As a side note, in Oracle a NULL and an empty string '' are equal, which means that:
'' IS NULL, the expression '' = '' would always evaluate False, and the expression 'A' > '' would be False.
Be mindful of that if you have something like an SSIS package that is sourcing data from Oracle into SQL Server.
"Do not seek to follow in the footsteps of the wise. Instead, seek what they sought." - Matsuo Basho