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Seed script in Entity Framework Core is breaking my migration

I have a very simple scenario where I have number of related entities and a couple of them are expected to be prefilled (through seed script). Then, I run my application and it adds a new related data (related to the tables populated by seed script).
And eventually, when I want to add a new migration, for example make a field nullable (of an entity which was not seeded), I try the update-database command and everything breaks up because the migration is trying to recreate my seeded tables. It is impossible because they keep a foreign key.
I will be more specific:
Car (Id, Brand, Color, Year)
many-to-one
CarType (Id, Value)
So, in my DbContext I have the following:
modelBuilder.Entity<CarType>()
.HasData(new CarType('4125ad9e-68fe-4d25-9d73-7e8acc097d6f', 'Coupe'))
And then, I run my application and I start inserting new Cars with the respective types. So, now I have:
Car(1, 'BMW', 'Black', 2011) FK-> CarType('4125ad9e-68fe-4d25-9d73-7e8acc097d6f', 'Coupe')
Car(2, 'Audi', 'Green', 2008) FK-> CarType('cc097d6f9e-68fe-4d25-9d73-4125ad7e8a', 'Estate')
But, one day I decide to make the Year field nullable
public int? Year { get; set; }
I ran add-migration and everything looks fine except for that in the Up statement:
migrationBuilder.DeleteData(
table: "CarType",
keyColumn: "Id",
keyValue: new Guid("4125ad9e-68fe-4d25-9d73-7e8acc097d6f"));
Once I execute update-database I get an error that the operation can not be executed because there's a foreign key related to the entity I am trying to delete:
The DELETE statement conflicted with the REFERENCE constraint
How am I supposed to handle that? My seed scrips are kind of blocking me right now. I want to be able to make changes to my other tables, even on the ones that are seed scripted without the need to recreate stuff.

I think you've records in DB depends on Card Type Id with the same Id you tried to delete
so you can manually delete all dependent entities from DB then apply update database and this not recommended
or
change all entities that have relation with CardType to be "Cascade" in onModelCreating function
example
entity.HasOne(d => d.CardTypes)
.WithMany(p => p.Cards)
.HasForeignKey(d => d.CardTypeId)
.OnDelete(DeleteBehavior.Cascade) /* Cascade */
.HasConstraintName("FK_Cards_CardTypes");

The solution for me was to remove the HasData related seeding from my DbContext because when a migration is added the changes to the data specified with HasData are transformed to calls to InsertData(), UpdateData(), and DeleteData().
So, as suggested HERE, I moved the initialization logic into my initial migration.
migrationBuilder.InsertData(
table: "CarType",
columns: new[] { "Id", "Value" },
values: new object[] { "4125ad9e-68fe-4d25-9d73-7e8acc097d6f", "Coupe" });

How to rename PrimaryKey and ForeignKey in EF Core 3.1?

I recently rename the column name on my DB. When create a new migration and what I see: EF Core immediately drop column and create a new one. It doesn't make sense to me. Is there any rename foreign key or primary key method?

Use "HasConstraintName" fluent API like this :
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Student>()
.HasMany(c => c.Employees)
.WithOne(e => e.Company)
.HasConstraintName("NamFKConstraint");
}

MigrationsModelDiffer is the service class that detects model changes. It "works" by comparing two snapshots of your database model to guess what you changed. Column renames will probably only be detected if nothing else about the column was changed. If you make too many changes at once, then the missing columns will be dropped and new ones added.
If this isn't what you want, you'll need to modify the migration script to specify column renames & other type changes by hand.
migrationBuilder.RenameColumn(
name: "old_name",
table: "table_name",
newName: "new_name");

Entity Framework 6 fluent api delete cascade on n:n relationship [duplicate]

I want to disable cascade deletes for a link table with entity framework code-first. For example, if many users have many roles, and I try to delete a role, I want that delete to be blocked unless there are no users currently associated with that role. I already remove the cascade delete convention in my OnModelCreating:
protected override void OnModelCreating(DbModelBuilder modelBuilder) {
...
modelBuilder.Conventions.Remove<OneToManyCascadeDeleteConvention>();
And then I set up the user-role link table:
modelBuilder.Entity<User>()
.HasMany(usr => usr.Roles)
.WithMany(role => role.Users)
.Map(m => {
m.ToTable("UsersRoles");
m.MapLeftKey("UserId");
m.MapRightKey("RoleId");
});
Yet when EF creates the database, it creates a delete cascade for the foreign key relationships, eg.
ALTER TABLE [dbo].[UsersRoles] WITH CHECK ADD CONSTRAINT [FK_dbo.UsersRoles_dbo.User_UserId] FOREIGN KEY([UserId])
REFERENCES [dbo].[User] ([UserId])
ON DELETE CASCADE
GO
ALTER TABLE [dbo].[UsersRoles] WITH CHECK ADD CONSTRAINT [FK_dbo.UsersRoles_dbo.Role_RoleId] FOREIGN KEY([RoleId])
REFERENCES [dbo].[Role] ([RoleId])
ON DELETE CASCADE
GO
How can I stop EF generating this delete cascade?

I got the answer. :-) Those cascade deletes were being created because of ManyToManyCascadeDeleteConvention. You need to remove this convention to prevent it from creating cascade deletes for link tables:
modelBuilder.Conventions.Remove<ManyToManyCascadeDeleteConvention>();

I believe that turning off ManyToManyCascadeDeleteConvention globally is not a wise option. Instead, it's better to turn it off only for the concerned table.
This can be achieved through editing the generated migration file, for property cascadeDelete. For example:
AddForeignKey("dbo.UsersRoles", "UserId", "dbo.User", "UserId", cascadeDelete: false);

I agree with Ebram Khalil that turning it off for a single table is a good option. I like to stick as close to the automatically built migrations as I can, however, so I would set it up in OnModelCreating:
modelBuilder.Entity<User>()
.HasMany(usr => usr.Roles)
.WithMany(role => role.Users)
.Map(m => {
m.ToTable("UsersRoles");
m.MapLeftKey("UserId");
m.MapRightKey("RoleId");
})
.WillCascadeOnDelete(false);
I believe this preserves the delete going the other direction, so if both needed to be blocked (makes sense in this example) a similar call would need to be made starting with Entity<User>(Role)
Of course, this comes ages after the question was asked. So it may not have been valid in 2012.

This works for me in EFCore 6.0.1 and MySql, according to ms docs.
Note: Don't forget to regenerate your migration files after this.
// In your dbContext class
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder
.Entity<User>()
.HasMany(usr => usr.Roles)
.WithMany(role => role.Users)
.OnDelete(DeleteBehavior.Restrict);
}

Entity Framework 6 trying to drop non existent Index when renaming

As a newcomer to EF migrations, I was surprised by the following behaviour, and wondered if it's intentional (i.e. there's a switch to make it go away).
When I rename a column, I have the following relevant lines inside an EntityTypeConfiguration class:
Property(x => x.MyColumn).HasColumnName(#"MyColumn").HasColumnType("nvarchar").IsOptional();
And, crucially:
HasOptional(a => a.RelatedTable).WithMany(b => b.ThisTable).HasForeignKey(c => c.MyColumn).WillCascadeOnDelete(false);
Which is, as I understand it, establishing a foreign key relationship. When I rename MyColumn to MyColumn2, the migration that is created looks like this:
public override void Up()
{
RenameColumn(table: "dbo.ThisTable", name: "MyColumn", newName: "MyColumn2");
RenameIndex(table: "dbo.ThisTable", name: "IX_MyColumn", newName: "IX_MyColumn2");
}
However, MyColumn is not indexed on ThisTable. I realise that creating indexes for a foreign key relationship is advisable; is this why EF assumes there is one?
Note that the EF model was generated from the DB initially using the EF Reverse POCO Generator.

It's intentional. Code First migrations are based purely on model (data annotations, fluent configuration) and assume the previous database state is created using migration as well. Since EF default convention is to create index for FK columns, the migration assumes that the index exists and tries to rename it.
You can solve it in two ways. Either edit the generated migration and remove the RenameIndex (and other index related commands), or turn off (remove) the default FK index convention:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Conventions.Remove<ForeignKeyIndexConvention>();
// ...
}
Please note that the later will affect your future model modifications and you have to explicitly opt for index on FK columns (which cannot be done if the entity does not have explicit FK property). Also if you rename some of the exiting FK columns which do have an index, you'll have to add RenameIndex (or DropIndex/CreateIndex`) commands manually.

A dependent property in a ReferentialConstraint is mapped to a store-generated column

I get this error when writing to the database:
A dependent property in a ReferentialConstraint is mapped to a
store-generated column. Column: 'PaymentId'.
public bool PayForItem(int terminalId, double paymentAmount,
eNums.MasterCategoryEnum mastercategoryEnum, int CategoryId, int CategoryItemId)
{
using (var dbEntities = new DatabaseAccess.Schema.EntityModel())
{
int pinnumber = 0;
long pinid = 1; //getPinId(terminalId,ref pinnumber) ;
var payment = new DatabaseAccess.Schema.Payment();
payment.CategoryId = CategoryId;
payment.ItemCategoryId = CategoryItemId;
payment.PaymentAmount = (decimal)paymentAmount;
payment.TerminalId = terminalId;
payment.PinId = pinid;
payment.HSBCResponseCode = "";
payment.DateActivated = DateTime.Now;
payment.PaymentString = "Payment";
payment.PromotionalOfferId = 1;
payment.PaymentStatusId = (int)eNums.PaymentStatus.Paid;
//payment.PaymentId = 1;
dbEntities.AddToPayments(payment);
dbEntities.SaveChanges();
}
return true;
}
The schema is:

Is it possible that you defined a bad column relation between your tables?
In my case, I had different columns and one was set as autonumeric.

This error says that you are using unsupported relation or you have error in your mapping. Your code is most probably absolutely unrelated to the error.
The error means that you have some relation between entities where foreign key property in dependent entity is defined as store generated. Store generated properties are filled in the database. EF doesn't support store generated properties as foreign keys (as well as computed properties in primary keys).

I had the same problem. Based on the answers provided here I was able to track it and solve it, but I had a strange issue described below - it might help somebody in the future.
On my dependent tables, the foreign Key columns have been set to StoreGeneratedPattern="Identity". I had to change it to "None". Unfortunately, doing so inside designer didn't work at all.
I looked in the designer-generated XML (SSDL) and these properties were still there so I removed them manually. I also had to fix the columns on the database (remove the Identity(1,1) from CREATE TABLE SQL)
After that, the problem went away.

I had the same problem and after some digging in table design in sql server , I found that mistakenly i set table's primary key also as foreign key.
In this image you can see that JobID is table's primary key but also mistakenly foreign key.

My problem was caused by redundant defining of the Primary key in the configuration.
this
.Property(p => p.Id)
.HasColumnName(#"id")
.IsRequired()
.HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity) // this is redundant when you want to configure a One-to-Zero-or-One relationship
.HasColumnType("int");
Remove this line
.HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity)
Example http://www.entityframeworktutorial.net/code-first/configure-one-to-one-relationship-in-code-first.aspx
This is enough to define the relationship
// Configure Student & StudentAddress entity
modelBuilder.Entity<Student>()
.HasOptional(s => s.Address) // Mark Address property optional in Student entity
.WithRequired(ad => ad.Student); // mark Student property as required in StudentAddress entity. Cannot save StudentAddress without Student

Re-check the relationship between Payment and the other tables/entities. Including the ones that shouldn't contain PaymentId because that's where the problem is most likely hiding.
When creating foreign keys in SQL Server Management Studio, the primary key is defaulted, and this default is reverted when the parent table is changed, so be careful to change values in the correct order in the "Tables and Columns" window.
Also, after you've fixed the problematic relationship, there's a good chance that a simple "Refresh" on the model won't correctly remove the erronous relationship from the model and you'll get the same error even after the "fix", so do this yourself in the model before performing a refresh. (I found this out the hard way.)

If you have checked your relationships and are good there.
Delete the table in the edmx and then update from database. This will save you doing the update manually.

For me it was a wrongly placed foreign key in the table but even after altering the table to fix it, it was still not working. You need to update the EDMX files (and not enough to "refresh" the table from the model, you need to remove and add the table again in the model).

In addition to the accepted answer, if you are using EF Reverse POCO generator or some other tool that generates your POCO's, make sure you regenerate them!

In my case Id field wich FK just in Entity Framework the propierty "StoreGeneratedPattern" was set "Itentity" instead of "None"

In my case the problem was caused by having a two-way 1-1 relationship:
class Foo{
[Key]
Id
[ForeignKey]
BarId
...
}
class Bar{
[Key]
Id
[ForeignKey]
FooId
...
}
I had to simply remove one of the two foreign keys (not necessary anyway).

In my case it was simply that I did not have permissions set properly on the database. I had read only set and Entity framework was giving me a ReferentialConstraint error which threw me off. Added additional write permissions and all was well.

In my case, I had a Database Generated property, and a ForeignKey navigation property set up to reference a 1 to 1 related table.
This wasn't something I could remove, I needed to be able to both set the primary key of the entity to be Database Generated AND I needed to be able to reference the 1 to 1 table as a navigation property.
Not sure if this is the same for others, but this problem was only showing up when creating a new entity, reading or editing existing entities did not exhibit the issue, so I got around the issue by creating an inherited version of my Context and using the Fluent method to switch off the navigation property when creating.
So, my original entity looked like this:
public partial class MyEntity
{
[Key]
[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
public Guid id{ get; set; }
// Navigation
[ForeignKey("id")]
public PathEntity Path { get; set; }
}
So I made a special inherited context that looked like this:
private class _navPropInhibitingContext : EF.ApplicationDBContext
{
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<MyEntity>()
.Ignore(e => e.Path);
}
}
and then changed the code that created the new entity to make user of the new context type
using (var specialContext = new _navPropInhibitingContext())
{
var dbModel = new MyEntity()
{
...
};
specialContext.MyEntity.Add(dbModel);
await specialContext.SaveChangesAsync();
}
Hope this helps somebody

I have the same issue.
Here is my case, if you are adding a new record and has a primary key but is not auto-incremented, this will trigger an error.
I thought first that it will automatically generate the key for me so I leave the Id as blank.
Example:
Customer cust = new Customer();
//cust.Id - I left it blank
db.Customer.Add(cust);
db.SaveChanges();
But upon quick investigation, I forgot to set it's Identity to true and that would trigger an error once you do SaveChanges on your DbContext.
So make sure if your Identity is true or not.

In my case I was passing auto generated primary key of the same table in foreign key column so entity frame work is throwing an error that it can not set a value of that column which is not generated yet as we can only get autogenerated value after save change
Here BonusRequestId is my primary key which I was doing a mistake