CODEWITHSUNDEEP
mysqlsql-order-by
omg
omg

Reputation: 139862

what's the default order by for this query in MYSQL?

mysql> explain SELECT p.id ID, p.job_desc_title Title, p.url URL, substr(p.posting_date, 1, 10) Date, 
    ->                                         p.job_city_name City,
    ->                                         p.job_state_name State,
    ->                                         b.screen_name Name, b.type Type,f.name Company,IF(g.account_id IS NULL,0,1) Online
    ->                                         FROM postings p
    ->                           LEFT JOIN accounts b on p.account_id=b.id
    ->                           LEFT JOIN companies f on f.id=p.job_cmp_id
    ->                           LEFT JOIN online g ON g.account_id=p.account_id
    ->                           WHERE (MATCH(job_desc,job_desc_title,k_state,k_city,zip) AGAINST('+java' IN BOOLEAN MODE))  AND b.closed=0 AND NOT p.expired 
    ->                           
    ->                           LIMIT 0 , 5
    -> ;
+----+-------------+-------+----------+--------------------------------------------------+--------------------------------------+---------+-----------------+------+-------------+
| id | select_type | table | type     | possible_keys                                    | key                                  | key_len | ref             | rows | Extra       |
+----+-------------+-------+----------+--------------------------------------------------+--------------------------------------+---------+-----------------+------+-------------+
|  1 | SIMPLE      | p     | fulltext | FK_listings,f_postings_city_state_desc_title_zip | f_postings_city_state_desc_title_zip | 0       |                 |    1 | Using where | 
|  1 | SIMPLE      | f     | eq_ref   | PRIMARY                                          | PRIMARY                              | 4       | v3.p.job_cmp_id |    1 |             | 
|  1 | SIMPLE      | g     | eq_ref   | account_id                                       | account_id                           | 4       | v3.p.account_id |    1 | Using index | 
|  1 | SIMPLE      | b     | eq_ref   | PRIMARY                                          | PRIMARY                              | 4       | v3.p.account_id |    1 | Using where | 
+----+-------------+-------+----------+--------------------------------------------------+--------------------------------------+---------+-----------------+------+-------------+
4 rows in set (0.00 sec)

It used to be ordering by relevance,but seems not now.

Upvotes: 1

Views: 2423

Answers (2)

CSharpAtl
CSharpAtl

Reputation: 7512

Dont assume an order, if you need it in an order, use the ORDER BY clause.

Upvotes: 2

Eric Petroelje
Eric Petroelje

Reputation: 60498

Without an order by, the "default" ordering will depend on which indexes are used in the query and in what order they are used. This could change as the data/statistics change and the optimizer chooses different plans.

If you want the data in a specific order, use ORDER BY. But I'm sure you already knew that :)

Upvotes: 5

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