Cannot insert duplicate key in object 'dbo.VersionMasters'.The duplicate key value is (0). The statement has been terminated

Question

Hi,

While I am executing the following query, I am getting error "Cannot insert duplicate key in object 'dbo.VersionMasters'.The duplicate key value is (0).
The statement has been terminated."

using (var context = new Entities())
{

var testCaseEntity = new VersionMaster()
{
TestCaseID = testCaseId,
IsDeleted = false,
SupportedVersionId = versionInfo.VersionID
};
context.VersionMasters.Add(testCaseEntity);
}

In 'VersionMasters' table, ID is primary key. Although I am not inserting ID in the above query, I am not getting why I am getting this error.
Please do let me know what I am doing wrong, Kindly waiting for your response.

Thanks,
Santosh

Answer 1

You didn't provide your database table. But I assume your code is expecting the ID to be an IDENTITY field and it is not setup correctly in the database.

Answer 2

Try running DBCC CHECKIDENT on the table.

Answer 3

If you are still having issues, here is an example to try using LocalDb

public class VersionMaster  
{  
    public int TestCaseID { get; set; }  
    public bool IsDeleted { get; set; }  
}  

DbContext where the key is telling EF your primary key entity.HasKey(e => e.TestCaseID);.

public class SampleContext : DbContext  
    {  
        public DbSet<VersionMaster> VersionMaster { get; set; }  
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)  
        {  
            optionsBuilder.UseSqlServer(  
                @"Server=(localdb)\mssqllocaldb;" +   
                "Database=EFSaving.ForumData;Trusted_Connection=True");  
        }  
        protected override void OnModelCreating(ModelBuilder modelBuilder)  
        {  
            modelBuilder.ApplyConfiguration(new VersionMasterConfiguration());  
        }  
        public partial class VersionMasterConfiguration : IEntityTypeConfiguration<VersionMaster>  
        {  
            public void Configure(EntityTypeBuilder<VersionMaster> entity)  
            {  
                entity.HasKey(e => e.TestCaseID);  
            }  
        }  
    }  

Model

public class VersionMaster  
{  
    public int TestCaseID { get; set; }  
    public bool IsDeleted { get; set; }  
}  

Run with

using (var context = new SampleContext())  
{  
    context.Database.EnsureDeleted();  
    context.Database.EnsureCreated();  
  
    List<VersionMaster> list = new()  
    {  
        new () { IsDeleted = false },  
        new () { IsDeleted = false },  
        new () { IsDeleted = false },  
    };  
  
    context.AddRange(list);  
    Console.WriteLine(context.SaveChanges());  
  
}