In most languages there is a !=
operator for checking inequality of two
things.
Postgres also supports the synonymous <>
operator for checking inequality.
> select 1 <> 1;
?column?
----------
f
> select true <> false;
?column?
----------
t
> select 'taco' <> 'burrito';
?column?
----------
t
h/t Brian Dunn