Doctrine Project

[DDC-2381] Pagination query can be simplified when simple joins are applied

Mon, 8 Apr 2013 22:32:03 +0000

Hi.
In mysql db table i have > 200,000 items.
I use native doctrine pagination for paging the items list.
But generated query that gets ids for items list in paging works more then 150 sec on my workstation

SELECT DISTINCT id0 FROM (SELECT m0_.id AS id0, m0_.title AS title1, m0_.text AS text2, m0_.price AS price3, m0_.originalPrice AS originalPrice4, m0_.condition_type AS condition_type5, m0_.image_1 AS image_16, m0_.image_2 AS image_27, m0_.image_3 AS image_38, m0_.image_4 AS image_49, m0_.image_5 AS image_510, m0_.video AS video11, m0_.contact_email AS contact_email12, m0_.contact_name AS contact_name13, m0_.contact_phone AS contact_phone14, m0_.contact_type AS contact_type15, m0_.published AS published16, m0_.type AS type17, m0_.status AS status18, m0_.highlight AS highlight19, m0_.urgent AS urgent20, m0_.topads AS topads21, m0_.period AS period22, m0_.hits AS hits23, m0_.ip AS ip24, m0_.created_at AS created_at25, m0_.updated_at AS updated_at26 FROM milla_message m0_ INNER JOIN milla_currency m1_ ON m0_.currency_id = m1_.id INNER JOIN milla_category m2_ ON m0_.category_id = m2_.id INNER JOIN milla_region m3_ ON m0_.region_id = m3_.id INNER JOIN milla_city m4_ ON m0_.city_id = m4_.id WHERE m0_.status = 1 ORDER BY m0_.published DESC) dctrn_result LIMIT 20 OFFSET 0

source code
https://github.com/doctrine/doctrine2/blob/master/lib/Doctrine/ORM/Tools/Pagination/LimitSubqueryOutputWalker.php#L141

why SELECT DISTINCT %s FROM (%s) dctrn_result ???
why not SELECT DISTINCT m0_.id AS id0 FROM milla_message m0_ WHERE m0_.status = 1 ORDER BY m0_.published DESC LIMIT 20 OFFSET 0

[DDC-2283] Paginator with orderBy in joined data retrieve bad result

Tue, 26 Feb 2013 08:52:40 +0000

entity A have many entity B

If DQL is something like "select A, B from A join B order by A.field1, B.field2"
Then Paginator retrieve different Id by a query like :
"select distinct a.id, a.field1, b.field2 from ( ....) order by a.field1 ASC , b.field2 ASC limit 15 offset 0"

so, if a entity A have 20 entity B (and these sub-entity have all a different b.field2) then there's only 1 A retrieved

[DDC-2236] SUM(..) with Pagination gives incorrect result

Sun, 10 Feb 2013 18:21:58 +0000

https://github.com/whiteoctober/Pagerfanta/issues/69

<?php
$query = $em->getRepository('M\E\Q')
->createQueryBuilder('q')
->select('q', 'SUM(q.price) AS amount')
->where('q.id IN(19, 20, 22)')
->groupBy('q.customer')
;

$pager = new Pagerfanta(new DoctrineORMAdapter($query));
$pager->setMaxPerPage(30);
$pager->setCurrentPage($request->query->get('page', 1));

$result = $pager->getCurrentPageResults();
print_r($result[0]['amount']); // 156.71 - Incorrect

$result = $query->getQuery()->getResult();
print_r($result[0]['amount']); // 553.47
?>

Sql for the above:

SELECT DISTINCT id0 FROM (SELECT q0_.id AS id0, SUM(q0_.price) AS sclr36 FROM Q q0_ WHERE q0_.id IN (19, 20, 22) GROUP BY q0_.customer_id) dctrn_result LIMIT 30 OFFSET 0
SELECT q0_.id AS id0, SUM(q0_.price) AS sclr36 FROM Q q0_ WHERE q0_.id IN (19, 20, 22) AND q0_.id IN ('19') GROUP BY q0_.customer_id
SELECT q0_.id AS id21, SUM(q0_.price) AS sclr36 FROM Q q0_ WHERE q0_.id IN (19, 20, 22) GROUP BY q0_.customer_id

Sql with fetchJoin = false (new DoctrineORMAdapter($query, false))

SELECT q0_.id AS id0, SUM(q0_.price) AS sclr36 FROM Quote q0_ WHERE q0_.id IN (19, 20, 22) GROUP BY q0_.customer_id LIMIT 30 OFFSET 0
SELECT q0_.id AS id0, SUM(q0_.price) AS sclr36 FROM Quote q0_ WHERE q0_.id IN (19, 20, 22) GROUP BY q0_.customer_id

[DDC-2213] Paginator does not work with composite primary key entity

Wed, 23 Jan 2013 21:20:21 +0000

Paginator does not work with composed primary key.

"Single id is not allowed on composite primary key in entity" exception is thrown here
https://github.com/doctrine/doctrine2/blob/master/lib/Doctrine/ORM/Tools/Pagination/WhereInWalker.php#L90

Only first column values are fetched while retrieving primary keys here
https://github.com/doctrine/doctrine2/blob/master/lib/Doctrine/ORM/Tools/Pagination/Paginator.php#L173

[DDC-1958] pager produces wrong results on postgresql

Tue, 9 Apr 2013 20:22:45 +0000

The query build by pager to get the subset of PKs to fetch produces wrong results on potgresql (and probably any database), that conforms to the SQL standard. The standard says, that if you wish to have the results in specific order, then you have to specify that by using an ORDER BY clause. If such a clause is not present the database can return the results in whatever order it sees fit.

Testcase fixtures:

CREATE TABLE test (
    id integer,
    name text
);

INSERT INTO test VALUES (1, 'c');
INSERT INTO test VALUES (2, 'a');
INSERT INTO test VALUES (3, 'e');
INSERT INTO test VALUES (4, 'b');
INSERT INTO test VALUES (5, 'd');
INSERT INTO test VALUES (6, 'a');
INSERT INTO test VALUES (7, 'g');
INSERT INTO test VALUES (8, 'h');
INSERT INTO test VALUES (9, 'e');
INSERT INTO test VALUES (10, 'j');

Passing f.e.

$qb = $this->repository
    ->createQueryBuilder('t')
    ->select('t')
    ->setFirstResult(0)
    ->setMaxResults(5)
    ->addOrderBy('t.name', 'ASC')

to pager produces SQL like this modified for readability

SELECT DISTINCT id FROM (
    SELECT id, name FROM test ORDER BY name
  ) dctrn_result
  LIMIT 5 OFFSET 0

Now there is nothing wrong with this modified query per se, but there is no ORDER BY clause in the outer query so according to the standard the DB can choose whatever order it seems fit. Now mysql chooses the same order, but postgresql does not and it's probably not the only DB doing so.

If you are interested in the results, this is the output I'm seeing:

postgresql: 8,4,1,5,3
mysql : 2,6,4,1,5

I and my coworker came to the standard compliant solution it was also tested on the dataset above on both postgresql and mysql and it produced equal results. We have found only one corner case this won't work and IMHO that can't be fixed. The problem is when you do a sort on a field from a table that is in 1:n relation to the main table.. e.g tables posts and tags, where one post can have a multiple tags and you want your results sorted by a tag.

Recipe for a correct query is:

remember the ORDER BY fields from original query and then remove them
wrap the original query with a DISTINCT query, but add the fields from ORDER BY to the SELECT part of that query and add the whole ORDER BY to the end of it, also add the PK to the order by clause, and add the LIMIT clause
wrap the resulting query into another query and select just the id.

so if I take the example from above the SQL should look like this:

SELECT id FROM (
  SELECT DISTINCT id, name FROM (
    SELECT id, name FROM test
  ) dctrn_result_inner
  ORDER BY name, id LIMIT 5 OFFSET 0
) dctrn_result

[DDC-1935] Not all identifier properties can be found in the ResultSetMapping: id

Sun, 29 Jul 2012 07:40:19 +0000

$qb1 = $em->createQueryBuilder()->select('c.id');
...
$query1 = $qb1->getQuery();

$doctrinePaginator = new \Doctrine\ORM\Tools\Pagination\Paginator($query1);
$doctrinePaginator->count(); => generate error

But works fine with $query2 !

$qb2 = $em->createQueryBuilder()->select('c');
...
$query2 = $qb2->getQuery();

$doctrinePaginator = new \Doctrine\ORM\Tools\Pagination\Paginator($query2);
$doctrinePaginator->count(); => no error

[DDC-1927] Pagination of a SELECT of specific fields results in a RuntimeException

Thu, 18 Apr 2013 20:22:25 +0000

When paginating a DQL string which selects specific fields it results in the following error: PHP Fatal error: Uncaught exception 'RuntimeException' with message 'Not all identifier properties can be found in the ResultSetMapping: id'

NOT working: 'SELECT c.id, c.number FROM Application\Entity\Course c'
WORKING: 'SELECT c FROM Application\Entity\Course c'
WORKING: 'SELECT c, c.id, c.number FROM Application\Entity\Course c'

Setting hydration mode to scalar results makes no difference.

Gist to example code and stack trace: https://gist.github.com/d5cd6d0b0ac28e722dd7

[DDC-1918] Paginator gives strange results in the end of the resultset

Wed, 29 Aug 2012 16:24:13 +0000

Hello,
i've an image and a tag entities, image has a one to many with tags. I was using limit and offset and it was giving 7 images instead of 9 (limit is set to 9) due one image has 3 tags. So i started using paginator to resolve the join-fetch issue. It worked fine at the beginning of the resultset, the problem is at the end (i have 29 images), when i increase the offset.
These are the last 3 calls:

offset 27, distinct query is:

SELECT DISTINCT i0_.id AS id0, i0_.creation_time AS creation_time1 FROM Image i0_ LEFT JOIN Tag t1_ ON i0_.id = t1_.image WHERE i0_.owner = 1 ORDER BY i0_.creation_time DESC LIMIT 9 OFFSET 27

it returns 2 images, correct, so the final query is

SELECT i0_.id AS id0, i0_.name AS name1, i0_.status AS status2, i0_.last_processing AS last_processing3, i0_.creation_time AS creation_time4, i0_.height AS height5, i0_.width AS width6, i0_.layers AS layers7, i0_.foldersize AS foldersize8, i0_.sourcesize AS sourcesize9, i0_.title AS title10, i0_.description AS description11, i0_.originalUrl AS originalUrl12, i0_.private AS private13, i0_.watermark AS watermark14, i0_.favorite AS favorite15, t1_.id AS id16, t1_.tag AS tag17, i0_.owner AS owner18, t1_.image AS image19 FROM Image i0_ LEFT JOIN Tag t1_ ON i0_.id = t1_.image WHERE i0_.owner = 1 AND i0_.id IN (?, ?) ORDER BY i0_.creation_time DESC

with parameters the 2 images id, still correct.

offset 29, distinct query is:

SELECT DISTINCT i0_.id AS id0, i0_.creation_time AS creation_time1 FROM Image i0_ LEFT JOIN Tag t1_ ON i0_.id = t1_.image WHERE i0_.owner = 1 ORDER BY i0_.creation_time DESC LIMIT 9 OFFSET 29

which doesn't get any result, but it still goes on querying without id filter:

and it gets the last 2 images maybe due the fetch join like as i'm not using paginator.