Convert full path to filename.

sql-snippet-filename-from-path.sql

-- Convert full path to filename.
-- i.e. \\mycompany.com\bigshare\apps\MyApp\outbound\ClientID\ReportType.ClientID.20190529.csv
-- to   ReportType.ClientID.20190529.csv
DECLARE @searchFromRight VARCHAR(MAX) = REVERSE(@filename);
DECLARE @pathCharIndex BIGINT = COALESCE(CHARINDEX('\', @searchFromRight), CHARINDEX('/', @searchFromRight), 0);
--IF NOT (@pathCharIndex BETWEEN 27 AND 60)
--	THROW 51000, 'Could not convert full path to filename.', 1;

SET @filename = SUBSTRING(@filename, LEN(@filename) - @pathCharIndex + 2, @pathCharIndex - 1)