In a OneToMany relationship between the entities:
Composer > Soundtrack
Soundtrack > SoundtrackRating
i want to select each Soundtrack by a given Composer and avergage the SoundtrackRatings for each Soundtrack.
In DQL:
SELECT s.name, (SUM(r.rating)/COUNT(r.rating)) AS rating
FROM Soundtrack AS s
LEFT JOIN SoundtrackRating AS r
WHERE s.composer = :composer AND r.soundtrackId = s.id
GROUP BY s.id
ORDER BY rating DESC
Then i'm passing the :composer instance of type Composer:
$em->createQuery($dql)
->setParameter('composer', $composer)
->getResult();
However in the query result i am getting all Soundtrack entries, no matter what $composer i pass as a parameter. The only difference is that only averages the ratings of the given $composer, the rest averages 0.
Where is the problem in this query?
Figured it out. Removing r.soundtrackId = s.id from the WHERE clause and using WITH in the LEFT JOIN instead:
SELECT s.name, (SUM(r.rating)/COUNT(r.rating)) AS rating
FROM Soundtrack AS s
LEFT JOIN SoundtrackRating AS r WITH r.soundtrackId = s.id
WHERE s.composer = :composer
GROUP BY s.id
ORDER BY rating DESC
Related
Here is my query:
ALTER PROCEDURE sp_logdetails
(
#bookid INT
)
AS
BEGIN
SELECT *
FROM book_lending
LEFT OUTER JOIN student ON student.id = book_lending.id
WHERE bookid = #bookid
END
When i execute above query, it shows only book_lending data, not the student data. Here is my screenshot
And it is my student table data screenshot:
May i know, how to get student data in which particular bookid. I used to set foreign key for book_lending id to student id.
Can anyone guide me to fix this?
Thanks,
Select the specific columns from joined table in your select list. Here bl and s is table alias for better redability. You need to select the columns you want and include them to your select list. below query will select all columns from both tables.
SELECT bl.*, s.*
FROM book_lending bl
LEFT OUTER JOIN student s ON s.id = bl.id
AND bl.bookid = #bookid
You got the fields mixed up in the join:
LEFT OUTER JOIN student ON student.id = book_lending.id
You try to match a student to book lending by ID of both - which is wrong.
Change the code to this and you will start getting results back:
SELECT *
FROM book_lending
LEFT OUTER JOIN student ON student.id = book_lending.studentid
WHERE bookid = #bookid
I have a Product Entity which has a ManyToMany relationship with a Taxon Entity. I want to find all the products that belong to the intersection of all Taxons. For instance I want to find all products that belong to taxons with IDs 1 and 2.
Products
{1,2,3}
Taxons
{1,2,3,4,5}
ProductsToTaxons
{{p1,t1},{p1,t2}, {p2,t2}}
I want to retrieve the following set ONLY when querying products for taxons 1 and 2:
Product
{1}
which is from {{p1,t1}, {p1,t2}}
Okay, So here is the DQL that i tried... but it doesn't work?
SELECT p FROM SRCProductBundle:Product p
JOIN p.taxons t
WHERE t.id = 1 AND t.id = 2
(P.S. I would also do this with QueryBuilder with as well)
EDIT
To clarify, here is the SQL that I would like to translate into DQL/QueryBuilder.
select p.id
from product p
where exists (select product_id
from product_to_taxon
where taxon_id = 1
and product_id = p.id)
and exists (select product_id
from product_to_taxon
where taxon_id = 4
and product_id = p.id);
You can use the MEMBER OF statement to achieve this although in my experience it hasn't produced very performant results with a ManyToMany relationship:
In DQL:
SELECT p FROM SRCProductBundle:Product p
WHERE 1 MEMBER OF p.taxons OR 2 MEMBER OF p.taxons
Or with Query builder
$this->createQueryBuilder('p')
->where(':taxon_ids MEMBER OF p.taxons')
->setParameter('taxon_ids', $taxonIdsArray)
->getQuery()
->getResult();
This will create SQL similar to the example provided although in my experience it still had a join in the EXISTS subqueries. Perhaps future versions of Doctrine can address this.
I think you want something like this:
$qb = $this
->createQueryBuilder('p')
->select('p.id')
;
$qb
->leftJoin('p.taxons', 'taxon1', Join::WITH, 'taxon1.id = :taxonId1')
->setParameter('taxonId1', 1)
->andWhere($qb->expr()->isNotNull('taxon1'))
->leftJoin('p.taxons', 'taxon2', Join::WITH, 'taxon2.id = :taxonId2')
->setParameter('taxonId2', 2)
->andWhere($qb->expr()->isNotNull('taxon2'))
;
Which is equivalent to the SQL:
SELECT p.id
FROM products p
LEFT JOIN taxons t1 ON (p.id = t1.product_id AND t1.id = 1)
LEFT JOIN taxons t2 ON (p.id = t2.product_id AND t2.id = 2)
WHERE t1.id IS NOT NULL
AND t2.id IS NOT NULL
;
Your DQL has wrong logic. You can't have a taxon with both id=1 and id=4. You could do it like this:
SELECT p FROM SRCProductBundle:Product p
JOIN p.taxons t
WHERE t.id = 1 OR t.id = 4
But I would prefer this way:
SELECT p FROM SRCProductBundle:Product p
JOIN p.taxons t
WHERE t.id IN (1, 4)
Using query builder that would look something like this, assuming you're in EntityRepository class:
$this->createQueryBuilder('p')
->join('p.taxons', 't')
->where('t.id IN :taxon_ids')
->setParameter('taxon_ids', $taxonIdsArray)
->getQuery()
->getResult();
For lack of a clean way to do this with DQL, and after a considerable amount of research, I resorted to doing this in Native SQL. Doctrine allows Native SQL via the EntityManager with createNativeQuery().
So in short, I utilized this ability and constructed the SQL query included in my question as a string and then passed it to the createNativeQuery() function.
This does appear to have some drawbacks as it appears I will be unable to use the KnpPaginatorBundle with it... So I might end up just filtering the results in PHP rather than SQL, which I'm hesitant to do as I think there are performance drawbacks.
I know that similar question was asked 3 years ago (Doctrine2 Order By before Group By) but maybe from that time something changed.
i have 2 entity propertes:
orderId
orderUpdateDate
both as a pair are set to be unique, but for listing I need last update date so sorting should be
order by orderUpdateDate DESC
and then grouped by orderId so I have orders only once.
group by orderId
problem is such that when I paste both in one query in query builder I got random listing of orders
To achieve such a result you'd have to end up with following SQL query:
SELECT n.id, n.update_date
FROM (
SELECT o.id, o.update_date
FROM orders o
ORDER BY o.update_date DESC
) n
GROUP BY n.id;
Unfortunately Doctrine's DQL doesn't support nested queries in FROM clause. However, it allows you to create a custom, native SQL query that can be mapped by ORM:
$rsm = new ResultSetMappingBuilder($em);
$rsm->addRootEntityFromClassMetadata('MyProject\\Order', 'o');
$sql = sprintf('SELECT %s FROM (SELECT ...) GROUP BY ...', $rsm->generateSelectClause());
$query = $em->createNativeQuery($sql, $rsm);
$result = $query->getResult();
I have three tables: users, projects, user_project
user_project contains user_id, project_id and role_id, where user_id and project_id are both primary keys connected to projects.project_id and users.user_id.
I want to get the the name and surname of all the users from the users table that has to do with a certain project from the projects table through user_project.
What SQL statement do I have to use? I was thinking something like this:
SELECT
users.name, users.surname
FROM users
WHERE users.user_id = user_project.user_id AND projects.project_id = #parameter
I am using SQL Server 2012 and ASP.NET/VB.NET.
Db Diagram:
http://i.imgur.com/lrv52wO.png
SELECT users.name, users.surname
FROM users u
INNER JOIN user_project up
ON u.user_id = up.user_id
WHERE up.project_id = #parameter
You'll need to join to your other tables - either from Users through User_Project all the way to Projects if you want to base your selection on something in the Projects table:
SELECT
u.name, u.surname
FROM users u
INNER JOIN user_project up ON u.user_id = up.user_id
INNER JOIN project p ON p.project_id = up.project_id
WHERE p.project_name = 'something'
or at least to the link table, if you can use the project_id as criteria:
SELECT
u.name, u.surname
FROM users u
INNER JOIN user_project up ON u.user_id = up.user_id
WHERE up.project_id = #parameter
Update: assuming your Role table is connected to Users through again a link table Users_role then you need this to select role name, too:
SELECT
u.name, u.surname,
RoleName = r.Name
FROM users u
INNER JOIN user_project up ON u.user_id = up.user_id
INNER JOIN user_roles ur ON u.user_id = ur.user_id
INNER JOIN role r ON ur.role_id = r.role_id
WHERE up.project_id = #parameter
SELECT
users.name, users.surname
FROM users
inner join user_project
on users.user_id = user_project.user_id
WHERE user_project.project_id = #parameter
This should do it.
SELECT users.name, users.surname
FROM users
INNER JOIN user_project ON user_project.user_id = users.user_id
WHERE (user_project.project_id = #parameter)
The important line here is the line that starts INNER JOIN. You don't need the project table as the project_id column is in user_project. If you wanted to get the project name for example you would need the project table. You would do this by writing another INNER JOIN.
INNER JOIN project ON project.project_id = user_project.project_id
Now that you have joined you can access all the columns in the project table.
I have a table and a relation
I have maybe 10 Submissions, but when I query the database I only want to get those with a Unique CaseId and the one to return should be the one with the newest Date. Is it possible (And adviceable) to do this in a single query or should I do the filtering in my asp.nets code behind where I fetch the data?
Edit: New images
Here you can see that I show many items with the same case id, I only want to show the latest one (Based on date)
This is my current sql query
SELECT Submission.Id, Date, center.Name as CenterName, center.Id as CenterId, subject.Name as SubjectName, subject.Id as SubjectId, EmployeeName, Reason, Description, Explanation, Done, ChiefLevel, Action, CaseId
FROM Submission, subject, center
WHERE center.Id=CenterId AND subject.Id=SubjectId
ORDER BY Date DESC;
SELECT caseid
FROM
(
SELECT caseid, max(date) AS max_date
FROM submission
GROUP BY caseid
) a
JOIN subject t ON a.subjectid=t.id
My QUERY ended up being this
SELECT s.Id, s.Date, c.Name as CenterName, c.Id as CenterId, su.Name as SubjectName, su.Id as SubjectId, s.EmployeeName, s.Reason, s.Description, s.Explanation, s.Done, s.ChiefLevel, s.Action, s.CaseId
FROM submission as s
INNER JOIN
(
SELECT CaseId, MAX(Date) AS MaxDateTime
FROM submission
GROUP BY CaseId
) as groupeds
ON s.CaseId = groupeds.CaseId
AND s.`Date` = groupeds.MaxDateTime
INNER JOIN
(
SELECT Id, Name
FROM subject
) as su
ON su.Id=SubjectId
INNER JOIN
(
SELECT Id, Name
FROM center
) as c
ON c.Id=CenterId;