Oracle treating empty string as NULL problem for a Java / JPA programmer

Question

How do you handle this situation where Oracle stores the empty string as a null in the database ?

I would like it to be stored as an empty string as it is not as NULL, s

Answer 1

try

create index idx_myfield on mytable(nvl(myfield,-1));

select * from mytable where nvl(myfield,-1)=-1;