How to use DBAL query builder to build this subquery? - mysql

I have this query with subquery.
SELECT * FROM
(SELECT module_id FROM an_modules AS m LIMIT 20 OFFSET 0) AS m
LEFT JOIN an_module_sites AS ms ON (m.module_id = ms.module_id)
How to use DBAL to build subquery like this?
This doesn't seem to be work.
$qb->select('*')
->from(
$qb->select('module_id')
->from($this->Db->getTableName('modules'), 'm')
, 'm')
->leftJoin('m', $this->Db->getTableName('module_sites'), 'ms', 'm.module_id = ms.module_id');
$stmt = $qb->execute();
$result = $stmt->fetchAll();

I recently needed to do this to implement a pagination/sorting helper. As part of this I would take a querybuilder executed by my model and and generically count the total rows it would produce if unlimited.
To be cross platform I couldn't use rowCount and potential grouping meant I couldn't just change the fields in the select - so the best option was to remove the limits and count it as a subquery. This is what I came up with:
<?php
$totalResults = $qb->getConnection()->createQueryBuilder()
->select('COUNT(*)')
->from(
'('
.$qb
->setFirstResult(null)
->setMaxResults(null)
->resetQueryPart('orderBy')
->getSQL()
.')',
'tmp')
->execute()
->fetch(\PDO::FETCH_COLUMN);
I'm not sure how doctrine ORM handles this, but in pure DBAL at least this seems to work.

Related

How to speed up this nested eloquent query in Laravel?

I have an eloquent carry that has to filter through 30+ million records. Everything goes well speed wise.. but whenever i try to do a nested filter query it will keep loading and loading until it crashes...
This is the query:
Balance::orderBy('id', 'asc')->maincheck()->simplePaginate(300);
this below is the same query but without the "simplePaginate" behind it
SELECT *
FROM `balances`
WHERE ((
`balances`.`balanceable_type` = ?
AND EXISTS(SELECT *
FROM `balance_accounts`
WHERE `balances`.`balanceable_id` = `balance_accounts`.`id`
AND `maincheck` = ?)
))
ORDER BY `id` ASC
Does someone have an idea on how to fix this with an other way. I have tried using chunks but it sucks. I have to use eloquent.
Subselect will be significantly slower in this case as it will execute N queries.
You can try using JOIN instead but make sure there is a foreign key between balance_accounts.id and balances.balanceable_id and balanceable_type is indexed:
SELECT *
FROM `balances`
INNER JOIN `balance_accounts`
ON `balance_accounts`.`id` = `balances`.`balanceable_id`
AND `maincheck` = ?
WHERE `balances`.`balanceable_type` = ?
ORDER BY `id` ASC
I'm not really sure if this can be implemented with Eloquent filters but you can easily achieve it using Eloquent query builder.

How to use pagination on DB::select(query) - Laravel

i have some query and i just know how to query on mysql (phpmyadmin)
i got information if using DB::select we cannot to use paginate, so we need change to DB::table(some query) to using pagination.
but the problem is i am confuse how to convert my query into DB::table(some query)
Here is my code
$daily = DB::select("
SELECT
employees.employee_name,
COUNT(DISTINCT DATE(attendance.attendance_datetime)) as jumlah,
locations.location_name,
TIME(MIN(attendance.attendance_datetime)) as check_in,
CASE
WHEN ISNULL(TIME(MIN(attendance.attendance_datetime))) THEN attendance_absence.remarks
WHEN TIME(MIN(attendance.attendance_datetime)) > '08:05:00' THEN (SELECT TIMEDIFF('08:05:00', MIN(TIME(attendance_datetime))))
WHEN TIME(MIN(attendance.attendance_datetime)) <= '08:05:00' THEN 'Good'
ELSE 'No Record'
END as detail_telat,
attendance_absence.remarks as remarks
FROM
employees
LEFT JOIN attendance ON employees.employee_name = attendance.attendance_name AND DATE(attendance.attendance_datetime) = '$date'
LEFT JOIN locations ON employees.location_id = locations.id
LEFT JOIN attendance_absence ON attendance_absence.employee_name = employees.employee_name AND attendance_absence.absences_date = '$date'
WHERE locations.location_name LIKE '%'
GROUP BY employees.employee_name
ORDER BY employees.employee_name
")->paginate(3);
please help me to convert my query into eloquent or query builder, or any suggestion ?
Currently, pagination operations that use a groupBy statement cannot be executed efficiently by Laravel. If you need to use a groupBy with a paginated result set, it is recommended that you query the database and create a paginator manually.
Check documentation

Doctrine2 DBAL Exists query

I would like to ask for your help with Doctrine2 DBAL query built with QueryBuilder. I'm used to ORM, but I think it's an overkill for such query which is being called in a listener.
I need a query with SELECT EXISTS and I don't know how I can construct it using DBAL QueryBuilder.
I have a subquery already created:
$subQuery = $connection->createQueryBuilder();
$subQuery
->select('o.id')
->from('order', 'o')
->leftJoin('o', 'payment', 'p')
->where($subQuery->expr()->isNull('p.id'))
;
I basically want to check if there are any unpaid orders. I now have no idea how to build the SELECT EXISTS query? Can anyone point me in the right direction? I was thinking about something like this:
$qb->select('EXISTS(?)')->setParameter($subQuery->getDQL())
Will that be the correct solution?
#EDIT
After a while of thinking I decided to use ORM instead. Unfortunately that did not work either, I'm getting an error:
line 0, col 7: Error: Expected known function, got 'EXISTS'
The DQL is:
SELECT EXISTS(<subquery here>)
It is a bit weird considering that It has been build with QueryBuilder:
/* #var $qb QueryBuilder */
$qb = $this->em->createQueryBuilder();
$qb
->select($qb->expr()->exists($subQuery->getDQL()));
A few years late, but you need to specify your EXISTS subquery SQL within the SELECT or WHERE statement portion of the QueryBuilder, as opposed to using a parameter.
Additionally since order is a reserved word in MySQL, you will need to use identifier quotes ` (back-tick) to escape the table name.
When using the ORM; you must specify a FROM statement that references an entity, so you would need to change your approach.
$connection = $this->em->getConnection();
$expr = $connection->getExpressionBuilder();
$qbSub = $connection->createQueryBuilder()
->select('1')
->from('`order`', 'o')
->leftJoin('o', '`payment`', 'p', $expr->eq('p.order_id', 'o.id'))
->where($expr->isNull('p.id'));
/**
* #return string "1" if a record exists, "0" otherwise
*/
$connection->createQueryBuilder()
->select('EXISTS(' . $qbSub->getSQL() . ')')
->execute()
->fetchColumn();
Resulting SQL
SELECT EXISTS(
SELECT 1
FROM `order` AS o
LEFT JOIN `payment` AS p
ON p.order_id = o.id
WHERE p.id IS NULL
);
Note: If you have any parameters, the values for the placeholders must be bound using QueryBuilder::setParameter() on the top-level
query, not the sub-queries.
$qbSub = $connection->createQueryBuilder()
->select('1')
->from('`order`', 'o')
->leftJoin('o', '`payment`', 'p', $expr->andX(
$expr->eq('p.order_id', 'o.id'),
$expr->eq('p.name', ':name') // subquery placeholder
))
->where($expr->isNull('p.id'));
$connection->createQueryBuilder()
->select('EXISTS(' . $qbSub->getSQL() . ')')
->setParameter('name', $value) // subquery placeholder param value
->execute()
->fetchColumn();
However, I suggest changing your query from an exclusion join to an inclusion join with NOT EXISTS. Doing so will filter orders that have been paid, out of your result-set. Instead of attempting to join every order on every payment and retrieve the payments that return null. Dramatically improving the performance of the query.
Example db-fiddle
SELECT EXISTS (
SELECT 1
FROM `order` AS o
WHERE NOT EXISTS(
SELECT NULL
FROM `payment` AS p
WHERE p.order_id = o.id
)
)

INNER JOIN Results from Select Statement using Doctrine QueryBuilder

Can you use Doctrine QueryBuilder to INNER JOIN a temporary table from a full SELECT statement that includes a GROUP BY?
The ultimate goal is to select the best version of a record. I have a viewVersion table that has multiple versions with the same viewId value but different timeMod. I want to find the version with the latest timeMod (and do a lot of other complex joins and filters on the query).
Initially people assume you can do a GROUP BY viewId and then ORDER BY timeMod, but ORDER BY has no effect on GROUP BY, and MySQL will return random results. There are a ton of answers out there (e.g. here) that explain the problem with using GROUP and offer a solution, but I am having trouble interpreting the Doctrine docs to find a way to implement the SQL with Doctrine QueryBuilder (if it's even possible). Why don't I just use DQL? I may have to, but I have a lot of dynamic filters and joins that are much easier to do with QueryBuilder, so I wanted to see if that's possible.
Sample MySQL to Reproduce in Doctrine QueryBuilder
SELECT vv.*
FROM view_version vv
#inner join only returns where the result sets overlap, i.e. one record
INNER JOIN (
SELECT MAX(timeMod) maxTimeMod, viewId
FROM view_version
GROUP BY viewId
) version ON version.viewId = vv.viewId AND vv.timeMod = version.maxTimeMod
#join other tables for filter, etc
INNER JOIN view v ON v.id = vv.viewId
INNER JOIN content_type c ON c.id = v.contentTypeId
WHERE vv.siteId=1
AND v.contentTypeId IN (2)
ORDER BY vv.title ASC;
Theoretical Solution via Query Builder (not working)
I am thinking that the JOIN needs to inject a DQL statement, e.g.
$em = $this->getDoctrine()->getManager();
$viewVersionRepo = $em->getRepository('GutensiteCmsBundle:View\ViewVersion');
$queryMax = $viewVersionRepo->createQueryBuilder()
->addSelect('MAX(timeMod) AS timeModMax')
->addSelect('viewId')
->groupBy('viewId');
$queryBuilder = $viewVersionRepo->createQueryBuilder('vv')
// I tried putting the query in a parenthesis, to no avail
->join('('.$queryMax->getDQL().')', 'version', 'WITH', 'vv.viewId = version.viewId AND vv.timeMod = version.timeModMax')
// Join other Entities
->join('e.view', 'view')
->addSelect('view')
->join('view.contentType', 'contentType')
->addSelect('contentType')
// Perform random filters
->andWhere('vv.siteId = :siteId')->setParameter('siteId', 1)
->andWhere('view.contentTypeId IN(:contentTypeId)')->setParameter('contentTypeId', $contentTypeIds)
->addOrderBy('e.title', 'ASC');
$query = $queryBuilder->getQuery();
$results = $query->getResult();
My code (which may not match the above example perfectly) outputs:
SELECT e, view, contentType
FROM Gutensite\CmsBundle\Entity\View\ViewVersion e
INNER JOIN (
SELECT MAX(v.timeMod) AS timeModMax, v.viewId
FROM Gutensite\CmsBundle\Entity\View\ViewVersion v
GROUP BY v.viewId
) version WITH vv.viewId = version.viewId AND vv.timeMod = version.timeModMax
INNER JOIN e.view view
INNER JOIN view.contentType contentType
WHERE e.siteId = :siteId
AND view.contentTypeId IN (:contentTypeId)
ORDER BY e.title ASC
This Answer seems to indicate that it's possible in other contexts like IN statements, but when I try the above method in the JOIN, I get the error:
[Semantical Error] line 0, col 90 near '(SELECT MAX(v.timeMod)': Error: Class '(' is not defined.
A big thanks to #AdrienCarniero for his alternative query structure for sorting the highest version with a simple JOIN where the entity's timeMod is less than the joined table timeMod.
Alternative Query
SELECT view_version.*
FROM view_version
#inner join to get the best version
LEFT JOIN view_version AS best_version ON best_version.viewId = view_version.viewId AND best_version.timeMod > view_version.timeMod
#join other tables for filter, etc
INNER JOIN view ON view.id = view_version.viewId
INNER JOIN content_type ON content_type.id = view.contentTypeId
WHERE view_version.siteId=1
# LIMIT Best Version
AND best_version.timeMod IS NULL
AND view.contentTypeId IN (2)
ORDER BY view_version.title ASC;
Using Doctrine QueryBuilder
$em = $this->getDoctrine()->getManager();
$viewVersionRepo = $em->getRepository('GutensiteCmsBundle:View\ViewVersion');
$queryBuilder = $viewVersionRepo->createQueryBuilder('vv')
// Join Best Version
->leftJoin('GutensiteCmsBundle:View\ViewVersion', 'bestVersion', 'WITH', 'bestVersion.viewId = e.viewId AND bestVersion.timeMod > e.timeMod')
// Join other Entities
->join('e.view', 'view')
->addSelect('view')
->join('view.contentType', 'contentType')
->addSelect('contentType')
// Perform random filters
->andWhere('vv.siteId = :siteId')->setParameter('siteId', 1)
// LIMIT Joined Best Version
->andWhere('bestVersion.timeMod IS NULL')
->andWhere('view.contentTypeId IN(:contentTypeId)')->setParameter('contentTypeId', $contentTypeIds)
->addOrderBy('e.title', 'ASC');
$query = $queryBuilder->getQuery();
$results = $query->getResult();
In terms of performance, it really depends on the dataset. See this discussion for details.
TIP: The table should include indexes on both these values (viewId and timeMod) to speed up results. I don't know if it would also benefit from a single index on both fields.
A native SQL query using the original JOIN method may be better in some cases, but compiling the query over an extended range of code that dynamically creates it, and getting the mappings correct is a pain. So this is at least an alternative solution that I hope helps others.

How can I optimize this raw SQL and perhaps implement it via CodeIgniter?

It's been a while since I've written raw SQL, I was hoping someone could help me out in optimizing this SQL query so that it works across, both, MySQL and PostgreSQL.
I would also have to implement this via CodeIgniter (2.x) using ActiveRecord, any help/advice?
SELECT *
FROM notaries, contact_notaries
WHERE notaries.id = contact_notaries.notary_id
AND WHERE ( contact_notaries.city LIKE %$criteria%
OR contact_notaries.state LIKE %$criteria
OR contact_notaries.address LIKE %$criteria%)
Thanks!
Each query can have just one WHERE clause (you don't need the second)
It's much better to put join condition into JOIN rather then WHERE.
Are you sure you really need all the columns from 2 tables (*)?
So I'd refactor it to
SELECT [field_list]
FROM notaries
INNER JOIN contact_notaries ON (notaries.id = contact_notaries.notary_id)
WHERE ( contact_notaries.city LIKE '%$criteria%'
OR contact_notaries.state LIKE '%$criteria'
OR contact_notaries.address LIKE '%$criteria%')
Using a1ex07's query:
SELECT [field_list]
FROM notaries
INNER JOIN contact_notaries ON (notaries.id = contact_notaries.notary_id)
WHERE ( contact_notaries.city LIKE '%$criteria%'
OR contact_notaries.state LIKE '%$criteria'
OR contact_notaries.address LIKE '%$criteria%')
Active record:
$this->db->select(); // Leave empty to select all fields
$this->db->join('contact_notaries', 'notaries.id = contact_notaries.notary_id', 'inner');
$this->db->like('contact_notaries.city', 'criteria');
$this->db->like('contact_notaries.state', 'criteria');
$this->db->like('contact_notaries.address', 'match');
$results = $this->db->get('notaries');
To specify a list of fields you can do $this->db->select('field_1, field_2, ...');.
http://codeigniter.com/user_guide/database/active_record.html