I have an existing index (IX_ItemImportSummaryId) which was generated from the ForeignKey on ItemImportSummary because that is the default index naming structure. If I try to then explicitly create an index with the same name on the Id field, it will drop the index and then create it again in the migration script.
The funny thing is, if I give it a non-default name instead, it will simply rename the index rather than drop then create it. It almost seems like EF is stupid in this scenario and doesn't realize that it can just not do anything at all.
public class ItemImportSummaryDetail
{
public int Id { get; set; }
[ForeignKey("ItemImportSummaryId")]
public virtual ItemImportSummary ItemImportSummary { get; set; }
[Index("IX_ItemImportSummaryId", IsUnique = false)]
[Index("IX_Mpbid", 2, IsUnique = true)]
public int ItemImportSummaryId { get; set; }
[Required]
[StringLength(maximumLength:10)]
[Index("IX_Mpbid", 1, IsUnique = true)]
public string Mpbid { get; set; }
}
This is what add-migration generates:
DropIndex("dbo.ItemImportSummaryDetails", new[] { "ItemImportSummaryId" });
CreateIndex("dbo.ItemImportSummaryDetails", "ItemImportSummaryId");
Related
I have an application, structured like this:
Application.Domain
Application.Web.Mvc
Application.MongoDb
In Application.Domain i keep all the POCOs of the application (the domain models).
public class Product
{
public string Id { get; set; }
public string ProductName { get; set; }
public DateTime CreatedDate { get; set; }
}
Now, because i am using MongoDb, i also need to use some of the [BsonAttribute], in order to customize the serialization process.
For example:
public class Product
{
[BsonId]
public string Id { get; set; }
public string ProductName { get; set; }
[BsonDateTimeOptions(Kind = DateTimeKind.Local, DateOnly = true)]
public DateTime CreatedDate { get; set; }
}
If i add these attributes, i will need to also add a reference to MongoDB.Bson.Serialization.Attributes in the Application.Domain project, which i want to avoid.
I think the correct way to do this is to create mapping objects in the Application.MongoDb project, and always map them from POCO to MongoObjects and the other way around every time i work with MongoDb repos.
If this is the correct solution, isn't this a bit overkill?
Is it possible to insert duplicate rows in Many to Many relationship? This is my class:
public class EventPaintballBundle
{
[Key, Column(Order = 0)]
public int EventID { get; set; }
[Key, Column(Order = 1)]
public int PaintballBundleID { get; set; }
public virtual Event Event { get; set; }
public virtual PaintballBundle PaintballBundle { get; set; }
[Range(1, Int32.MaxValue)]
public int PersonCount { get; set; }
[Required]
public DateTime Data { get; set; }
}
I want to insert second row of those values. The differences are on Date Date and PersonCount value
EventPaintballBundle xx = new EventPaintballBundle() { PaintballBundleID = 1, EventID = 155, Data = DateTime.Now, PersonCount = 5 };
dc.EventPaintballBundles.Add(xx);
dc.SaveChanges();
I'm getting error while I want to insert a duplicate of two keys.
{"Violation of PRIMARY KEY constraint 'PK_dbo.EventPaintballBundles'.
Cannot insert duplicate key in object 'dbo.EventPaintballBundles'. The
duplicate key value is (155, 1).\r\nThe statement has been
terminated."}
How to solve this problem?
Create a primary key that isn't the combination of :
public int EventID { get; set; }
public int PaintballBundleID { get; set; }
The new primary should be unique and not related to anything that actually exist, this key will exist only to make your model work database wise.
It's a classic mistake : to think your primary key should represent something that exist... NO
I learned it the hard way : even if i think that some combination of existing data will stay forever unique. I don't use it. I ALWAYS create my primary key from my own design, not representing anything real.
I am creating a junction table between Identity User and a Game table. This table is called UserGame and has two foreign keys (UserID, GameID) and one additional field to store the score.
public class UserGame
{
[Key]
public string ApplicationUserID { get; set; }
public virtual ApplicationUser ApplicationUser { get; set; }
public int GameID { get; set; }
public virtual Game Game { get; set; }
public int Score { get; set; }
}
My confusion lies with creating a new UserGame record. How would I go about doing this and is my approach correct?
Update (This worked):
[HttpPost]
public ActionResult SubmitScore(int gameID, int score)
{
var playerRecord = new UserGame();
playerRecord.ApplicationUserID = User.Identity.GetUserId();
playerRecord.GameID = gameID;
playerRecord.Score = score;
return Json(new { success = true });
}
Both ApplicationUserId and GameId must have a [Key, Column(Order = 0)] attribute. Just set the first to Order 0 and the other to 1.
public class UserGame
{
[Key, Column(Order = 0)]
public string ApplicationUserID { get; set; }
public virtual ApplicationUser ApplicationUser { get; set; }
[Key, Colum(Order = 1)]
public int GameID { get; set; }
public virtual Game Game { get; set; }
public int Score { get; set; }
}
Then you have the choice to add new record, go through nav property from Game or ApplicationUser or directly with your UserGame class.
Example of configuring many-to-many relationship in entity framework
Examle of inserting related objects
A couple of tips:
I wouldn't declare a primary key in the junction entity as junctions are usually defined by composite keys.
Keep in mind that dbcontext.SaveChanges() will look for child entities and save those as well.
I'm having a little of trouble with the following classes:
public class TwoVariableDetails
{
public TwoVariableDetails()
{
MovementsPerBlocks = new HashSet<MovementsRow>();
MovementsPerShiftTypes = new HashSet<MovementsRow>();
MovementsPerMachines = new HashSet<MovementsRow>();
MovementsPerShifts = new HashSet<MovementsRow>();
}
[Key]
public Guid TwoVariableDetailsId { get; set; }
[Required]
[MaxLength(50)]
public string Name { get; set; }
[Required]
[MaxLength(1000)]
[DataType(DataType.MultilineText)]
public string Description { get; set; }
public virtual ICollection<MovementsRow> MovementsPerBlocks { get; set; }
public virtual ICollection<MovementsRow> MovementsPerShiftTypes { get; set; }
public virtual ICollection<MovementsRow> MovementsPerMachines { get; set; }
public virtual ICollection<MovementsRow> MovementsPerShifts { get; set; }
}
[Table("Movement")]
public class MovementsRow
{
public MovementsRow()
{
MovementsCells = new HashSet<MovementsCell>();
}
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
[CsvField(Ignore = true)]
public Guid MovementId { get; set; }
[Required]
public int RowNo { get; set; }
[Required]
[CsvField(Ignore = true)]
public Guid ModelId { get; set; }
[ForeignKey("ModelId")]
[CsvField(Ignore = true)]
public virtual TwoVariableDetails Model { get; set; }
[TypeConverter(typeof(MovementsCellTypeConverter))]
public virtual ICollection<MovementsCell> MovementsCells { get; set; }
}
[Table("MovementCell")]
public class MovementsCell
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
[CsvField(Ignore = true)]
public Guid CellId { get; set; }
[Required]
public int ColumnNo { get; set; }
[Required]
public int Count { get; set; }
[Required]
[CsvField(Ignore = true)]
public Guid MovementId { get; set; }
[ForeignKey("MovementId")]
[CsvField(Ignore = true)]
public virtual MovementsRow Model { get; set; }
}
When I try to save it to the database I get the following error:
The INSERT statement conflicted with the FOREIGN KEY constraint "FK_dbo.Movement_dbo.TwoVariableDetails_ModelId". The conflict occurred in database "aspnet-GreenCranes.UI-20130516", table "dbo.TwoVariableDetails", column 'TwoVariableDetailsId'.
The statement has been terminated.
This is the code I'm using for saving:
twoVariableDetails.TwoVariableDetailsId = Guid.NewGuid();
_context.TwoVariableDetailsModels.Add(twoVariableDetails);
_context.SaveChanges();
My table looks like this:
Movement
- Column
- MovementId
- RowNo
- ModelId(FK, uniqueidentifier, not null)
- TwoVariableDetails_TwoVariableDetailsId(FK, uniqueidentifier, null)
- TwoVariableDetails_TwoVariableDetailsId2(FK, uniqueidentifier, null)
- TwoVariableDetails_TwoVariableDetailsId3(FK, uniqueidentifier, null)
- TwoVariableDetails_TwoVariableDetailsId4(FK, uniqueidentifier, null)
- Keys
- FK_dbo.Movement_dbo.TwoVariableDetails_ModelId
- FK_dbo.Movement_dbo.TwoVariableDetails_TwoVariableDetails_TwoVariableDetailsId
- FK_dbo.Movement_dbo.TwoVariableDetails_TwoVariableDetails_TwoVariableDetailsId1
- FK_dbo.Movement_dbo.TwoVariableDetails_TwoVariableDetails_TwoVariableDetailsId2
- FK_dbo.Movement_dbo.TwoVariableDetails_TwoVariableDetails_TwoVariableDetailsId3
I'm not sure what is the problem with my approach. Should I change the MovementsRow class to have four Model properties and four modelid fk and then use InverseProperty attribute?
MovementsRow.Model belongs to another relationship than the four collections in TwoVariableDetails. That's the reason why you don't have four, but five foreign keys in the database table. When you insert twoVariableDetails into the DB and it contains a MovementRow instance in one of the collections EF expects that its ModelId is set to a Guid that references an existing TwoVariableDetails row - which it doesn't apparently. Hence the exception.
Should I change the MovementsRow class to have four Model properties
and four modelid fk and then use InverseProperty attribute?
I'd say yes. It's probably the best solution. The alternative is to have no Model property at all in MovementRow. It's working but you would not be able to navigate from MovementRow to TwoVariableDetails then.
Your FK_dbo.Movement_dbo.TwoVariableDetails_ModelId is being violated, simply put - the ModelId that the Movement record is using doesn't yet exist in TwoVariableDetails.
If you wanted to keep it simple, and transactional, then you could use TransactionScope along with your database context, save the TwoVariableDetails first in the transaction, and then the records that relate back to it:
using (var context = new MyDbContext())
using (var tranScope = new TransactionScope(TransactionScopeOption.Required) {
// don't save the Movement records yet
twoVariableDetails.TwoVariableDetailsId = Guid.NewGuid();
_context.TwoVariableDetailsModels.Add(twoVariableDetails);
_context.SaveChanges();
// now create the movement records, add them to twoVariableDetails
...
_context.SaveChanges();
// commit the transaction
scope.Complete();
}
Used code first and everything appears to work apart from the below which also worked before when I used ObjectContext and called context.PCBuilds.AddObject(pcBuild) but after switching to DbContext it's giving me the error.
EFDbContext context = new EFDbContext();
public ActionResult Index()
{
PCBuild pcBuild = new PCBuild();
pcBuild.BuildID = 34245;
pcBuild.BuildName = "Test99";
pcBuild.MarkUp = 25;
pcBuild.BDetails = new List<BDetail>();
context.PCBuilds.Add(pcBuild);
//repository.PCBuilds.Attach(pcBuild);
context.SaveChanges();
return View();
}
Giving me the: Cannot insert the value NULL into column 'BuildID', table 'C:\USERS\ADMIN\DOCUMENTS\VISUAL STUDIO 2010\PROJECTS\NEOCART\NEOCART.WEBUI\APP_DATA\NEODBX.MDF.dbo.PCBuilds'; column does not allow nulls. INSERT fails. Where as BuildID was clearly set before the SaveChanges is called. Appears that calling the .Add(pcBuild) doesn't add the populated object for some reason and when savechanges is called it attempts to insert an empty PCBuild ?
Here are the POCO's
public class PCBuild
{
[Key]
public int BuildID { get; set; }
public string BuildName { get; set; }
public string Socket { get; set; }
public decimal? MarkUp {get; set;}
[InverseProperty("PCBuild")]
public virtual ICollection<BDetail> BDetails { get; set; }
}
public class BDetail
{
[Key]
public int LineID { get; set; }
[ForeignKey("PCBuild")]
public int BuildID { get; set; }
[ForeignKey("Product")]
public int ProductID { get; set; }
public bool? IsSelected { get; set; }
[InverseProperty("BDetails")]
public virtual PCBuild PCBuild { get; set; }
[InverseProperty("BDetails")]
public virtual Product Product { get; set; }
}
Use StoreGeneratedAttribute on the PCBuild.BuildID property. It is not only a key but IDENTITY field.
UPDATE
Actually, it should be [DatabaseGenerated(DatabaseGenerationOption.Identity)] annotation. The article linked above describes early CTP version.
UPDATE 2
Wait, the key is being generated by the app, it is not an identity column in database? Change annotation to [DatabaseGenerated(DatabaseGenerationOption.None)], re-create the context and rebuild the application.
I'm not really familiar with the Code First approach, but could it be that when you specify the BuildID as being a [Key] field, it is setting it as an auto identity field in the database?
As such it may be blocking your attempt to write to it.
Try removing the [Key] identifier, then recreate the database. Can you then save the object ok?