EF6：多对多关系返回空集合

Question

I've been trying to figure this out for the past 3 hours, and I'm sure I'm missing something very obvious...

Here is the model code:

[Table("company")]
public partial class company
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public company()
    {
        job = new HashSet<job>();
        contact = new HashSet<contact>();
    }

    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int companyId { get; set; }

    [Required]
    [StringLength(255)]
    public string name { get; set; }

    [StringLength(255)]
    public string address { get; set; }

    [StringLength(255)]
    public string locality { get; set; }

    [StringLength(255)]
    public string city { get; set; }

    [StringLength(100)]
    public string state { get; set; }

    [StringLength(16)]
    public string postalCode { get; set; }

    [StringLength(2)]
    public string country { get; set; }

    [StringLength(16)]
    public string phone { get; set; }

    [StringLength(63)]
    public string email { get; set; }

    [StringLength(127)]
    public string website { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<job> job { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<contact> contact { get; set; }
}

[Table("contact")]
public partial class contact
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public contact()
    {
        this.company = new HashSet<company>();
    }
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int contactId { get; set; }

    [Required]
    [StringLength(64)]
    public string firstName { get; set; }

    [Required]
    [StringLength(64)]
    public string lastName { get; set; }

    [StringLength(1)]
    public string middleInitial { get; set; }

    public string title { get; set; }

    [StringLength(18)]
    public string phoneNumber { get; set; }

    [StringLength(128)]
    public string emailAddress { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<company> company { get; set; }
}

[Table("job")]
public class job
{
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2214:DoNotCallOverridableMethodsInConstructors")]
    public job()
    {
        company = new HashSet<company>();
    }

    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int jobId { get; set; }

    public string jobTitle { get; set; }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly")]
    public virtual ICollection<company> company { get; set; }

}

And in OnModelCreating I have this:

modelBuilder.Entity<company>()
    .HasMany(e => e.job)
    .WithMany(e => e.company)
    .Map(m => m.ToTable("company_job", "dbo").MapLeftKey("companyId").MapRightKey("jobId"));

modelBuilder.Entity<company>()
    .HasMany(e => e.contact)
    .WithMany(e => e.company)
    .Map(m => m.ToTable("company_contact", "dbo").MapLeftKey("companyId").MapRightKey("contactId"));

I've checked all of the following on the database end:

• All three main tables exist and match the model column-for-column.
• All foreign key relationships to the bridge tables exist.
• Both bridge tables have a composite primary key consisting of the two columns.
• Both bridge tables are named matching the Map method parameters, as do the columns in the bridge tables.
• The database has appropriate data that should cause job and contact entities to appear under all company entities.
• Manually written queries to the database do succeed in producing the expected data.

However:

ctx.company.Where(x => x.companyId == 300).job.Count()

always returns 0 . Trying:

ctx.company.Where(x => x.companyId == 300).job.FirstOrDefault()

returns null .

I tried setting up logging on the context:

Database.Log = msg => System.Diagnostics.Debug.WriteLine(msg);

And I noticed that the only queries ever sent to the database are for the company table. It doesn't do a join query. It never even touches the job or contact tables, or the bridge tables. It simply makes a single query to the company table with the correct WHERE clause but never goes further.

Just for kicks I tried reversing the order of the fields in the .Map call, but that had no effect. (in other words: .Map(m => m.ToTable("company_job", "dbo").MapLeftKey("jobId").MapRightKey("companyId")) didn't change things.)

Ok, what am I missing?

Answer 1

ACK...

In the context constructor was this:

base.Configuration.ProxyCreationEnabled = false;

I removed it and it seems to work now!

(I inherited this code, so the lesson here is: never assume that code you inherit does exactly what you think it'll do!)