Using SQL bulk copy with your LINQ-to-SQL datacontext

http://www.codeproject.com/Tips/297582/Using-bulk-insert-with-your-linq-to-sql-datacontex

위에서 퍼온 글입니다. 

Linq To SQL는 많은 장점들을 가지고 있지만 대량 insert에는 약점이 있다. 이러한 약점을 보완하기 위해 DataContext부분을 확정을 했다. 

partial class MyDataContext
{
    partial void OnCreated()
    {
        CommandTimeout = 5 * 60;
    }
 
    public void BulkInsertAll<T>(IEnumerable<T> entities)
    {
        entities = entities.ToArray();
 
        string cs = Connection.ConnectionString;
        var conn = new SqlConnection(cs);
        conn.Open();
 
        Type t = typeof(T);
 
        var tableAttribute = (TableAttribute)t.GetCustomAttributes(
            typeof(TableAttribute), false).Single();
        var bulkCopy = new SqlBulkCopy(conn) { 
            DestinationTableName = tableAttribute.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))).ToArray());
        }
 
        bulkCopy.WriteToServer(table);
        conn.Close();
    }
 
    private 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 object GetPropertyValue(object o)
    {
        if (o == null)
            return DBNull.Value;
        return o;
    }
}