Functions to work with NULL #
All functions are located in the public schema, which is default.
any coalesce(...)
#
Return a first non-null argument.
select coalesce(null, 1, null, 2);
[1]
any nullif(a, b)
#
Return a null value if a equals b, otherwise, it returns a.
select nullif(1, 1);
[null]