实体框架6，无法添加新条目

Question

I'm using Entity framework 6.1.3 on a .Net 4.5 WCF/HTTP app. I'm having some trouble saving new data.

my code looks like this :

using (AgpModel model = new AgpModel())
{
    Entite.db.commentaire comment = commentaire.toDB();
    model.commentaires.Add(comment);
    model.SaveChanges();
    commentaire.Id = comment.id;
}

AgpModel is my context, commentaire is my front model wich can be serialized over WCF, and comment is the object i'm trying to save.

The toDB() is the method transforming commentaire into comment .

When adding my very first data to the table, I'm having an exception on the call of SaveChanges() which says :

Store update, insert, or delete statement affected an unexpected number of rows (0). Entities may have been modified or deleted since entities were loaded. See http://go.microsoft.com/fwlink/?LinkId=472540 for information on understanding and handling optimistic concurrency exceptions.

I tried the method available at the link below only to have this exception :

OriginalValues cannot be used for entities in the Added state.

Reading on the table works fine.

Here is some extra code that can help you understand :

The toDB method :

public db.commentaire toDB()
{
    return new db.commentaire() {
        id = this.Id,
        stagiaire = this.IdStagiaire,
        utilisateur = this.IdUtilisateur,
        niveau = (int)this.Niveau,
        contenu = this.Contenu,
        date = this.Date
    };
}

The commentaire class :

[Table("agp.commentaires")]
public partial class commentaire
{
    [Key]
    [Column("commentaire", Order = 0)]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int id { get; set; }

    [Key]
    [Column(Order = 1)]
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int utilisateur { get; set; }

    [Key]
    [Column("date", Order = 2, TypeName = "smalldatetime")]
    public DateTime date { get; set; }

    [Key]
    [Column(Order = 3)]
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int stagiaire { get; set; }

    [Key]
    [Column(Order = 4)]
    [StringLength(300)]
    public string contenu { get; set; }

    [Key]
    [Column(Order = 5)]
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public int niveau { get; set; }

    public virtual utilisateur utilisateur1 { get; set; }

    public virtual Stagiaire Stagiaire1 { get; set; }
}

Edit :

The request passed to sql server 2008 :

INSERT [agp].[commentaires]([utilisateur], [date], [stagiaire], [contenu], [niveau]) VALUES (@0, @1, @2, @3, @4)
SELECT [commentaire] FROM [agp].[commentaires] WHERE @@ROWCOUNT > 0 AND [commentaire] = scope_identity() AND [utilisateur] = @0 AND [date] = @1 AND [stagiaire] = @2 AND [contenu] = @3 AND [niveau] = @4

with those parameters :

• @0: '1' (Type = Int32)
• @1: '30/07/2015 18:50:02' (Type = DateTime2)
• @2: '1786' (Type = Int32)
• @3: 'coucou' (Type = AnsiString, Size = 300)
• @4: '2' (Type = Int32)

Executed on my own this way and waorks ok :

DECLARE @0 as INT  = 1;
DECLARE @1 AS DateTime2 = '30/07/2015 18:50:02';
DECLARE @2 AS int = 1786;
DECLARE @3 AS nvarchar(300) = 'coucou';
DECLARE @4 AS int = 2;

INSERT [agp].[commentaires]([utilisateur], [date], [stagiaire], [contenu], [niveau])
VALUES (@0, @1, @2, @3, @4)
SELECT [commentaire]
FROM [agp].[commentaires]
WHERE @@ROWCOUNT > 0 AND [commentaire] = scope_identity() AND [utilisateur] = @0 AND [date] = @1 AND [stagiaire] = @2 AND [contenu] = @3 AND [niveau] = @4

Still don't understand

Answer 1

With your public DateTime date { get; set; } public DateTime date { get; set; } public DateTime date { get; set; } set to Column(Typename="smalldatetime") and your database appearing to expect a european date object. Perhaps passing a generic DateTime to SQL is giving a smalldatetime that is out of bounds for the expected minimum/maximum allowable DateTime values.

I would suggest setting CultureInfo enGB = new CultureInfo("en-GB"); for your session as it appears your database may be specifying a specific date format. I would assume that Entity Framework would put the format in the format accepted in all cases:

YYYYMMDD
YYYY-MM-DDThh:nn:ss[.mmmmmmm]

However, your exception is not pointing to an exact column causing the issue. Your composite keys are all declared properly, and your toDB() call appears to have populated all of the columns with data (though you'd need to set a breakpoint and validate that yourself). The only other thing I can think of that would trigger that error is an acceptable DateTime being set in your model, but being converted into an SQL format that is out-of-bounds of the min/max range for smalldatetime due to culture difference.