Specified type member not supported in LINQ to Entities

问题:

I have an enum type called StatusTypes

public enum StatusTypes {     Open = 1,     Allocated = 2,     WorkInProgress = 3,     WaitingOnRequestor = 4,     WaitingOnThirdParty = 5,     Monitoring = 6,     Testing = 7,     OnHold = 8,     Complete = 9,     SignedOff = 10,     Reopened = 11 } 

I'm trying to use this in my repository....

public IQueryable GetAllOutstandingIncidents() {     return from i in db.Incidents                where i.Status != Types.StatusTypes.SignedOff && i.Status != Types.StatusTypes.Complete && i.DeletedDateTime != null                orderby i.DueDateTime                select i;     } 

...and then use it in my view...

                                                                /   /                                                                                                      

... but I'm getting the error "The specified type member 'Status' is not supported in LINQ to Entities. Only initializers, entity members, and entity navigation properties are supported."

Any help gratefully received!

UPDATE TO SHOW incident.cs

public class Incident {     public int IncidentID { get; set; }     public DomainUser Caller { get; set; }      [Display(Name = "Caller Type")]     public Types.CallerTypes CallerType { get; set; }      public Service Service { get; set; }     public Category Category { get; set; }     public Subcategory Subcategory { get; set; }     public string Title { get; set; }      [Display(Name = "Problem Description")]     public string ProblemDescription { get; set; }      public Equipment Equipment { get; set; }      public Types.ImpactTypes Impact { get; set; }     public Types.UrgencyTypes Urgency { get; set; }      [Display(Name = "Priority")]     public Types.PriorityTypes Priority { get; set; }      [Display(Name="Estimated time for completion")]     public DateTime? DueDateTime { get; set; }      [Display(Name="Date/Time")]     public DateTime? CreatedDateTime { get; set; }     public DomainUser CreatedBy { get; set; }      [Display(Name = "Allocated To")]     public HelpDeskMember AllocatedTo { get; set; }     public DateTime? AllocatedDateTime { get; set; }      public DateTime? ClosedDateTime { get; set; }     public int? ClosedBy { get; set; }      public DateTime? ReopenedDateTime { get; set; }     public int? ReopenedBy { get; set; }      public DateTime? DeletedDateTime { get; set; }     public HelpDeskMember DeletedBy { get; set; }      public Decimal? EstimatedInternalCost { get; set; }     public Decimal? EstimatedResources { get; set; }     public Decimal? RealInternalCost { get; set; }     public Decimal? EstimatedExternalCost { get; set; }     public Decimal? RealExternalCost { get; set; }     public Decimal? EstimatedTotalCost { get; set; }     public Decimal? RealTotalCost { get; set; }      public string CostCode { get; set; }      public string TimeRequired { get; set; }     public string ActualTimeTaken { get; set; }      public Types.StatusTypes Status { get; set; }      public string Solution { get; set; }      public bool UserSignedOff { get; set; }      public bool OverdueEmailSent { get; set; }     public bool EscalatedEmailSent { get; set; }      public ICollection Notes { get; set; }     public ICollection Attachments { get; set; }     public ICollection History { get; set; }      public Incident()     {         Notes = new List();         Attachments = new List();         History = new List();     } } 

回答1:

As I've already said try to cast both part to the int type

public IQueryable GetAllOutstandingIncidents() {     return from i in db.Incidents         where (int)i.Status != (int)Types.StatusTypes.SignedOff             && (int)i.Status != (int)Types.StatusTypes.Complete             && i.DeletedDateTime != null         orderby i.DueDateTime         select i; } 

UPDATE

That's a feature of Code First. You should do following. Change your class so:

[Column("Status", TypeName = "int")] public int InternalStatus { get; set; } public StatusTypes Status { get; set; } 

And use following query:

context.Incidents.Where(i => i.InternalStatus == (int)StatusTypes.Allocated); 

I've found this info here

回答2:

You can also convert to LINQ To Object with .AsEnumerable():

public IQueryable GetAllOutstandingIncidents() {     return from i in db.Incidents.AsEnumerable()                where i.Status != Types.StatusTypes.SignedOff && i.Status != Types.StatusTypes.Complete && i.DeletedDateTime != null                orderby i.DueDateTime                select i; } 

Depending of what you want, it could be a not so good solution: Instead of just pulling one object from the database, it will pull all objects when you call .AsEnumerable().

回答3:

Try this instead

return from i in db.Incidents                where i.Status != (int)Types.StatusTypes.SignedOff && i.Status != (int)Types.StatusTypes.Complete && i.DeletedDateTime != null                orderby i.DueDateTime                select i; 

回答4:

In your Incident class:

private int statusId; public Types.StatusTypes Status  {      get      {         return (Types.StatusTypes)statusId;     }     set     {         statusId = (int)value;     } }  public Int StatusId  {      get      {         return statusId;     } } 

Then in you method:

public IQueryable GetAllOutstandingIncidents() {     int signedOffStatusType = (int)Types.StatusTypes.SignedOff;         int completeStatusType = (int)Types.StatusTypes.Complete;       return from i in db.Incidents            where i.StatusId != signedOffStatusType                && i.StatusId != completeStatusType                && i.DeletedDateTime != null         orderby i.DueDateTime         select i; } 

Or using method syntax:

public IQueryable GetAllOutstandingIncidents() {     int signedOffStatusType = (int)Types.StatusTypes.SignedOff;         int completeStatusType = (int)Types.StatusTypes.Complete;       return db.Incidents.Where(i => i.StatusId != signedOffStatusType                                  && i.StatusId != completeStatusType                                  && i.DeletedDateTime != null)                        .OrderBy(i => i.DueDateTime); } 

文章来源: Specified type member not supported in LINQ to Entities