[英]Linq Error on Left outer join
i have an alert table that has a 1:many mapping to devices. 我有一个警报表,其中有一个1:许多映射到设备的表。 This relationship is conveyed ina mapping table.
此关系在映射表中传达。 When I try to produce a left outer join from the mapping table to the various asset type tables i get the following error:System.Security.VerificationException: Operation could destabilize the runtime.
当我尝试从映射表到各种资产类型表生成左外部联接时,出现以下错误:System.Security.VerificationException:操作可能会使运行时不稳定。
var alertAssets = (from a in dc.MSAlert_Assets
from b in dc.MSRfids.Where(x => x.accountID == a.accountID && x.rfID == a.tagNum && x.custNum == a.custNum).DefaultIfEmpty()
from c in dc.MSDevices.Where(x => x.accountID == a.accountID && x.deviceID == a.deviceID).DefaultIfEmpty()
from d in dc.MSGroups.Where(x => x.accountID == a.accountID && x.groupID == a.groupID).DefaultIfEmpty()
let x = grrepo.getAssetsForGroupID(d.groupID, d.accountID)
where a.alertID == alertID
select new {... specific objects}
I thought it may be a narrowing issue, so i Enumarated the IQueryable, but still the same issue. 我认为这可能是一个缩小的问题,因此我对IQueryable进行了编号,但仍然是相同的问题。
The one thing that jumps out at me is the line 跳到我身上的一件事是线
let x = grrepo.getAssetsForGroupID(d.groupID, d.accountID)
If d can be null (since it's a left outer join because of the DefaultIfEmpty), then how can you access the d.groupID or the d.accountID. 如果d可以为null(由于DefaultIfEmpty而由于它是左外部联接),那么如何访问d.groupID或d.accountID。 I think that is where it is failing since it cannot get the properties/variables from null.
我认为那是失败的地方,因为它无法从null获得属性/变量。
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