Helper for performing COPY (bulk insert and update) operation easily, using Entity Framework + Npgsql.
.Net 4.5, Standard 1.5 and Standard 2.0 are supported.
var uploader = new NpgsqlBulkUploader(context);
var data = GetALotOfData();
// To create a lot of objects
uploader.Insert(data);
// To update a lot of objects
uploader.Update(data);For .Net 4.5 BulkSelect operation is implemented which emulates join in-memory table to DB table. Here is the example:
// We need DbContext first
var context = GetContext();
// Obtained a collection of 50k transactions
var transactions = GetListOfTransction();
// Need to get prices from DB for all transactions, do it with 1 SQL call
var prices = context.Prices.BulkSelect(
x => new { x.Ticker, x.TradedOn }, // need to specify key for JOIN
transactions.Select(x => new { x.Ticker, x.TradedOn }) // obtain key data from local objects
);
// Done, prices variable now contains List<Price> which matches the JOIN DB table to in-memory collectionAvailable on NuGet:
Install-Package Npgsql.Bulk
More info at: http://tsherlock.tech/2017/10/11/solving-some-problems-with-bulk-operations-in-npgsql/