使用不存在，并加入SQL查询来LINQ语法 [英] SQL Query to LINQ syntax using not exist and join

问题描述

我的SQL查询类似下面的工作在SQL
罚款，我需要将其转换为LINQ语法

My SQL query is like below working fine in SQL I need to convert this to LINQ syntax

SQL -

SELECT [Key], Id
FROM LocalizationKeys AS lk
WHERE NOT EXISTS (SELECT 1
                  FROM Languages AS l
                  JOIN LocalizationValues AS lv ON l.Id = lv.LanguageId
                  WHERE l.Title = 'en-US' AND lv.LocalizationKeyId = lk.Id)

LINQ语法我试过

var result = 

(from lk in localizationKey    
where !(from l in lang
        join lv in localizationValue on l.Id equals lv.LanguageId
        where l.Title == "en-US" && lv.LocalizationKeyId == lk.Id select 1).FirstOrDefault()   

 select lk).ToList();

获取错误：

运算符'！'不能应用于类型为INT

Operator '!' cannot be applied to operand of type 'int'

任何线索在哪里出错了？

Any clue where I made mistake?

推荐答案

您可以尝试这样的：

(from lk in localizationKey    
where (from l in lang
        join lv in localizationValue on l.Id equals lv.LanguageId
        where (l.Title == "en-US" && lv.LocalizationKeyId == lk.Id)   
       select l).FirstOrDefault() == null
 select lk).ToList();

或

(from lk in localizationKey    
where !(from l in lang
        join lv in localizationValue on l.Id equals lv.LanguageId
        where !(l.Title == "en-US" && lv.LocalizationKeyId == lk.Id) 
        select l).FirstOrDefault().Any()
 select lk).ToList();

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