Redigera
Testet nedan gjordes med SQL Server och SqlClient som leverantör. Det faktum att problemet inte är reproducerbart med SQL Server väcker frågan om MySql leverantören du använder har en bugg som skapar felaktig SQL för din LINQ-fråga. Det ser ut som samma problem som i denna fråga
där problemet uppstod med en MySql leverantör också och kunde inte reproduceras med SqlClient /SQL-server.
Jag har testat exemplet i fetstil (med EF 4.3.1) och kan inte återskapa problemet:
using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
namespace EFInclude
{
public class Harbor
{
public int HarborId { get; set; }
public virtual ICollection<Ship> Ships { get; set; }
public string Description { get; set; }
}
public class Ship
{
public int ShipId { get; set; }
public int HarborId { get; set; }
public virtual Harbor Harbor { get; set; }
public virtual ICollection<CrewMember> CrewMembers { get; set; }
public string Description { get; set; }
}
public class CrewMember
{
public int CrewMemberId { get; set; }
public int ShipId { get; set; }
public virtual Ship Ship { get; set; }
public int RankId { get; set; }
public virtual Rank Rank { get; set; }
public int ClearanceId { get; set; }
public virtual Clearance Clearance { get; set; }
public string Description { get; set; }
}
public class Rank
{
public int RankId { get; set; }
public virtual ICollection<CrewMember> CrewMembers { get; set; }
public string Description { get; set; }
}
public class Clearance
{
public int ClearanceId { get; set; }
public virtual ICollection<CrewMember> CrewMembers { get; set; }
public string Description { get; set; }
}
public class MyContext : DbContext
{
public DbSet<Harbor> Harbors { get; set; }
public DbSet<Ship> Ships { get; set; }
public DbSet<CrewMember> CrewMembers { get; set; }
public DbSet<Rank> Ranks { get; set; }
public DbSet<Clearance> Clearances { get; set; }
}
class Program
{
static void Main(string[] args)
{
Database.SetInitializer(new DropCreateDatabaseAlways<MyContext>());
using (var context = new MyContext())
{
context.Database.Initialize(true);
var harbor = new Harbor
{
Ships = new HashSet<Ship>
{
new Ship
{
CrewMembers = new HashSet<CrewMember>
{
new CrewMember
{
Rank = new Rank { Description = "Rank A" },
Clearance = new Clearance { Description = "Clearance A" },
Description = "CrewMember A"
},
new CrewMember
{
Rank = new Rank { Description = "Rank B" },
Clearance = new Clearance { Description = "Clearance B" },
Description = "CrewMember B"
}
},
Description = "Ship AB"
},
new Ship
{
CrewMembers = new HashSet<CrewMember>
{
new CrewMember
{
Rank = new Rank { Description = "Rank C" },
Clearance = new Clearance { Description = "Clearance C" },
Description = "CrewMember C"
},
new CrewMember
{
Rank = new Rank { Description = "Rank D" },
Clearance = new Clearance { Description = "Clearance D" },
Description = "CrewMember D"
}
},
Description = "Ship CD"
}
},
Description = "Harbor ABCD"
};
context.Harbors.Add(harbor);
context.SaveChanges();
}
using (var context = new MyContext())
{
DbSet<Harbor> dbSet = context.Set<Harbor>();
IQueryable<Harbor> query = dbSet;
query = query.Include(entity => entity.Ships);
query = query.Include(entity => entity.Ships.Select(s => s.CrewMembers));
query = query.Include(entity => entity.Ships.Select(s => s.CrewMembers.Select(cm => cm.Rank)));
query = query.Include(entity => entity.Ships.Select(s => s.CrewMembers.Select(cm => cm.Clearance)));
var sqlString = query.ToString();
// see below for the generated SQL query
var harbor = query.Single();
Console.WriteLine("Harbor {0} Description = \"{1}\"",
harbor.HarborId, harbor.Description);
foreach (var ship in harbor.Ships)
{
Console.WriteLine("- Ship {0} Description = \"{1}\"",
ship.ShipId, ship.Description);
foreach (var crewMember in ship.CrewMembers)
{
Console.WriteLine("-- CrewMember {0} Description = \"{1}\"",
crewMember.CrewMemberId, crewMember.Description);
Console.WriteLine("-- CrewMember {0} Rank Description = \"{1}\"",
crewMember.CrewMemberId, crewMember.Rank.Description);
Console.WriteLine("-- CrewMember {0} Clearance Description = \"{1}\"",
crewMember.CrewMemberId, crewMember.Clearance.Description);
}
}
Console.ReadLine();
}
}
}
}
Utdata är:
Enligt din beskrivning i fet stil borde jag ha:CrewMember 1 Beskrivning ="Rank A" och samma röra för de andra 3 besättningsmedlemmarna. Men jag har inte det här.
Är något annorlunda i mitt testprogram jämfört med din kod där du har felet?
Redigera
Den genererade SQL-koden för frågan (se rad var sqlString = query.ToString(); i källkoden ovan är följande innehållet i sqlString ) är:
SELECT
[Project1].[HarborId] AS [HarborId],
[Project1].[Description] AS [Description],
[Project1].[C2] AS [C1],
[Project1].[ShipId] AS [ShipId],
[Project1].[HarborId1] AS [HarborId1],
[Project1].[Description1] AS [Description1],
[Project1].[C1] AS [C2],
[Project1].[CrewMemberId] AS [CrewMemberId],
[Project1].[ShipId1] AS [ShipId1],
[Project1].[RankId] AS [RankId],
[Project1].[ClearanceId] AS [ClearanceId],
[Project1].[Description2] AS [Description2],
[Project1].[RankId1] AS [RankId1],
[Project1].[Description3] AS [Description3],
[Project1].[ClearanceId1] AS [ClearanceId1],
[Project1].[Description4] AS [Description4]
FROM ( SELECT
[Extent1].[HarborId] AS [HarborId],
[Extent1].[Description] AS [Description],
[Join3].[ShipId1] AS [ShipId],
[Join3].[HarborId] AS [HarborId1],
[Join3].[Description1] AS [Description1],
[Join3].[CrewMemberId] AS [CrewMemberId],
[Join3].[ShipId2] AS [ShipId1],
[Join3].[RankId1] AS [RankId],
[Join3].[ClearanceId1] AS [ClearanceId],
[Join3].[Description2] AS [Description2],
[Join3].[RankId2] AS [RankId1],
[Join3].[Description3] AS [Description3],
[Join3].[ClearanceId2] AS [ClearanceId1],
[Join3].[Description4] AS [Description4],
CASE WHEN ([Join3].[ShipId1] IS NULL) THEN CAST(NULL AS int) WHEN ([Join3].[CrewMemberId] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C1],
CASE WHEN ([Join3].[ShipId1] IS NULL) THEN CAST(NULL AS int) ELSE 1 END AS [C2]
FROM [dbo].[Harbors] AS [Extent1]
LEFT OUTER JOIN (SELECT [Extent2].[ShipId] AS [ShipId1], [Extent2].[HarborId] AS [HarborId], [Extent2].[Description] AS [Description1], [Join2].[CrewMemberId], [Join2].[ShipId2], [Join2].[RankId1], [Join2].[ClearanceId1], [Join2].[Description2], [Join2].[RankId2], [Join2].[Description3], [Join2].[ClearanceId2], [Join2].[Description4]
FROM [dbo].[Ships] AS [Extent2]
LEFT OUTER JOIN (SELECT [Extent3].[CrewMemberId] AS [CrewMemberId], [Extent3].[ShipId] AS [ShipId2], [Extent3].[RankId] AS [RankId1], [Extent3].[ClearanceId] AS [ClearanceId1], [Extent3].[Description] AS [Description2], [Extent4].[RankId] AS [RankId2], [Extent4].[Description] AS [Description3], [Extent5].[ClearanceId] AS [ClearanceId2], [Extent5].[Description] AS [Description4]
FROM [dbo].[CrewMembers] AS [Extent3]
INNER JOIN [dbo].[Ranks] AS [Extent4] ON [Extent3].[RankId] = [Extent4].[RankId]
LEFT OUTER JOIN [dbo].[Clearances] AS [Extent5] ON [Extent3].[ClearanceId] = [Extent5].[ClearanceId] ) AS [Join2] ON [Extent2].[ShipId] = [Join2].[ShipId2] ) AS [Join3] ON [Extent1].[HarborId] = [Join3].[HarborId]
) AS [Project1]
ORDER BY [Project1].[HarborId] ASC, [Project1].[C2] ASC, [Project1].[ShipId] ASC, [Project1].[C1] ASC