public class BulkInsertRequest<T>
{
    public IList<T> Entities { get; set; }
    public SqlTransaction Transaction { get; set; }
    public bool UpdateStatistics { get; set; } = false;
    public bool Recursive { get; set; } = false;
    public bool AllowNotNullSelfReferences { get; set; } = false;
    public bool SortUsingClusteredIndex { get; set; } = true;
}

 public static BulkOperationResponse BulkInsertAll<T>(
     this DbContext ctx,
     BulkInsertRequest<T> request)

public class BulkUpdateRequest
{
    public IList Entities { get; set; }
    public string[] UpdatedColumnNames { get; set; }
    public string[] KeyMemberNames { get; set; }
    public SqlTransaction Transaction { get; set; }
    public bool InsertIfNew { get; set; }
}

 public static BulkOperationResponse BulkUpdateAll(
     this DbContext ctx,
     BulkUpdateRequest request)

public class BulkSelectRequest<T>
{
	public BulkSelectRequest(string[] keyPropertyNames, 
				 IList<T> items = null,
				 SqlTransaction transaction = null)
	{
        KeyPropertyMappings = keyPropertyNames.Select(n => new KeyPropertyMapping
            {
                ItemPropertyName = n,
                EntityPropertyName = n
            })
            .ToArray();
        Items = items;
        Transaction = transaction;
    }
    public IList<T> Items { get; set; }
    public KeyPropertyMapping[] KeyPropertyMappings { get; set; }
    public SqlTransaction Transaction { get; set; }
   

    public BulkSelectRequest()
    {
        KeyPropertyMappings = new KeyPropertyMapping[0];
        Items = new T[0];
    }
}

public class KeyPropertyMapping
{
    public string ItemPropertyName { get; set; }
    public string EntityPropertyName { get; set; }

    public static KeyPropertyMapping[] IdentityMappings(string[] names)
    {
        return names.Select(n => new KeyPropertyMapping
        {
            ItemPropertyName = n,
            EntityPropertyName = n
        }).ToArray();
    }
}

/// <summary>
/// Given a set of entities we return the subset of these entities
/// that already exist in the database, according to the key selector
/// used.
/// </summary>
/// <typeparam name="T1">The item collection type</typeparam>
/// <typeparam name="T2">The EF entity type</typeparam>
/// <param name="ctx"></param>
/// <param name="request"></param>
public static IList<T1> BulkSelectExisting<T1,T2>(
    this DbContext ctx,
    BulkSelectRequest<T1> request)

    public class BulkDeleteRequest<T>
    {
        public SqlCondition[] SqlConditions { get; set; }

        public KeyPropertyMapping[] KeyPropertyMappings { get; set; }
        public IList<T> Items { get; set; }
        public SqlTransaction Transaction { get; set; }
        public TimeSpan CommandTimeout { get; set; } = TimeSpan.FromMinutes(1);

        public BulkDeleteRequest(
            SqlCondition[] sqlConditions,
            string[] keyPropertyNames,
            IList<T> items = null,
            SqlTransaction transaction = null)
        {
            SqlConditions = sqlConditions;
            KeyPropertyMappings = KeyPropertyMapping.IdentityMappings(keyPropertyNames);
            Items = items;
            Transaction = transaction;
        }

        public BulkDeleteRequest()
        {
            KeyPropertyMappings = new KeyPropertyMapping[0];
            Items = new T[0];
        }
    }

        /// <summary>
        /// The bulk delete request contains a SqlCondition. It has
        /// a list of column name/column value pairs and will be used
        /// to build an AND where clause. This method will delete any
        /// rows in the database that matches this SQL condition unless
        /// it also matches one of the supplied entities according to
        /// the key selector used.
        ///
        /// !!! IMPORTANT !!!
        /// MAKE SURE THAT YOU FULLY UNDERSTAND THIS LOGIC
        /// BEFORE USING THE BULK DELETE METHOD SO THAT YOU
        /// DO NOT END UP WITH AN EMPTY DATABASE.
        /// 
        /// </summary>
        /// <typeparam name="T1"></typeparam>
        /// <typeparam name="T2"></typeparam>
        /// <param name="ctx"></param>
        /// <param name="request"></param>
        public static void BulkDeleteNotExisting<T1, T2>(
            this DbContext ctx,
            BulkDeleteRequest<T1> request)