ZCE certified. How to prepare?

Question

Professional Certification

Dear colleagues. There are several questions about ZCE:
1. How to apply for participation in certification?
2. How to prepare? What materials are best to use?
3. Is it possible to retake the exam and when?

Answer 1

If you add one more row to your table with an example
, then the Rsa97 query will return the wrong answer.
Try this query:

SELECT ID, 
       CATEGORY_ID, 
       TITLE 
  FROM PAGES 
 WHERE TITLE IN (SELECT TITLE FROM PAGES GROUP BY TITLE HAVING COUNT(*)>1) 
 GROUP BY TITLE,
          CATEGORY_ID
HAVING COUNT(*)=1;

Answer 2

SELECT * 
  FROM (
    SELECT `title`
      FROM `table`
      GROUP BY `title`
      HAVING COUNT(DISTINCT `category_id`) > 1
  ) AS `c`
  JOIN `table` AS `t` USING (`title`)