIds = { 1, 4, 5 };
var query = db.Orders.Where(order => validIds.Contains(order.Id));

我意识到lambda是新的"，因此在某种程度上令人恐惧，但是用双手抓住它们确实很值得.他们很可爱.

I realise lambdas are "new" and therefore scary to some extent, but it's really well worth grabbing hold of them with both hands. They're lovely.

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