我在LINQPad中测试了以下查询,它运行正常,但VS2010不喜欢它.
var topJobs = from j in streetlightDBEntities.Job
let mjobid = from m in streetlightDBEntities.Job.Include("Streetlight")
where m.Streetlight.StreetlightId == j.Streetlight.StreetlightId
orderby m.DateCompleted descending
select m.JobId
where mjobid.Take(5).Contains(j.JobId)
select j.JobId;
var notTopJobs = streetlightDBEntities.Job.Where(c => !topJobs.Contains(c.JobId));
我收到以下错误：
LINQ to Entities does not recognize the method ‘Boolean Contains[String](System.Linq.IQueryable`1[System.String],System.String)’ method,and this method cannot be translated into a store expression.
解决方法
使用
Queryable.Any
<TSource>.
而不是这个：
var notTopJobs = streetlightDBEntities
.Job
.Where(c => !topJobs.Contains(c.JobId));
做这个：
var notTopJobs = streetlightDBEntities
.Job
.Where(c => !topJobs.Any(x => x.JobId == c.JobId))
对原始查询执行相同操作.