Does not contain a definition for 'CreateObjectSet' and no extension method 'CreateObjectSet' in EF6

I am using Entity Framework 6 but the following code is throwing error. The code is migrated from old EF version where it is working fine.

using System.Data.Entity;
using System.Data.Entity.Infrastructure;
using System.Data.Entity.Core.Objects;

using (var context_ = new MyEntities())
{
        ObjectSet<FieldHeader> query = context_.CreateObjectSet<FieldHeader>(); /error on this line
        replaceField(query, dsSet.Tables[0]);
}

Error
Does not contain a definition for 'CreateObjectSet' and no extension method 'CreateObjectSet'

How can I use it in EF6?

as far as i know ObjectSet used to query, add, modify, and delete objects ,

so you need to change your code for adding objects which should be suitable by Ef6 in Ef6 we used DbContext Apis

public IDbSet<Report> Reports { get; set; }

and also ObjectSet was replaced by DbSet but i suggested to change or o switch to the DbContext and DbSet for simpler replaceField function can be rewritten to work with DbSet. any way if you insest to keep your structure you could try these :

  DbSet<FieldHeader> query = context_.Set<FieldHeader>();

replaceField(query, dsSet.Tables[0]);



public void replaceField(DbSet<FieldHeader> query, DataTable dataTable)
{
    foreach (DataRow row in dataTable.Rows)
    {
        int id = Convert.ToInt32(row["Id"]);
        string name = row["Name"].ToString();
        
        FieldHeader existingFieldHeader = query.FirstOrDefault(f => f.Id == id);
        
        if (existingFieldHeader != null)
        {
            existingFieldHeader.Name = name;
        }
        else
        {
            FieldHeader newFieldHeader = new FieldHeader
            {
                Id = id,
                Name = name
            };
            query.Add(newFieldHeader);
        }
    }
    
    context_.SaveChanges(); // Assuming context_ is your DbContext instance
}