SqlBulkCopy: Add RowsCopied Property

[fowl2]

It is is difficult to find out how many rows SqlBulkCopy.WriteToServer[Async] has copied. This is a problem when using streaming as DbDataReader doesn't provide this information either.

Describe the solution you'd like

class SqlBulkCopy
{
...
  public long RowsCopied { get; }
...
}

It would be cleaner to change the return type of WriteToServer[Async] to long, but I think this would technically be a breaking change? This would also have the advantage of not having to worry about multiple calls or reads before writing.

Describe alternatives you've considered

• setting NotifyAfter to 1, subscribing to SqlRowsCopied and then storing it somewhere from the event handler. Cons: overhead of calling a delegate, plus the allocation of EventArgs per row.
• fully buffer to a DataTable. Cons: whole dataset in memory.
• wrapping IDataReader and keeping count of the number of times Read() is called. Cons:
  doesn't work for async readers.
• wrapping DbDataReader. Cons: lots of boilerplate, can't call protected methods on the source leading to unintended behaviour divergence.
• SELECT COUNT(*) FROM DESTINATION. Cons: network round trip, concurrency issues.
• Reflecting on the private _rowsCopied field. Cons: reflection, brittle.

Additional context

• https://social.msdn.microsoft.com/Forums/sqlserver/en-US/9f83c487-d165-4a9e-a701-d0971de25c4f/c-net-sqlbulkcopy-inserted-row-count?forum=sqlintegrationservices
• https://stackoverflow.com/questions/1188384/sqlbulkcopy-row-count-when-complete

[cheenamalhotra]

Hi @fowl2

Thanks for bringing up the request. We'll investigate more and come back to you!

[juliusfriedman]

This is a good suggestion, we currently use reflection to access this field because we don't wan't to have the overhead of an event for every row copied just to get the count.

[cheenamalhotra]

@fowl2 @juliusfriedman

#404 is same issue we addressed with PR #409 .
The API will be part of next release.