Using an ORM like Entity Framework is not efficient to perform bulk operations. To bulk insert efficiently, the SqlBulkCopy
class must be used.
To insert a generic list, it must be converted to a DataTable
:
public static DataTable ConvertToDataTable<T>(IList<T> list)
{
PropertyDescriptorCollection propertyDescriptorCollection = TypeDescriptor.GetProperties(typeof(T));
DataTable table = new DataTable();
for (int i = 0; i < propertyDescriptorCollection.Count; i++)
{
PropertyDescriptor propertyDescriptor = propertyDescriptorCollection[i];
Type propType = propertyDescriptor.PropertyType;
if (propType.IsGenericType && propType.GetGenericTypeDefinition() == typeof(Nullable<>))
{
table.Columns.Add(propertyDescriptor.Name, Nullable.GetUnderlyingType(propType));
}
else
{
table.Columns.Add(propertyDescriptor.Name, propType);
}
}
object[] values = new object[propertyDescriptorCollection.Count];
foreach (T listItem in list)
{
for (int i = 0; i < values.Length; i++)
{
values[i] = propertyDescriptorCollection[i].GetValue(listItem);
}
table.Rows.Add(values);
}
return table;
}
Then the SqlBulkCopy
can be used. In the example, the user table is bulk inserted:
DataTable dt = new DataTable();
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
using (SqlBulkCopy sqlBulkCopy = new SqlBulkCopy(connection))
{
sqlBulkCopy.ColumnMappings.Add("UserID", "UserID");
sqlBulkCopy.ColumnMappings.Add("UserName", "UserName");
sqlBulkCopy.ColumnMappings.Add("Password", "Password");
sqlBulkCopy.DestinationTableName = "User";
sqlBulkCopy.WriteToServer(dt);
}
}