Some stupid situation about PK in C#: MVC3 can't insert a new record with passed PK and try to insert NULL as Primary key
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Good day. I have MSSQL2008 database. And I made a proper model for one of the existing table (VLANs). 

public DbSet<VLAN> VLANs { get; set; }

VLAN Model has field:

[Key][Required]
public int VLAN_ID { get; set; } //in the "VLAN" table it is PK
...

Then I try to insert a new value

_db.VLANs.Add(VLANToEdit); //<-- Here VLANToEdit has VLANToEdit.VLAN_ID == 144. No such data in the table
_db.SaveChanges(); //<--Here I got an exception. 

MSSQL can't insert a NULL value into VLAN_ID field. But why? I pass a real value but null? What s wrong? I got Message	"Cannot insert the value NULL into column 'VLAN_ID', table 'VMMExt.dbo.VLANs'; column does not allow nulls. INSERT fails.\r\nThe statement has been terminated."	string


If i remove [Key] attribute I got an error in other places about missing key fields in VLANs tables.




How to fix this and force to insert with provided primary key value?



