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You may be interested in the USING clause SQL-92 added for foreign keys where the referencing columns have the same name as the referenced columns: JOIN b USING
by dmfay 6y ago
You may be interested in the USING clause SQL-92 added for foreign keys where the referencing columns have the same name as the referenced columns: JOIN b USING (a_id). The only major RDBMS that doesn't support it is SQL Server afaik.
- JoelJacobson 6y agoYes, I know about USING, and you probably know about the one big issue it has; if you add a column name with the same name to some table included, then you get an error due to the ambiguity. Example: SELECT language.name, COUNT(*) FROM rental JOIN customer USING (customer_id) JOIN address USING (address_id) JOIN city USING (city_id) JOIN country USING (country_id) JOIN inventory USING (inventory_id) JOIN film USING (film_id) JOIN language USING (language_id) WHERE country.country = 'Sweden' GROUP BY language.name Works fine, but if we do ALTER TABLE rental ADD address_id integer; Then we get ERROR: common column name "address_id" appears more than once in left table The foreign key based join approach doesn't suffer from this problem, since there which columns to join on is explicit and stable.