SQL Query使用不存在和连接的LINQ语法
我的SQL查询就像下面在SQL中工作正常我需要将其转换为LINQ语法
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语法我试过了
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();
出错：
操作员'！' 不能应用于'int'类型的操作数
任何线索我犯了错误？
你可以尝试这样的：
(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();
要么
(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();
尝试这个：
(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();
我认为你原来的查询很好，你只需要在where子句中添加另一对括号：
(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).Any())
select lk).ToList();