Related
I've been wrestling with this for a while and can't quite figure out what's happening. I have a Card entity which contains Sides (usually 2) - and both Cards and Sides have a Stage. I'm using EF Codefirst migrations and the migrations are failing with this error:
Introducing FOREIGN KEY constraint 'FK_dbo.Sides_dbo.Cards_CardId' on
table 'Sides' may cause cycles or multiple cascade paths. Specify ON
DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY
constraints.
Here's my Card entity:
public class Card
{
public Card()
{
Sides = new Collection<Side>();
Stage = Stage.ONE;
}
[Key]
[Required]
public virtual int CardId { get; set; }
[Required]
public virtual Stage Stage { get; set; }
[Required]
[ForeignKey("CardId")]
public virtual ICollection<Side> Sides { get; set; }
}
Here's my Side entity:
public class Side
{
public Side()
{
Stage = Stage.ONE;
}
[Key]
[Required]
public virtual int SideId { get; set; }
[Required]
public virtual Stage Stage { get; set; }
[Required]
public int CardId { get; set; }
[ForeignKey("CardId")]
public virtual Card Card { get; set; }
}
And here's my Stage entity:
public class Stage
{
// Zero
public static readonly Stage ONE = new Stage(new TimeSpan(0, 0, 0), "ONE");
// Ten seconds
public static readonly Stage TWO = new Stage(new TimeSpan(0, 0, 10), "TWO");
public static IEnumerable<Stage> Values
{
get
{
yield return ONE;
yield return TWO;
}
}
public int StageId { get; set; }
private readonly TimeSpan span;
public string Title { get; set; }
Stage(TimeSpan span, string title)
{
this.span = span;
this.Title = title;
}
public TimeSpan Span { get { return span; } }
}
What's odd is that if I add the following to my Stage class:
public int? SideId { get; set; }
[ForeignKey("SideId")]
public virtual Side Side { get; set; }
The migration runs successfully. If I open up SSMS and look at the tables, I can see that Stage_StageId has been added to Cards (as expected/desired), however Sides contains no reference to Stage (not expected).
If I then add
[Required]
[ForeignKey("StageId")]
public virtual Stage Stage { get; set; }
public int StageId { get; set; }
To my Side class, I see StageId column added to my Side table.
This is working, but now throughout my application, any reference to Stage contains a SideId, which is in some cases totally irrelevant. I'd like to just give my Card and Side entities a Stage property based on the above Stage class without polluting the stage class with reference properties if possible... what am I doing wrong?
Because Stage is required, all one-to-many relationships where Stage is involved will have cascading delete enabled by default. It means, if you delete a Stage entity
the delete will cascade directly to Side
the delete will cascade directly to Card and because Card and Side have a required one-to-many relationship with cascading delete enabled by default again it will then cascade from Card to Side
So, you have two cascading delete paths from Stage to Side - which causes the exception.
You must either make the Stage optional in at least one of the entities (i.e. remove the [Required] attribute from the Stage properties) or disable cascading delete with Fluent API (not possible with data annotations):
modelBuilder.Entity<Card>()
.HasRequired(c => c.Stage)
.WithMany()
.WillCascadeOnDelete(false);
modelBuilder.Entity<Side>()
.HasRequired(s => s.Stage)
.WithMany()
.WillCascadeOnDelete(false);
I had a table that had a circular relationship with others and I was getting the same error. Turns out it is about the foreign key which was not nullable. If the key is not nullable the related object must be deleted, and circular relations don't allow that. So use nullable foreign key.
[ForeignKey("StageId")]
public virtual Stage Stage { get; set; }
public int? StageId { get; set; }
Anybody wondering how to do it in EF core:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
foreach (var relationship in modelBuilder.Model.GetEntityTypes().SelectMany(e => e.GetForeignKeys()))
{
relationship.DeleteBehavior = DeleteBehavior.Restrict;
}
..... rest of the code.....
I was getting this error for lots of entities when I was migrating down from an EF7 model to an EF6 version. I didn't want to have to go through each entity one at a time, so I used:
builder.Conventions.Remove<ManyToManyCascadeDeleteConvention>();
builder.Conventions.Remove<OneToManyCascadeDeleteConvention>();
You can set cascadeDelete to false or true (in your migration Up() method). Depends upon your requirement.
AddForeignKey("dbo.Stories", "StatusId", "dbo.Status", "StatusID", cascadeDelete: false);
In .NET Core I changed the onDelete option to ReferencialAction.NoAction
constraints: table =>
{
table.PrimaryKey("PK_Schedule", x => x.Id);
table.ForeignKey(
name: "FK_Schedule_Teams_HomeId",
column: x => x.HomeId,
principalTable: "Teams",
principalColumn: "Id",
onDelete: ReferentialAction.NoAction);
table.ForeignKey(
name: "FK_Schedule_Teams_VisitorId",
column: x => x.VisitorId,
principalTable: "Teams",
principalColumn: "Id",
onDelete: ReferentialAction.NoAction);
});
I had this issue also, I solved it instantly with this answer from a similar thread
In my case, I didn't want to delete the dependent record on key deletion. If this is the case in your situation just simply change the Boolean value in the migration to false:
AddForeignKey("dbo.Stories", "StatusId", "dbo.Status", "StatusID", cascadeDelete: false);
Chances are, if you are creating relationships which throw this compiler error but DO want to maintain cascade delete; you have an issue with your relationships.
I fixed this. When you add the migration, in the Up() method there will be a line like this:
.ForeignKey("dbo.Members", t => t.MemberId, cascadeDelete:True)
If you just delete the cascadeDelete from the end it will work.
Just for documentation purpose, to someone that comes on the future, this thing can be solved as simple as this, and with this method, you could do a method that disabled one time, and you could access your method normally
Add this method to the context database class:
protected override void OnModelCreating(DbModelBuilder modelBuilder) {
modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();
}
In .NET Core I played with all upper answers - but without any success.
I made changes a lot in DB structure and every time added new migration attempting to update-database, but received the same error.
Then I started to remove-migration one by one until Package Manager Console threw me exception:
The migration '20170827183131_***' has already been applied to the database
After that, I added new migration (add-migration) and update-database successfully
So my suggestion would be: clear out all your temp migrations, until your current DB state.
public partial class recommended_books : DbMigration
{
public override void Up()
{
CreateTable(
"dbo.RecommendedBook",
c => new
{
RecommendedBookID = c.Int(nullable: false, identity: true),
CourseID = c.Int(nullable: false),
DepartmentID = c.Int(nullable: false),
Title = c.String(),
Author = c.String(),
PublicationDate = c.DateTime(nullable: false),
})
.PrimaryKey(t => t.RecommendedBookID)
.ForeignKey("dbo.Course", t => t.CourseID, cascadeDelete: false) // was true on migration
.ForeignKey("dbo.Department", t => t.DepartmentID, cascadeDelete: false) // was true on migration
.Index(t => t.CourseID)
.Index(t => t.DepartmentID);
}
public override void Down()
{
DropForeignKey("dbo.RecommendedBook", "DepartmentID", "dbo.Department");
DropForeignKey("dbo.RecommendedBook", "CourseID", "dbo.Course");
DropIndex("dbo.RecommendedBook", new[] { "DepartmentID" });
DropIndex("dbo.RecommendedBook", new[] { "CourseID" });
DropTable("dbo.RecommendedBook");
}
}
When your migration fails you are given a couple of options:
'Introducing FOREIGN KEY constraint 'FK_dbo.RecommendedBook_dbo.Department_DepartmentID' on table 'RecommendedBook' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.
Could not create constraint or index. See previous errors.'
Here is an example of using the 'modify other FOREIGN KEY constraints' by setting 'cascadeDelete' to false in the migration file and then run 'update-database'.
Make your Foreign key attributes nullable. That will work.
This sounds weird and I don't know why, but in my case that was happening because my ConnectionString was using "." in "data source" attribute. Once I changed it to "localhost" it workded like a charm. No other change was needed.
The existing answers are great I just wanted to add that I ran into this error because of a different reason. I wanted to create an Initial EF migration on an existing DB but I didn't use the -IgnoreChanges flag and applied the Update-Database command on an empty Database (also on the existing fails).
Instead I had to run this command when the current db structure is the current one:
Add-Migration Initial -IgnoreChanges
There is likely a real problem in the db structure but save the world one step at a time...
In .NET 5 < and .NET Core 2.0 < you can use .OnDelete(DeleteBehavior.Restrict) in OnModelCreating like #Nexus23 answer but you do not need to disable cascade for every model.
Example with join entity type configuration many-to-many:
internal class MyContext : DbContext
{
public MyContext(DbContextOptions<MyContext> options)
: base(options)
{
}
public DbSet<Post> Posts { get; set; }
public DbSet<Tag> Tags { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Post>()
.HasMany(p => p.Tags)
.WithMany(p => p.Posts)
.UsingEntity<PostTag>(
j => j
.HasOne(pt => pt.Tag)
.WithMany(t => t.PostTags)
.HasForeignKey(pt => pt.TagId)
.OnDelete(DeleteBehavior.Restrict),
j => j
.HasOne(pt => pt.Post)
.WithMany(p => p.PostTags)
.HasForeignKey(pt => pt.PostId)
.OnDelete(DeleteBehavior.Restrict),
j =>
{
j.Property(pt => pt.PublicationDate).HasDefaultValueSql("CURRENT_TIMESTAMP");
j.HasKey(t => new { t.PostId, t.TagId });
});
}
}
public class Post
{
public int PostId { get; set; }
public string Title { get; set; }
public string Content { get; set; }
public ICollection<Tag> Tags { get; set; }
public List<PostTag> PostTags { get; set; }
}
public class Tag
{
public string TagId { get; set; }
public ICollection<Post> Posts { get; set; }
public List<PostTag> PostTags { get; set; }
}
public class PostTag
{
public DateTime PublicationDate { get; set; }
public int PostId { get; set; }
public Post Post { get; set; }
public string TagId { get; set; }
public Tag Tag { get; set; }
}
Sources:
https://learn.microsoft.com/en-us/ef/core/modeling/relationships?tabs=fluent-api%2Cfluent-api-simple-key%2Csimple-key#join-entity-type-configuration
https://learn.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.deletebehavior?view=efcore-5.0
This does require you to remove the many to many relationship yourself or you will receive the following error when you remove a parent entity:
The association between entity types '' and '' has been severed, but
the relationship is either marked as required or is implicitly
required because the foreign key is not nullable. If the
dependent/child entity should be deleted when a required relationship
is severed, configure the relationship to use cascade deletes.
Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to
see the key values
You can solve this by using DeleteBehavior.ClientCascade instead which will allow EF to perform cascade deletes on loaded entities.
internal class MyContext : DbContext
{
public MyContext(DbContextOptions<MyContext> options)
: base(options)
{
}
public DbSet<Post> Posts { get; set; }
public DbSet<Tag> Tags { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Post>()
.HasMany(p => p.Tags)
.WithMany(p => p.Posts)
.UsingEntity<PostTag>(
j => j
.HasOne(pt => pt.Tag)
.WithMany(t => t.PostTags)
.HasForeignKey(pt => pt.TagId)
.OnDelete(DeleteBehavior.Cascade),
j => j
.HasOne(pt => pt.Post)
.WithMany(p => p.PostTags)
.HasForeignKey(pt => pt.PostId)
.OnDelete(DeleteBehavior.ClientCascade),
j =>
{
j.Property(pt => pt.PublicationDate).HasDefaultValueSql("CURRENT_TIMESTAMP");
j.HasKey(t => new { t.PostId, t.TagId });
});
}
}
public class Post
{
public int PostId { get; set; }
public string Title { get; set; }
public string Content { get; set; }
public ICollection<Tag> Tags { get; set; }
public List<PostTag> PostTags { get; set; }
}
public class Tag
{
public string TagId { get; set; }
public ICollection<Post> Posts { get; set; }
public List<PostTag> PostTags { get; set; }
}
public class PostTag
{
public DateTime PublicationDate { get; set; }
public int PostId { get; set; }
public Post Post { get; set; }
public string TagId { get; set; }
public Tag Tag { get; set; }
}
https://learn.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.deletebehavior?view=efcore-5.0
None of the aforementioned solutions worked for me. What I had to do was use a nullable int (int?) on the foreign key that was not required (or not a not null column key) and then delete some of my migrations.
Start by deleting the migrations, then try the nullable int.
Problem was both a modification and model design. No code change was necessary.
The simple way is to, Edit your migration file (cascadeDelete: true) into (cascadeDelete: false) then after assign the Update-Database command in your Package Manager Console.if it's problem with your last migration then all right. Otherwise check your earlier migration history, copy those things, paste into your last migration file, after that do it the same thing. it perfectly works for me.
You could add this in your DataContext.cs, this works for me...
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();
modelBuilder.Conventions.Remove<ManyToManyCascadeDeleteConvention>();
}
I ran into the same problem and stuck for a long. The following steps saved me.
Go through the constraints and change the onDelete ReferentialAction to NoAction from Cascade
constraints: table =>
{
table.PrimaryKey("PK_table1", x => x.Id);
table.ForeignKey(
name: "FK_table1_table2_table2Id",
column: x => x.table2Id,
principalTable: "table2",
principalColumn: "Id",
onDelete: ReferentialAction.NoAction);
});
I've been wrestling with this for a while and can't quite figure out what's happening. I have a Card entity which contains Sides (usually 2) - and both Cards and Sides have a Stage. I'm using EF Codefirst migrations and the migrations are failing with this error:
Introducing FOREIGN KEY constraint 'FK_dbo.Sides_dbo.Cards_CardId' on
table 'Sides' may cause cycles or multiple cascade paths. Specify ON
DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY
constraints.
Here's my Card entity:
public class Card
{
public Card()
{
Sides = new Collection<Side>();
Stage = Stage.ONE;
}
[Key]
[Required]
public virtual int CardId { get; set; }
[Required]
public virtual Stage Stage { get; set; }
[Required]
[ForeignKey("CardId")]
public virtual ICollection<Side> Sides { get; set; }
}
Here's my Side entity:
public class Side
{
public Side()
{
Stage = Stage.ONE;
}
[Key]
[Required]
public virtual int SideId { get; set; }
[Required]
public virtual Stage Stage { get; set; }
[Required]
public int CardId { get; set; }
[ForeignKey("CardId")]
public virtual Card Card { get; set; }
}
And here's my Stage entity:
public class Stage
{
// Zero
public static readonly Stage ONE = new Stage(new TimeSpan(0, 0, 0), "ONE");
// Ten seconds
public static readonly Stage TWO = new Stage(new TimeSpan(0, 0, 10), "TWO");
public static IEnumerable<Stage> Values
{
get
{
yield return ONE;
yield return TWO;
}
}
public int StageId { get; set; }
private readonly TimeSpan span;
public string Title { get; set; }
Stage(TimeSpan span, string title)
{
this.span = span;
this.Title = title;
}
public TimeSpan Span { get { return span; } }
}
What's odd is that if I add the following to my Stage class:
public int? SideId { get; set; }
[ForeignKey("SideId")]
public virtual Side Side { get; set; }
The migration runs successfully. If I open up SSMS and look at the tables, I can see that Stage_StageId has been added to Cards (as expected/desired), however Sides contains no reference to Stage (not expected).
If I then add
[Required]
[ForeignKey("StageId")]
public virtual Stage Stage { get; set; }
public int StageId { get; set; }
To my Side class, I see StageId column added to my Side table.
This is working, but now throughout my application, any reference to Stage contains a SideId, which is in some cases totally irrelevant. I'd like to just give my Card and Side entities a Stage property based on the above Stage class without polluting the stage class with reference properties if possible... what am I doing wrong?
Because Stage is required, all one-to-many relationships where Stage is involved will have cascading delete enabled by default. It means, if you delete a Stage entity
the delete will cascade directly to Side
the delete will cascade directly to Card and because Card and Side have a required one-to-many relationship with cascading delete enabled by default again it will then cascade from Card to Side
So, you have two cascading delete paths from Stage to Side - which causes the exception.
You must either make the Stage optional in at least one of the entities (i.e. remove the [Required] attribute from the Stage properties) or disable cascading delete with Fluent API (not possible with data annotations):
modelBuilder.Entity<Card>()
.HasRequired(c => c.Stage)
.WithMany()
.WillCascadeOnDelete(false);
modelBuilder.Entity<Side>()
.HasRequired(s => s.Stage)
.WithMany()
.WillCascadeOnDelete(false);
I had a table that had a circular relationship with others and I was getting the same error. Turns out it is about the foreign key which was not nullable. If the key is not nullable the related object must be deleted, and circular relations don't allow that. So use nullable foreign key.
[ForeignKey("StageId")]
public virtual Stage Stage { get; set; }
public int? StageId { get; set; }
Anybody wondering how to do it in EF core:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
foreach (var relationship in modelBuilder.Model.GetEntityTypes().SelectMany(e => e.GetForeignKeys()))
{
relationship.DeleteBehavior = DeleteBehavior.Restrict;
}
..... rest of the code.....
I was getting this error for lots of entities when I was migrating down from an EF7 model to an EF6 version. I didn't want to have to go through each entity one at a time, so I used:
builder.Conventions.Remove<ManyToManyCascadeDeleteConvention>();
builder.Conventions.Remove<OneToManyCascadeDeleteConvention>();
You can set cascadeDelete to false or true (in your migration Up() method). Depends upon your requirement.
AddForeignKey("dbo.Stories", "StatusId", "dbo.Status", "StatusID", cascadeDelete: false);
In .NET Core I changed the onDelete option to ReferencialAction.NoAction
constraints: table =>
{
table.PrimaryKey("PK_Schedule", x => x.Id);
table.ForeignKey(
name: "FK_Schedule_Teams_HomeId",
column: x => x.HomeId,
principalTable: "Teams",
principalColumn: "Id",
onDelete: ReferentialAction.NoAction);
table.ForeignKey(
name: "FK_Schedule_Teams_VisitorId",
column: x => x.VisitorId,
principalTable: "Teams",
principalColumn: "Id",
onDelete: ReferentialAction.NoAction);
});
I had this issue also, I solved it instantly with this answer from a similar thread
In my case, I didn't want to delete the dependent record on key deletion. If this is the case in your situation just simply change the Boolean value in the migration to false:
AddForeignKey("dbo.Stories", "StatusId", "dbo.Status", "StatusID", cascadeDelete: false);
Chances are, if you are creating relationships which throw this compiler error but DO want to maintain cascade delete; you have an issue with your relationships.
I fixed this. When you add the migration, in the Up() method there will be a line like this:
.ForeignKey("dbo.Members", t => t.MemberId, cascadeDelete:True)
If you just delete the cascadeDelete from the end it will work.
Just for documentation purpose, to someone that comes on the future, this thing can be solved as simple as this, and with this method, you could do a method that disabled one time, and you could access your method normally
Add this method to the context database class:
protected override void OnModelCreating(DbModelBuilder modelBuilder) {
modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();
}
In .NET Core I played with all upper answers - but without any success.
I made changes a lot in DB structure and every time added new migration attempting to update-database, but received the same error.
Then I started to remove-migration one by one until Package Manager Console threw me exception:
The migration '20170827183131_***' has already been applied to the database
After that, I added new migration (add-migration) and update-database successfully
So my suggestion would be: clear out all your temp migrations, until your current DB state.
public partial class recommended_books : DbMigration
{
public override void Up()
{
CreateTable(
"dbo.RecommendedBook",
c => new
{
RecommendedBookID = c.Int(nullable: false, identity: true),
CourseID = c.Int(nullable: false),
DepartmentID = c.Int(nullable: false),
Title = c.String(),
Author = c.String(),
PublicationDate = c.DateTime(nullable: false),
})
.PrimaryKey(t => t.RecommendedBookID)
.ForeignKey("dbo.Course", t => t.CourseID, cascadeDelete: false) // was true on migration
.ForeignKey("dbo.Department", t => t.DepartmentID, cascadeDelete: false) // was true on migration
.Index(t => t.CourseID)
.Index(t => t.DepartmentID);
}
public override void Down()
{
DropForeignKey("dbo.RecommendedBook", "DepartmentID", "dbo.Department");
DropForeignKey("dbo.RecommendedBook", "CourseID", "dbo.Course");
DropIndex("dbo.RecommendedBook", new[] { "DepartmentID" });
DropIndex("dbo.RecommendedBook", new[] { "CourseID" });
DropTable("dbo.RecommendedBook");
}
}
When your migration fails you are given a couple of options:
'Introducing FOREIGN KEY constraint 'FK_dbo.RecommendedBook_dbo.Department_DepartmentID' on table 'RecommendedBook' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.
Could not create constraint or index. See previous errors.'
Here is an example of using the 'modify other FOREIGN KEY constraints' by setting 'cascadeDelete' to false in the migration file and then run 'update-database'.
Make your Foreign key attributes nullable. That will work.
This sounds weird and I don't know why, but in my case that was happening because my ConnectionString was using "." in "data source" attribute. Once I changed it to "localhost" it workded like a charm. No other change was needed.
The existing answers are great I just wanted to add that I ran into this error because of a different reason. I wanted to create an Initial EF migration on an existing DB but I didn't use the -IgnoreChanges flag and applied the Update-Database command on an empty Database (also on the existing fails).
Instead I had to run this command when the current db structure is the current one:
Add-Migration Initial -IgnoreChanges
There is likely a real problem in the db structure but save the world one step at a time...
In .NET 5 < and .NET Core 2.0 < you can use .OnDelete(DeleteBehavior.Restrict) in OnModelCreating like #Nexus23 answer but you do not need to disable cascade for every model.
Example with join entity type configuration many-to-many:
internal class MyContext : DbContext
{
public MyContext(DbContextOptions<MyContext> options)
: base(options)
{
}
public DbSet<Post> Posts { get; set; }
public DbSet<Tag> Tags { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Post>()
.HasMany(p => p.Tags)
.WithMany(p => p.Posts)
.UsingEntity<PostTag>(
j => j
.HasOne(pt => pt.Tag)
.WithMany(t => t.PostTags)
.HasForeignKey(pt => pt.TagId)
.OnDelete(DeleteBehavior.Restrict),
j => j
.HasOne(pt => pt.Post)
.WithMany(p => p.PostTags)
.HasForeignKey(pt => pt.PostId)
.OnDelete(DeleteBehavior.Restrict),
j =>
{
j.Property(pt => pt.PublicationDate).HasDefaultValueSql("CURRENT_TIMESTAMP");
j.HasKey(t => new { t.PostId, t.TagId });
});
}
}
public class Post
{
public int PostId { get; set; }
public string Title { get; set; }
public string Content { get; set; }
public ICollection<Tag> Tags { get; set; }
public List<PostTag> PostTags { get; set; }
}
public class Tag
{
public string TagId { get; set; }
public ICollection<Post> Posts { get; set; }
public List<PostTag> PostTags { get; set; }
}
public class PostTag
{
public DateTime PublicationDate { get; set; }
public int PostId { get; set; }
public Post Post { get; set; }
public string TagId { get; set; }
public Tag Tag { get; set; }
}
Sources:
https://learn.microsoft.com/en-us/ef/core/modeling/relationships?tabs=fluent-api%2Cfluent-api-simple-key%2Csimple-key#join-entity-type-configuration
https://learn.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.deletebehavior?view=efcore-5.0
This does require you to remove the many to many relationship yourself or you will receive the following error when you remove a parent entity:
The association between entity types '' and '' has been severed, but
the relationship is either marked as required or is implicitly
required because the foreign key is not nullable. If the
dependent/child entity should be deleted when a required relationship
is severed, configure the relationship to use cascade deletes.
Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to
see the key values
You can solve this by using DeleteBehavior.ClientCascade instead which will allow EF to perform cascade deletes on loaded entities.
internal class MyContext : DbContext
{
public MyContext(DbContextOptions<MyContext> options)
: base(options)
{
}
public DbSet<Post> Posts { get; set; }
public DbSet<Tag> Tags { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Post>()
.HasMany(p => p.Tags)
.WithMany(p => p.Posts)
.UsingEntity<PostTag>(
j => j
.HasOne(pt => pt.Tag)
.WithMany(t => t.PostTags)
.HasForeignKey(pt => pt.TagId)
.OnDelete(DeleteBehavior.Cascade),
j => j
.HasOne(pt => pt.Post)
.WithMany(p => p.PostTags)
.HasForeignKey(pt => pt.PostId)
.OnDelete(DeleteBehavior.ClientCascade),
j =>
{
j.Property(pt => pt.PublicationDate).HasDefaultValueSql("CURRENT_TIMESTAMP");
j.HasKey(t => new { t.PostId, t.TagId });
});
}
}
public class Post
{
public int PostId { get; set; }
public string Title { get; set; }
public string Content { get; set; }
public ICollection<Tag> Tags { get; set; }
public List<PostTag> PostTags { get; set; }
}
public class Tag
{
public string TagId { get; set; }
public ICollection<Post> Posts { get; set; }
public List<PostTag> PostTags { get; set; }
}
public class PostTag
{
public DateTime PublicationDate { get; set; }
public int PostId { get; set; }
public Post Post { get; set; }
public string TagId { get; set; }
public Tag Tag { get; set; }
}
https://learn.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.deletebehavior?view=efcore-5.0
None of the aforementioned solutions worked for me. What I had to do was use a nullable int (int?) on the foreign key that was not required (or not a not null column key) and then delete some of my migrations.
Start by deleting the migrations, then try the nullable int.
Problem was both a modification and model design. No code change was necessary.
The simple way is to, Edit your migration file (cascadeDelete: true) into (cascadeDelete: false) then after assign the Update-Database command in your Package Manager Console.if it's problem with your last migration then all right. Otherwise check your earlier migration history, copy those things, paste into your last migration file, after that do it the same thing. it perfectly works for me.
You could add this in your DataContext.cs, this works for me...
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();
modelBuilder.Conventions.Remove<ManyToManyCascadeDeleteConvention>();
}
I ran into the same problem and stuck for a long. The following steps saved me.
Go through the constraints and change the onDelete ReferentialAction to NoAction from Cascade
constraints: table =>
{
table.PrimaryKey("PK_table1", x => x.Id);
table.ForeignKey(
name: "FK_table1_table2_table2Id",
column: x => x.table2Id,
principalTable: "table2",
principalColumn: "Id",
onDelete: ReferentialAction.NoAction);
});
am working on some legacy code , would to add new table to the DB
and it would have two one to zero or one relation ship and I need "for some reason" The ForeignKeys in the new table to be defined as properties and The code :
public class EconomyInfo : Entity
{
/*other props*/
[ForeignKey("LogoImage")]
[Required]
public int LogoImage_Id { get; set; }
public virtual Image LogoImage { get; set; }
[ForeignKey("Organization")]
[Required]
public int Organization_Id { get; set; }
public virtual Organization Organization { get; set; }
}
public class Image : Entity
{
/*other props*/
public virtual EconomyInfo Economyinfo { get; set; }
}
public class Organization : Entity
{
/*other props*/
public virtual EconomyInfo EconomyInfo { get; set; }
}
public class Entity
{
public int Id { get; set; }
}
Like This EF don't generate migration and give the error
EconomyInfo_LogoImage_Source: : Multiplicity is not valid in Role 'EconomyInfo_LogoImage_Source' in relationship 'EconomyInfo_LogoImage'. Because the Dependent Role properties are not the key properties, the upper bound of the multiplicity of the Dependent Role must be '*'.
and the same for the other navigation property
and if i add those to lines in the the context class:
modelBuilder.Entity<Organization>().HasOptional(o => o.EconomyInfo).WithOptionalPrincipal();
modelBuilder.Entity<Image>().HasOptional(i => i.Economyinfo).WithOptionalPrincipal();
the migration will be generated without errors but it will be strange like :
public override void Up()
{
CreateTable(
"dbo.EconomyInfoes",
c => new
{
Id = c.Int(nullable: false, identity: true),
LogoImage_Id = c.Int(nullable: false),
Organization_Id = c.Int(nullable: false),
Image_Id = c.Int(),
Organization_Id1 = c.Int(),
})
.PrimaryKey(t => t.Id)
.ForeignKey("dbo.Images", t => t.LogoImage_Id, cascadeDelete: true)
.ForeignKey("dbo.Organizations", t => t.Organization_Id)
.ForeignKey("dbo.Images", t => t.Image_Id)
.ForeignKey("dbo.Organizations", t => t.Organization_Id1)
.Index(t => t.LogoImage_Id)
.Index(t => t.Organization_Id)
.Index(t => t.Image_Id)
.Index(t => t.Organization_Id1);
}
i know that i could edit the generated EF migration code to make it specify my needs , but there is no point of wasting hours dealing with EF and then give up and work around it , plus it won't be so practical to work with it later by my colleagues ,thanks in advance
I've just given up and decided to go with the work around as write my own migration for my new entity and tell the context to ignore it from the upcoming generated migration.
So my solution is this:
In the context class :
// Regarding unPossible configuration to make pre defined property as foreign key in one to zero or one relationship
// we wrote our migration and tell the context to ignore our model and its navigation property from other model classes
modelBuilder.Entity<Organization>().Ignore(o => o.EconomyInfo);
modelBuilder.Entity<Image>().Ignore(i => i.Economyinfo);
modelBuilder.Ignore<EconomyInfo>();
Organization class :
public virtual EconomyInfo EconomyInfo { get; set; }
Image class :
public virtual EconomyInfo Economyinfo { get; set; }
Manual written migration :
using System;
using System.Data.Entity.Migrations;
public partial class EconomyInfo : DbMigration
{
public override void Up()
{
CreateTable(
"dbo.EconomyInfoes",
c => new
{
Id = c.Int(nullable: false, identity: true),
LogoImage_Id = c.Int(nullable: false),
Organization_Id = c.Int(nullable: false),
})
.PrimaryKey(t => t.Id)
.ForeignKey("dbo.Images", t => t.LogoImage_Id)
.ForeignKey("dbo.Organizations", t => t.Organization_Id)
.Index(t => t.LogoImage_Id)
.Index(t => t.Organization_Id);
}
public override void Down()
{
DropForeignKey("dbo.EconomyInfoes", "Organization_Id", "dbo.Organizations");
DropForeignKey("dbo.EconomyInfoes", "LogoImage_Id", "dbo.Images");
DropIndex("dbo.EconomyInfoes", new[] { "Organization_Id" });
DropIndex("dbo.EconomyInfoes", new[] { "LogoImage_Id" });
DropTable("dbo.EconomyInfoes");
}
}
You may refer to this question also for more info How do I specify the foreign key in a one-to-one/zero relationship?
Note: I applied my written migration to database works fine, try to generate new migration, also works as expected, but not tested working with my new model class from code yet. Hopefully nothing will be messed later,
I've been wrestling with this for a while and can't quite figure out what's happening. I have a Card entity which contains Sides (usually 2) - and both Cards and Sides have a Stage. I'm using EF Codefirst migrations and the migrations are failing with this error:
Introducing FOREIGN KEY constraint 'FK_dbo.Sides_dbo.Cards_CardId' on
table 'Sides' may cause cycles or multiple cascade paths. Specify ON
DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY
constraints.
Here's my Card entity:
public class Card
{
public Card()
{
Sides = new Collection<Side>();
Stage = Stage.ONE;
}
[Key]
[Required]
public virtual int CardId { get; set; }
[Required]
public virtual Stage Stage { get; set; }
[Required]
[ForeignKey("CardId")]
public virtual ICollection<Side> Sides { get; set; }
}
Here's my Side entity:
public class Side
{
public Side()
{
Stage = Stage.ONE;
}
[Key]
[Required]
public virtual int SideId { get; set; }
[Required]
public virtual Stage Stage { get; set; }
[Required]
public int CardId { get; set; }
[ForeignKey("CardId")]
public virtual Card Card { get; set; }
}
And here's my Stage entity:
public class Stage
{
// Zero
public static readonly Stage ONE = new Stage(new TimeSpan(0, 0, 0), "ONE");
// Ten seconds
public static readonly Stage TWO = new Stage(new TimeSpan(0, 0, 10), "TWO");
public static IEnumerable<Stage> Values
{
get
{
yield return ONE;
yield return TWO;
}
}
public int StageId { get; set; }
private readonly TimeSpan span;
public string Title { get; set; }
Stage(TimeSpan span, string title)
{
this.span = span;
this.Title = title;
}
public TimeSpan Span { get { return span; } }
}
What's odd is that if I add the following to my Stage class:
public int? SideId { get; set; }
[ForeignKey("SideId")]
public virtual Side Side { get; set; }
The migration runs successfully. If I open up SSMS and look at the tables, I can see that Stage_StageId has been added to Cards (as expected/desired), however Sides contains no reference to Stage (not expected).
If I then add
[Required]
[ForeignKey("StageId")]
public virtual Stage Stage { get; set; }
public int StageId { get; set; }
To my Side class, I see StageId column added to my Side table.
This is working, but now throughout my application, any reference to Stage contains a SideId, which is in some cases totally irrelevant. I'd like to just give my Card and Side entities a Stage property based on the above Stage class without polluting the stage class with reference properties if possible... what am I doing wrong?
Because Stage is required, all one-to-many relationships where Stage is involved will have cascading delete enabled by default. It means, if you delete a Stage entity
the delete will cascade directly to Side
the delete will cascade directly to Card and because Card and Side have a required one-to-many relationship with cascading delete enabled by default again it will then cascade from Card to Side
So, you have two cascading delete paths from Stage to Side - which causes the exception.
You must either make the Stage optional in at least one of the entities (i.e. remove the [Required] attribute from the Stage properties) or disable cascading delete with Fluent API (not possible with data annotations):
modelBuilder.Entity<Card>()
.HasRequired(c => c.Stage)
.WithMany()
.WillCascadeOnDelete(false);
modelBuilder.Entity<Side>()
.HasRequired(s => s.Stage)
.WithMany()
.WillCascadeOnDelete(false);
I had a table that had a circular relationship with others and I was getting the same error. Turns out it is about the foreign key which was not nullable. If the key is not nullable the related object must be deleted, and circular relations don't allow that. So use nullable foreign key.
[ForeignKey("StageId")]
public virtual Stage Stage { get; set; }
public int? StageId { get; set; }
Anybody wondering how to do it in EF core:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
foreach (var relationship in modelBuilder.Model.GetEntityTypes().SelectMany(e => e.GetForeignKeys()))
{
relationship.DeleteBehavior = DeleteBehavior.Restrict;
}
..... rest of the code.....
I was getting this error for lots of entities when I was migrating down from an EF7 model to an EF6 version. I didn't want to have to go through each entity one at a time, so I used:
builder.Conventions.Remove<ManyToManyCascadeDeleteConvention>();
builder.Conventions.Remove<OneToManyCascadeDeleteConvention>();
You can set cascadeDelete to false or true (in your migration Up() method). Depends upon your requirement.
AddForeignKey("dbo.Stories", "StatusId", "dbo.Status", "StatusID", cascadeDelete: false);
In .NET Core I changed the onDelete option to ReferencialAction.NoAction
constraints: table =>
{
table.PrimaryKey("PK_Schedule", x => x.Id);
table.ForeignKey(
name: "FK_Schedule_Teams_HomeId",
column: x => x.HomeId,
principalTable: "Teams",
principalColumn: "Id",
onDelete: ReferentialAction.NoAction);
table.ForeignKey(
name: "FK_Schedule_Teams_VisitorId",
column: x => x.VisitorId,
principalTable: "Teams",
principalColumn: "Id",
onDelete: ReferentialAction.NoAction);
});
I had this issue also, I solved it instantly with this answer from a similar thread
In my case, I didn't want to delete the dependent record on key deletion. If this is the case in your situation just simply change the Boolean value in the migration to false:
AddForeignKey("dbo.Stories", "StatusId", "dbo.Status", "StatusID", cascadeDelete: false);
Chances are, if you are creating relationships which throw this compiler error but DO want to maintain cascade delete; you have an issue with your relationships.
I fixed this. When you add the migration, in the Up() method there will be a line like this:
.ForeignKey("dbo.Members", t => t.MemberId, cascadeDelete:True)
If you just delete the cascadeDelete from the end it will work.
Just for documentation purpose, to someone that comes on the future, this thing can be solved as simple as this, and with this method, you could do a method that disabled one time, and you could access your method normally
Add this method to the context database class:
protected override void OnModelCreating(DbModelBuilder modelBuilder) {
modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();
}
In .NET Core I played with all upper answers - but without any success.
I made changes a lot in DB structure and every time added new migration attempting to update-database, but received the same error.
Then I started to remove-migration one by one until Package Manager Console threw me exception:
The migration '20170827183131_***' has already been applied to the database
After that, I added new migration (add-migration) and update-database successfully
So my suggestion would be: clear out all your temp migrations, until your current DB state.
public partial class recommended_books : DbMigration
{
public override void Up()
{
CreateTable(
"dbo.RecommendedBook",
c => new
{
RecommendedBookID = c.Int(nullable: false, identity: true),
CourseID = c.Int(nullable: false),
DepartmentID = c.Int(nullable: false),
Title = c.String(),
Author = c.String(),
PublicationDate = c.DateTime(nullable: false),
})
.PrimaryKey(t => t.RecommendedBookID)
.ForeignKey("dbo.Course", t => t.CourseID, cascadeDelete: false) // was true on migration
.ForeignKey("dbo.Department", t => t.DepartmentID, cascadeDelete: false) // was true on migration
.Index(t => t.CourseID)
.Index(t => t.DepartmentID);
}
public override void Down()
{
DropForeignKey("dbo.RecommendedBook", "DepartmentID", "dbo.Department");
DropForeignKey("dbo.RecommendedBook", "CourseID", "dbo.Course");
DropIndex("dbo.RecommendedBook", new[] { "DepartmentID" });
DropIndex("dbo.RecommendedBook", new[] { "CourseID" });
DropTable("dbo.RecommendedBook");
}
}
When your migration fails you are given a couple of options:
'Introducing FOREIGN KEY constraint 'FK_dbo.RecommendedBook_dbo.Department_DepartmentID' on table 'RecommendedBook' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.
Could not create constraint or index. See previous errors.'
Here is an example of using the 'modify other FOREIGN KEY constraints' by setting 'cascadeDelete' to false in the migration file and then run 'update-database'.
Make your Foreign key attributes nullable. That will work.
This sounds weird and I don't know why, but in my case that was happening because my ConnectionString was using "." in "data source" attribute. Once I changed it to "localhost" it workded like a charm. No other change was needed.
The existing answers are great I just wanted to add that I ran into this error because of a different reason. I wanted to create an Initial EF migration on an existing DB but I didn't use the -IgnoreChanges flag and applied the Update-Database command on an empty Database (also on the existing fails).
Instead I had to run this command when the current db structure is the current one:
Add-Migration Initial -IgnoreChanges
There is likely a real problem in the db structure but save the world one step at a time...
In .NET 5 < and .NET Core 2.0 < you can use .OnDelete(DeleteBehavior.Restrict) in OnModelCreating like #Nexus23 answer but you do not need to disable cascade for every model.
Example with join entity type configuration many-to-many:
internal class MyContext : DbContext
{
public MyContext(DbContextOptions<MyContext> options)
: base(options)
{
}
public DbSet<Post> Posts { get; set; }
public DbSet<Tag> Tags { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Post>()
.HasMany(p => p.Tags)
.WithMany(p => p.Posts)
.UsingEntity<PostTag>(
j => j
.HasOne(pt => pt.Tag)
.WithMany(t => t.PostTags)
.HasForeignKey(pt => pt.TagId)
.OnDelete(DeleteBehavior.Restrict),
j => j
.HasOne(pt => pt.Post)
.WithMany(p => p.PostTags)
.HasForeignKey(pt => pt.PostId)
.OnDelete(DeleteBehavior.Restrict),
j =>
{
j.Property(pt => pt.PublicationDate).HasDefaultValueSql("CURRENT_TIMESTAMP");
j.HasKey(t => new { t.PostId, t.TagId });
});
}
}
public class Post
{
public int PostId { get; set; }
public string Title { get; set; }
public string Content { get; set; }
public ICollection<Tag> Tags { get; set; }
public List<PostTag> PostTags { get; set; }
}
public class Tag
{
public string TagId { get; set; }
public ICollection<Post> Posts { get; set; }
public List<PostTag> PostTags { get; set; }
}
public class PostTag
{
public DateTime PublicationDate { get; set; }
public int PostId { get; set; }
public Post Post { get; set; }
public string TagId { get; set; }
public Tag Tag { get; set; }
}
Sources:
https://learn.microsoft.com/en-us/ef/core/modeling/relationships?tabs=fluent-api%2Cfluent-api-simple-key%2Csimple-key#join-entity-type-configuration
https://learn.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.deletebehavior?view=efcore-5.0
This does require you to remove the many to many relationship yourself or you will receive the following error when you remove a parent entity:
The association between entity types '' and '' has been severed, but
the relationship is either marked as required or is implicitly
required because the foreign key is not nullable. If the
dependent/child entity should be deleted when a required relationship
is severed, configure the relationship to use cascade deletes.
Consider using 'DbContextOptionsBuilder.EnableSensitiveDataLogging' to
see the key values
You can solve this by using DeleteBehavior.ClientCascade instead which will allow EF to perform cascade deletes on loaded entities.
internal class MyContext : DbContext
{
public MyContext(DbContextOptions<MyContext> options)
: base(options)
{
}
public DbSet<Post> Posts { get; set; }
public DbSet<Tag> Tags { get; set; }
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Post>()
.HasMany(p => p.Tags)
.WithMany(p => p.Posts)
.UsingEntity<PostTag>(
j => j
.HasOne(pt => pt.Tag)
.WithMany(t => t.PostTags)
.HasForeignKey(pt => pt.TagId)
.OnDelete(DeleteBehavior.Cascade),
j => j
.HasOne(pt => pt.Post)
.WithMany(p => p.PostTags)
.HasForeignKey(pt => pt.PostId)
.OnDelete(DeleteBehavior.ClientCascade),
j =>
{
j.Property(pt => pt.PublicationDate).HasDefaultValueSql("CURRENT_TIMESTAMP");
j.HasKey(t => new { t.PostId, t.TagId });
});
}
}
public class Post
{
public int PostId { get; set; }
public string Title { get; set; }
public string Content { get; set; }
public ICollection<Tag> Tags { get; set; }
public List<PostTag> PostTags { get; set; }
}
public class Tag
{
public string TagId { get; set; }
public ICollection<Post> Posts { get; set; }
public List<PostTag> PostTags { get; set; }
}
public class PostTag
{
public DateTime PublicationDate { get; set; }
public int PostId { get; set; }
public Post Post { get; set; }
public string TagId { get; set; }
public Tag Tag { get; set; }
}
https://learn.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.deletebehavior?view=efcore-5.0
None of the aforementioned solutions worked for me. What I had to do was use a nullable int (int?) on the foreign key that was not required (or not a not null column key) and then delete some of my migrations.
Start by deleting the migrations, then try the nullable int.
Problem was both a modification and model design. No code change was necessary.
The simple way is to, Edit your migration file (cascadeDelete: true) into (cascadeDelete: false) then after assign the Update-Database command in your Package Manager Console.if it's problem with your last migration then all right. Otherwise check your earlier migration history, copy those things, paste into your last migration file, after that do it the same thing. it perfectly works for me.
You could add this in your DataContext.cs, this works for me...
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();
modelBuilder.Conventions.Remove<ManyToManyCascadeDeleteConvention>();
}
I ran into the same problem and stuck for a long. The following steps saved me.
Go through the constraints and change the onDelete ReferentialAction to NoAction from Cascade
constraints: table =>
{
table.PrimaryKey("PK_table1", x => x.Id);
table.ForeignKey(
name: "FK_table1_table2_table2Id",
column: x => x.table2Id,
principalTable: "table2",
principalColumn: "Id",
onDelete: ReferentialAction.NoAction);
});
I've been wasting two days now to try solve this problem but have yet to find a solution.
In my code that saves an entity with a relationship, I get this error when reaching ctx.SaveChanges():
Unable to determine a valid ordering for dependent operations.
Dependencies may exist due to foreign key constraints, model
requirements, or store-generated values.
Shipment.cs
[ForeignKey("ShipmentNumber")]
public int? DefaultShipmentNumber { get; set; }
public virtual ShipmentNumber ShipmentNumber { get; set; }
ShipmentNumber.cs
[Column("shipment_id")]
[ForeignKey("Shipment")]
public byte ShipmentId { get; set; }
public virtual Shipment Shipment { get; set; }
To avoid circular references, ShipmentNumber belonging to Shipment is nullable (optional), whereas ShipmentNumber's dependency on Shipment is required.
I first create a Shipment, add it and then attach a ShipmentNumber to it and add it to table as well.
Here's the fluent API code:
modelBuilder.Entity<Shipment>()
.HasOptional<ShipmentNumber>((shipment) => shipment.ShipmentNumber)
.WithMany();
Shipment has one "true" ShipmentNumber, but many ShipmentNumbers can link to the same Shipment, hence the WithMany() call (relation without a navigator property). In theory, both relations should always return one entity, but I know EF won't allow me a 1:1 relation here, so I'm using optional.
Here's the actual code:
shipment = tracker.Shipment;
ctx.Shipments.Add(shipment);
shipment.ShipmentNumber = new ShipmentNumber { Number = tracker.ShipmentNumber };
ctx.ShipmentNumbers.Add(shipment.ShipmentNumber);
ctx.SaveChanges();
If someone knows how to make it properly save the entity along with the relation, please do tell. I'm totally stuck at the moment.
Well, I don't know why you want a 1:n relationship in database and a 1:0.1 relationship in the model.
Case 1
If you want to make a 1:1 relationship, you should declare your model as follows:
public class Shipment
{
public int ShipmentId { get; set; }
//NO FK here
public virtual ShipmentNumber ShipmentNumber { get; set; }
}
public class ShipmentNumber
{
public int ShipmentId { get; set; } //ShipmentNumber PK is Also Shipment FK
public virtual Shipment Shipment { get; set; }
}
Mapping:
modelBuilder.Entity<Shipment>()
.HasKey(i => i.ShipmentId);
modelBuilder.Entity<ShipmentNumber>()
.HasKey(i => i.ShipmentId);
modelBuilder.Entity<Shipment>()
.HasRequired(i => i.ShipmentNumber)
.WithRequiredPrincipal(i => i.Shipment)
.WillCascadeOnDelete(false);
Generated Migration:
CreateTable(
"dbo.Shipments",
c => new
{
ShipmentId = c.Int(nullable: false, identity: true),
})
.PrimaryKey(t => t.ShipmentId);
CreateTable(
"dbo.ShipmentNumbers",
c => new
{
ShipmentId = c.Int(nullable: false),
})
.PrimaryKey(t => t.ShipmentId)
.ForeignKey("dbo.Shipments", t => t.ShipmentId)
.Index(t => t.ShipmentId);
Case 2
If you want to make a 1:n relationship:
public class Shipment
{
public int ShipmentId { get; set; }
public virtual ICollection<ShipmentNumber> ShipmentNumbers { get; set; }
}
public class ShipmentNumber
{
public int ShipmentNumberId { get; set; }
public int ShipmentId { get; set; }
public virtual Shipment Shipment { get; set; }
}
Mapping:
modelBuilder.Entity<Shipment>()
.HasKey(i => i.ShipmentId);
modelBuilder.Entity<ShipmentNumber>()
.HasKey(i => i.ShipmentNumberId);
modelBuilder.Entity<Shipment>()
.HasMany(i => i.ShipmentNumbers)
.WithRequired(i => i.Shipment)
.HasForeignKey(i => i.ShipmentId)
.WillCascadeOnDelete(false);
Generated Migration:
CreateTable(
"dbo.Shipments",
c => new
{
ShipmentId = c.Int(nullable: false, identity: true),
})
.PrimaryKey(t => t.ShipmentId);
CreateTable(
"dbo.ShipmentNumbers",
c => new
{
ShipmentNumberId = c.Int(nullable: false, identity: true),
ShipmentId = c.Int(nullable: false),
})
.PrimaryKey(t => t.ShipmentNumberId)
.ForeignKey("dbo.Shipments", t => t.ShipmentId)
.Index(t => t.ShipmentId);
Another problem is the code you are using to add items to database.
ctx.Shipments.Add(shipment);
shipment.ShipmentNumber = new ShipmentNumber { Number = tracker.ShipmentNumber };
//this line is not necessary
ctx.ShipmentNumbers.Add(shipment.ShipmentNumber);
ctx.SaveChanges();
When you add a new Shipment all dependant objects will be inserted to database, if necessary.