using System;

using System.Collections.Generic;

using System.ComponentModel.DataAnnotations;

using System.Data;

using System.Data.SqlClient;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

using YX.Entity;

namespace YX.DAL.Extenstions

{

    public static class SqlBulkCopyHelper

    {

        public static void BulkInsertAll<T>(IEnumerable<T> entities)

        {

            entities = entities.ToArray();

            var cons = new Sam_DBEntities();

            string cs = cons.Database.Connection.ConnectionString;

            var conn = new SqlConnection(cs);

            conn.Open();

            Type t = typeof(T);

            var bulkCopy = new SqlBulkCopy(conn)

            {

                DestinationTableName = t.Name

            };

            var properties = t.GetProperties().Where(EventTypeFilter).ToArray();

            var table = new DataTable();

            foreach (var property in properties)

            {

                Type propertyType = property.PropertyType;

                if (propertyType.IsGenericType &&

                    propertyType.GetGenericTypeDefinition() == typeof(Nullable<>))

                {

                    propertyType = Nullable.GetUnderlyingType(propertyType);

                }

                table.Columns.Add(new DataColumn(property.Name, propertyType));

            }

            foreach (var entity in entities)

            {

                table.Rows.Add(properties.Select(

                  property => GetPropertyValue(

                  property.GetValue(entity, null), property.PropertyType.Name)).ToArray());

            }

            foreach (DataColumn dc in table.Columns)

            {

                bulkCopy.ColumnMappings.Add(new SqlBulkCopyColumnMapping(dc.ColumnName, dc.ColumnName));

            }

            bulkCopy.WriteToServer(table);

            conn.Close();

        }

        private static bool EventTypeFilter(System.Reflection.PropertyInfo p)

        {

            var attribute = Attribute.GetCustomAttribute(p,

                typeof(AssociationAttribute)) as AssociationAttribute;

            if (attribute == null) return true;

            if (attribute.IsForeignKey == false) return true;

            return false;

        }

        private static object GetPropertyValue(object o, string type)

        {

            if (o == null)

            {

                return DBNull.Value;

            }

            return o;

        }

    }

}

 SqlBulkCopy sbc = new SqlBulkCopy(conPrivate);

 foreach (DataColumn dc in dt.Columns)

    sbc.ColumnMappings.Add(new SqlBulkCopyColumnMapping(dc.ColumnName, dc.ColumnName));