using (var context = new RcoreContext())
{
   // creates a Command
   var command = context.Database.Connection.CreateCommand();
   command.CommandType = commandType;
   command.CommandText = sql;

   using (SqlDataReader reader = command.ExecuteReader())
    {
        while (reader.Read())
        {
        for (int i = 0; i < reader.FieldCount; i++)
        {
            Console.WriteLine(reader.GetValue(i));
        }
        Console.WriteLine();
        }
    }
}

_dbContext.Database.ExecuteSqlCommand(sql, parameters);
_dbContext.Database.SqlQuery<TEntity>(sql, parameters);

using (var connection = context.Database.GetDbConnection())
    using (var command = context.Database.GetDbConnection().CreateCommand())
    {
       command.CommandText = string.Format(sqlQuery, id);
       connection.Open();
       using (var reader = command.ExecuteReader()){}
    }

using (var connection = new SqlConnection(_dbContext.Database.Connection.ConnectionString))
using (var cmd = new SqlCommand())
{
      cmd.Connection = connection;
      cmd.CommandText = "your query here";
      cmd.CommandType = CommandType.Text;

      cmd.Parameters.Add("@param1", SqlDbType.Int);

      cmd.Connection.Open();
      cmd.ExecuteNonQuery();
}