Why is this an issue?
Since ANSI SQL-92, explicit joins using the
JOIN keyword have been possible, and are preferred. Therefore table joins should be done
with help of the one of the following clauses:
LEFT OUTER JOIN,
FULL OUTER JOIN. The old way to join tables is deprecated and should not be used anymore.
Noncompliant code example
FROM PARTS, PRODUCTS
WHERE PARTS.PROD = PRODUCTS.PROD
INNER JOIN PRODUCTS ON PARTS.PROD = PRODUCTS.PROD