我有这种搜索方法:
public List<Employeees> AutoSuggestemployeee(string keyword,long employeeeTypeId,int count) { return context.Employeees.Where( x => x.EmployeeeName.Contains(keyword) && x.EmployeeeTypeId == employeeeTypeId) .Take(count).ToList(); }
我有另一个Employeees集合,比如“BadEmployeees”,我想要的是使用相同的先前方法返回除“BadEmployeees”之外的所有Employeees.
我试着像这样写:
return context.Employeees.Where( x => x.EmployeeeName.Contains(keyword) && x.EmployeeeTypeId == employeeeTypeId) .Except(BadEmployeees).Take(count).ToList();
但它提供了一个例外,即Except可以使用Int,Guid等数据类型……
解决方法
如果您很乐意检索所有数据然后执行“除外”,则相对容易:
return context.Employees .Where(x => x.EmployeeName.Contains(keyword) && x.EmployeeTypeId == employeeeTypeId) // Limit the data *somewhat* .Take(count + BadEmployees.Count) // Do the rest of the query in-process .AsEnumerable() .Except(BadEmployees) .Take(count) .ToList();
或者:
// I'm making some assumptions about property names here... var badEmployeeIds = badEmployees.Select(x => x.EmployeeId) .ToList(); return context.Employees .Where(x => x.EmployeeName.Contains(keyword) && x.EmployeeTypeId == employeeeTypeId) && !badEmployeeIds.Contains(x.EmployeeId)) .Take(count) .ToList();