PostgreSQL/Constraints/Column Relations
Specifying the column relation
<source lang="sql">
postgres=# postgres=# postgres=# CREATE TABLE products ( postgres(# product_no integer, postgres(# price numeric CHECK (price > 0), postgres(# discounted_price numeric CHECK (discounted_price > 0), postgres(# CHECK (price > discounted_price) postgres(# ); CREATE TABLE postgres=# drop table products; DROP TABLE postgres=# postgres=#
</source>