help with writing update of price

Update products with new price todo ( estamte time 3-4 hours work) Hi the project got insert working everyfast. the data is comming form a csv file in batch of max 2000 rows. to check if the products exists in the db you need create a new collections with sql somethin like this "select * from products p inner join products_prices pp on p=productsid = [login to view URL] where storeid = x and csvproductid = IN ( 1,2,3,4... )" then use linq to extract wich rows is for update and wich rows is for insert. instead for updating prices do a new bulkinsert like dataSource = new PostgreSqlDataSource([login to view URL]); var keys = [login to view URL]("products_prices", rows_for_updates).ToInt64List().Execute(); code from the file using System; using [login to view URL]; using [login to view URL]; using [login to view URL]; using [login to view URL]; using [login to view URL]; using [login to view URL]; using Npgsql; namespace csvtodb { class CsvToDatabase { PostgreSqlDataSource dataSource; public bool doUpdateOrInsert( ref List<CSV_ROWS_DATA> records) { // ToDo add update if the products exists already // filed IN CSV_ROWS_DATA idstore and storeproductid use thuse field to check if records exists or not doInsert(ref records); return true; } public doUpdate( ref List<CSV_ROWS_DATA> records ) { } // It can do lest 668 products insert within 4.32 sec public bool doInsert( ref List<CSV_ROWS_DATA> rows) { int productsCount; string strKeys;