Question

这个SQL语句与LINQ之间是否有直接的转换？

Select ProductId 
From ProductReport
Where ProductId NOT IN(Select ProductId From ClientProduct Where ClientId = CAST('06ae6be1-ca94-44c9-bd30-f1d4f3ac3264' AS uniqueidentifier))

我可以通过两个LINQ查询实现相同的功能，但我宁愿使用一个查询并点击数据库一次。

Answer 1

var q = from p in ProductReport
        where !ClientProduct.Any(c => 
           c.ClientId == new Guid("06ae6be1-ca94-44c9-bd30-f1d4f3ac3264") && 
           p.ProductId == c.ProductId)
        select p.ProductId;

Answer 2

假设您的模型中有导航 - and you should。

var clientId = new Guid("06ae6be1-ca94-44c9-bd30-f1d4f3ac3264");
var q = from pr in Context.ProductReports
        where !pr.Clients.Any(c => c.ClientId == clientId)
        select pr.ProductId;

LINQ to EF4中的“不在哪里”

2 个答案: