Exception Join is a non-standard syntax for an anti join.
SELECT *
FROM customers
EXCEPTION JOIN orders ON id = customer_idException is not a standard reserved word
The example above is actually standard-confirming because “exception” exception is just understood as an identifier for the table customers. It is interpreted like this:
SELECT *
FROM customers AS exception
JOIN orders ON id = customer_idBy qualifying the columns in the on clause, the ambiguity can be resolved: orders ON customers.id = orders.customer_id.
Prefer Not Exists
The standard SQL syntax for the anti join is Not Exists (example).
Related
Standard Features
F671, “Subqueries in CHECK constraints”
Normative references
Exception Join is not standardized in ISO/IEC 9075-2:2023.
