I wrote a code sample that demonstrates how to perform bulk updates from data read from SQL-Server into a DataTable then sent back to a SQL-Server table that when executed will do all CRUD operations in one statement.

Required to run, VS2015 or higher, SQL-Server installed, life will be easier but not needed to have SSMS (SQL-Server Management Studio).

Download, execute the SQL script to generate the sample database, change the server name in the connection string in DataOperations class in the main project (there is also a class project). Build, run, inspect results. Once you have done that, modified the SELECT statement in DataOperations and remove TOP 8, run again.

Once you have played with the code I'm sure you will come up with variations of the code presented e.g. perhaps you only want added records so remove the update and delete etc. Always backup your database before working with the code presented while my code will restore itself thus no lose of data.

VB.NET sample
C# sample