子頂部1和多於等於使用Linq的子查詢

Question

我的SQL查詢如下。

select st.kProductVersionPlatformFrom, st.kProductVersionPlatformTo, pv.kProduct, pv.nId, * 
from vSysTable st 
left join vProductVersion pv on st.kProductVersionPlatformFrom = pv.nId 
where 
st.kProductVersionPlatformTo >= (select top 1 nid from vProductVersion where kProduct = 2 
           and kProductVersionPlatform = 87 order by nId desc) 

我試圖將其轉換爲LINQ的，但無法找到的方式來使用大於等於

var systemTableList = (from sysTableEntity in _sysTableEntityRepository.AsQueryable() 
         join versionEntity in _productVersionRepository.AsQueryable() on 
          sysTableEntity.ProductVersionPlatformFrom equals versionEntity.Id 
          into leftjoined 
          from joinedsysVersionTable in leftjoined.DefaultIfEmpty() 
          where (from versionEntity in _productVersionRepository.AsQueryable() 
            where versionEntity.ProductEntityId.Equals(2) && 
           versionEntity.PlatformProductVersionEntityId.Equals(87) 
            orderby versionEntity.Id descending 
            select versionEntity.Id).Take(1).Contains(sysTableEntity.ProductVersionPlatformFrom >= 87) 
         select new { sysTableEntity}); 

但它給我的錯誤附近的包含關鍵字的「之類的說法無法推斷用法「

這裏用什麼來代替包含？我也嘗試使用但仍然無法使用。

Answer 1

因爲子查詢

select top 1 nid 
from vProductVersion 
where kProduct = 2 
and kProductVersionPlatform = 87 
order by nId desc 

不相關，您可以單獨使用它，然後將其值用在你的主查詢。另外，你確定，查詢總是會返回值（非空）？

var nid = from versionEntity in _productVersionRepository.AsQueryable() 
where versionEntity.ProductEntityId.Equals(2) && 
versionEntity.PlatformProductVersionEntityId.Equals(87) 
orderby versionEntity.Id descending 
select versionEntity.Id).First(); 

然後用這個：

var systemTableList = 
    from sysTableEntity in _sysTableEntityRepository.AsQueryable() 
     join versionEntity in _productVersionRepository.AsQueryable() 
    on sysTableEntity.ProductVersionPlatformFrom equals versionEntity.Id 
      into leftjoined 
    from joinedsysVersionTable in leftjoined.DefaultIfEmpty() 
    where ProductVersionPlatformTo >= nid;