yes it's my secondary language.

I am sorry for the misuse. about equals empty string and null...
https://db.apache.org/torque/torque-3.3/version-specific/database-howtos/oracle-howto.html
you'll be surprised

I ve been doing database normalisation longer than you've been alive;" why you discuss about this issue with me? The use of NULL is true for Oratsle but not true for all DB. In another DB empty string is it not NULL

1)SELECT on the table that has a value of NULL will result in FULL SCAN 2)try null = null or null + 4 3)look for database normalization

NULL is not indexed use NULL in arithmetic, string, logical and others operations is incorrect its use is the result of a incorrect designing database.