I have some urgent issue which I could not find answer for across the

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Asked: June 6, 20262026-06-06T19:05:34+00:00 2026-06-06T19:05:34+00:00

I have some urgent issue which I could not find answer for across the

0

I have some urgent issue which I could not find answer for across the web.

I am using CodeFirst EF 4.3.1 and I am getting an error:
Violation of PRIMARY KEY constraint 'PK_T_CRProviders'. Cannot insert duplicate key in object 'dbo.T_CRProviders'.

My code is:

Models:

public enum CRProviderEnums
{
    PE_Abcd = 0,
    PE_Efgh
}

[Table("T_CRProviders")]
public class CRProvider
{
    [Key]
    [Required]
    public int Enum { get; set; }
    [Required]
    public string Name { get; set; }
}

[Table("T_CRSupportedResources")]
public class CRSupportedResource
{
    [Key]
    public Guid SupportedResourceId { get; set; }
    [Required]
    public CRProvider Provider { get; set; }
}

DbContext:

public class RSContext : DbContext
{
    public DbSet<CRProvider> CRProviders { get; set; }
    public DbSet<CRSupportedResource> CRSupportedResources { get; set; }
}

Table T_CRProviders looks like this: Enum (PK), Name

Table T_CRSupportedResources looks like this: SupportedResourceId (PK), Provider_Enum (FK).

In the database table T_CRProviders I already have a provider with the following values:

Enum: 0 (which is PE_Abcd)
Name: "PE_Abcd"

Now my main() calls a method AddSupportedResource. This method adds to table T_CRSupportedResources a new CRSupportedResource which refers to provider 0 (PE_Abcd). The method looks like this:

public void AddSupportedResource()
    {
        CRSupportedResource supportedResource = new CRSupportedResource()
        {
            SupportedResourceId = Guid.NewGuid(),
            Provider = new CRProvider()
            {
                Enum = (int)CRProviderEnums.PE_Abcd,
                Name = "PE_Abcd"
            }
        };

        using (RSContext myContext = new RSContext())
        {
            myContext.CRSupportedResources.Add(supportedResource);

            myContext.SaveChanges();
        }
    }

I expect that this method will leave table T_CRProviders untouched, and add a new row to table T_CRSupportedResources which will look like this:

SupportedResourceId: DE532083-68CF-484A-8D2B-606BC238AB61
Provider_Enum (FK): 0 (which is PE_Abcd).

Instead, upon SaveChanges, Entity framework also tries to add Provider to the T_CRProviders table, and since such a provider already exists it throws the following exception:

An error occurred while updating the entries.

Violation of PRIMARY KEY constraint 'PK_T_CRProviders'. Cannot insert duplicate key in object 'dbo.T_CRProviders'.

The statement has been terminated.

My question:

How can I instruct the EF not to update table T_CRProviders upon updating table T_CRSupportedResources?

Btw, in the SQL Server I see that table T_CRSupportedResources has a foreign key named FK_RW_TCRSupportedCloudResources_RW_TCRCloudProviders_Provider_Enum and its Update Rule has the value of No Action.