BulkInsertOrUpdate throws "Cannot update identity column" exception

[ssujithsnair]

Below code (simulated to show relevant parts) throw "Cannot update identity column 'ModelID'" exception.

class Model
{
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        [Column("ModelID")]
        public int ModelId { get; set; }

	public DateTime ModelDate { get; set; }
	public int EntityId { get; set; }

        [Column("EntityTypeID")]
        public int EntityTypeId { get; set; }

	[Column("DataTypeID")]
        public int DataTypeId { get; set; }

        // More fields
}

Context

builder.Entity<Model>(entity =>
{
	entity.HasKey(p => p.ModelId);
	entity.Property(p => p.ModelId).UseSqlServerIdentityColumn();
});

Insert/Update code

var updateByProperties = new List<string> { nameof(Model.ModelDate), nameof(Model.EntityId), nameof(Model.EntityTypeId), nameof(Model.DataTypeId) };
context.BulkInsertOrUpdate(modelList, new BulkConfig { UpdateByProperties = updateByProperties } });

// Properties given in UpdateByProperties should be used to match records. It's unique key on table.
// The inserted entries have ModelId set to zero
// BulkInsertOrUpdate (Or BulkUpdate) throws "Cannot update identity column 'ModelID'"

I also tried below as well based on certain suggestions I saw regarding this topic for Entity framework core - but didn't help

entity.HasAlternateKey(x => x.ModelId).HasName("ModelID");
entity.Property(p => p.ModelId).ValueGeneratedOnAdd(); // this should have same effect as UseSqlServerIdentityColumn though

I also tried SetOutputIdentity, KeepIdentity even though it didn't look like related to the issue.

If I do not include UpdateByProperties, it doesn't throw any exception but it doesnt work as expected.
BulkUpdate does nothing while BulkInsertOrUpdate does an insert which is not the expectation.

[borisdj]

You should also set PropertiesToExclude with ModelId, so

var updateByProp = new List<string> { nameof(Model.ModelDate), nameof(Model.EntityId), nameof(Model.EntityTypeId), nameof(Model.DataTypeId) };
var propToExclude = new List<string> { nameof(Model.ModelId) };
var config = new BulkConfig { UpdateByProperties = updateByProp, PropertiesToExclude = propToExclude };
context.BulkInsertOrUpdate(modelList, config);

Additinaly you don't need any of the PK config since EF by convention makes Identity column if one is named Id/ID or TableNameId/ID.
So Attributes [Key], [DatabaseGenerated] can be removed as well as code from builder regarding the same.

PS
When adding code snippets into the comment use code formatting segment for C# for better readability.
```C#
// code goes here
```
I have edited(formatted) your question accordingly.

[ssujithsnair]

That worked, Appreciate the help, Thank you.