Working with Drupal 6, my goal is to order a set of threaded comments similar to how Facebook outputs comments: with the 'anchor' or first comment in each thread sorted DESC, and any 'internal' thread replies sorted ASC so the newest comments are at the bottom.
Here's the SQL query from comment_render, with ordering by COMMENT_ORDER_NEWEST_FIRST:
SELECT c.cid as cid, c.pid, c.nid,
c.subject, c.comment, c.format,
c.timestamp, c.name, c.mail,
c.homepage, u.uid, u.name AS
registered_name, u.signature,
u.picture, u.data, c.thread, c.status
FROM {comments} c INNER JOIN {users} u
ON c.uid = u.uid WHERE c.nid = 141737
AND c.status = 0 ORDER BY c.thread
DESC
This returns all comments, ordered by the newest thread first:
03/
03.00/
02/
02.06/
02.05/
02.04/
02.03/
02.01/
02.00/
01/
The desired ordering in my case is this:
03/
03.00/
02/
02.00/
02.01/
02.02/
02.03/
02.04/
02.05/
02.06/
01/
Again just think of the Facebook wall and you get the idea.
Can anyone assist in enhancing the SQL query appropriately? In my case (but perhaps not in all cases) the thread depth is forcibly limited to 1 via a custom module.
One other note - in my case it only has to work under MySQL.
Well this query works, but again I'm a SQL noob so this probably isn't fully correct.
SELECT c.cid as cid, c.pid, c.nid,
c.subject, c.comment, c.format,
c.timestamp, c.name, c.mail,
c.homepage, u.uid, u.name AS
registered_name, u.signature,
u.picture, u.data, c.thread, c.status
FROM (SELECT c.cid as cid, c.pid,
c.nid, c.subject, c.comment, c.format,
c.timestamp, c.name, c.mail,
c.homepage, u.uid, u.name AS
registered_name, u.signature,
u.picture, u.data, c.thread, c.status
FROM comments c INNER JOIN users u
ON c.uid = u.uid WHERE c.nid = 141737
AND c.status = 0 ORDER BY
SUBSTRING(thread, 1, (LENGTH(thread) -
1))) c INNER JOIN users u ON c.uid =
u.uid WHERE c.nid = 141737 AND
c.status = 0 ORDER BY
SUBSTRING(thread, 1, 2) DESC
The idea is to first query with an ordering based on the full thread (02.05, etc) and then do another SELECT on just the first two characters of the thread field. Can I get a bit of help optimizing this or is it otherwise "correct"?
Related
I almost have my EF Core query working... This is the SQL getting produced (notice the Count(*):
SELECT [u].[Key], [u].[Url], [u].[CreatedBy], [u].[CreatedOn], COUNT(*) AS [Clicks]
FROM [URLs] AS [u]
LEFT JOIN [OwnerUrls] AS [o] ON [u].[Key] = [o].[ShortUrlKey]
LEFT JOIN [Clicks] AS [c] ON [u].[Key] = [c].[ShortUrlKey]
GROUP BY [u].[Key], [u].[Url], [u].[CreatedBy], [u].[CreatedOn]
What I need is (have Count look at a specific column/table)
SELECT [u].[Key], [u].[Url], [u].[CreatedBy], [u].[CreatedOn], COUNT(c.ID) AS [Clicks]
FROM [URLs] AS [u]
LEFT JOIN [OwnerUrls] AS [o] ON [u].[Key] = [o].[ShortUrlKey]
LEFT JOIN [Clicks] AS [c] ON [u].[Key] = [c].[ShortUrlKey]
GROUP BY [u].[Key], [u].[Url], [u].[CreatedBy], [u].[CreatedOn]
Here is the EF Query that I'm using...
query = (from u in db.URLs
join ou in db.OwnerUrls on u.Key equals ou.ShortUrlKey into urlOwners
from subSet in urlOwners.DefaultIfEmpty()
join c in db.Clicks on u.Key equals c.ShortUrlKey into urlClicks
from subClicks in urlClicks.DefaultIfEmpty()
group subClicks by new { u.Key, u.Url, u.CreatedBy, u.CreatedOn } into g
select new ShortURL()
{
Key = g.Key.Key,
Url = g.Key.Url,
CreatedBy = g.Key.CreatedBy,
CreatedOn = g.Key.CreatedOn,
Clicks = g.Count()
});
I've tried changing the g.Count() to g.Select(x=>x.Id).Count() and that just causes EF Core to barf and complain about client side evaluation vs server side evaluation etc..
I should mention that the reason I'm joining the first model (OwnerUrls) is to support a where clause that I didn't include here...
Thanks!
I'm not a EF developer, but have worked with SQL Server for a while now. In SQL Server i would use COUNT(DISTINCT c.ID) to eliminate any duplicates you might get from JOINS.
If duplicates are impossible due to the model the COUNT(*) shoud be sufficient.
Maybe this might help:
https://entityframeworkcore.com/knowledge-base/51892585/linq-select-distinct-count-performed-in-memory
I want in put two queries in one statement how can i do that in this state?
1
stmt = `SELECT Comments.*, Users.username,Users.avatar from Users
INNER JOIN Comments ON Comments.users_id =Users.users_id
WHERE Comments.post_id= 1`
2
`SELECT COUNT(*) comment FROM Comments WHERE Comments.post_id= 1`;
Cross join the 1st query to the 2nd:
SELECT c.*, u.username, u.avatar, t.counter
FROM Users u INNER JOIN Comments c
ON c.users_id = u.users_id
CROSS JOIN (SELECT COUNT(*) counter FROM Comments WHERE post_id = 1) t
WHERE c.post_id = 1
I don't know much about SQLite, but in SQL Server you can use ";" to use multiple queries.
Maybe it does work for SQLite.
You can use GROUP BY on comments table in a way:
'SELECT COUNT(Comments.<id>), Comments.*, Users.username,Users.avatar
from Users INNER JOIN Comments ON Comments.users_id =Users.users_id
WHERE Comments.post_id = 1 GROUP BY Comments.<id>';
*This syntax of GROUP BY clause follows PostgreSQL. You might need to tweak according to the syntax followed by sqlite.
I'm trying to write a query on two simple tables. Tables are simple, the query is not :)
Anyway...
Here is the database scheme :
and here is an overview of table content :
I'm trying to write a query that would list all assets in corresponding table, only if the are marked as "wanted" (meaning the boolean field asset_owned =0) and that are referenced for another owner as "owned".
This is what I have so far and it works :
SELECT
user.user_pseudo AS REQUESTER,
asset.asset_sku AS SKU,
asset.asset_name AS ASSET_NAME
FROM
asset
INNER JOIN user ON asset.id_user = user.id
WHERE
asset.asset_owned = 0
AND
asset.asset_sku IN (SELECT asset.asset_sku FROM asset WHERE asset.asset_owned = 1)
But, in the same query (if possible) I would like to get the owner name as well.
The first result of such a query on those table would be :
me,003,Test003,you.
I've tried inline SELECT and nested subqueries like :
SELECT
user.user_pseudo as ASKER,
asset.asset_sku as SKU,
asset.asset_name as NAME,
subquery1.user.user_pseudo as OWNER
FROM
asset
INNER JOIN user ON asset.id_user = user.id,
(SELECT user.user_pseudo.asset_asset_sku FROM asset INNER JOIN user ON asset.id_user = user.id WHERE asset.asset_owned = 1) subquery1
WHERE
asset.asset_owned = 0 AND
subquery1.asset.asset_sku IN (SELECT asset.asset_sku FROM asset INNER JOIN user ON asset.id_user = user.id WHERE asset.asset_owned=1)
but of course that does not work.
Thanks for any direction you could point me to.
happy new year
Mathias
So this was fun for me (I'm learning SQL, so this is good practice!) - I appreciate the very clear question.
Hopefully this works for you - I used two sub-queries (one each for 'owner' and 'requester') and then joined those on SKU and name. It works in SQLite with the small sample data shown above.
SELECT requester, subq1.SKU, subq1.name, owner
FROM
(SELECT pseudo AS requester, SKU, name
FROM asset, user
WHERE owned = 0
AND user.id = id_user) subq1,
(SELECT pseudo AS owner, SKU, name
FROM asset, user
WHERE owned = 1
AND asset.id_user = user.id) subq2
WHERE subq1.SKU = subq2.SKU
AND subq1.name = subq2.name;
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 am writing a report for the desktop support team in the company where I work. The report needs to produce a set of new starters within a specified time frame passed in from an ASP.NET application. Currently there is a one to many relationship between our Worker table and Contract table. We hire a lot of contractors and they sometimes come back after a number of months but are still treated like new starters as new machines need to be configured along with desk space.
A new contract is added for every pay review, job title change and new starter. We need to filter out all but the new starter. The newest contract that is added for job changes and pay reviews is always one day after the end date of the previous contract naturally. As I am only still a fresher in the grand scheme of things I am struggling with a set of functions I am trying to use to achieve my goal.
WHERE
(dbo.[Contract].StartDate BETWEEN #StartDateF AND #EndDateF) AND DATEDIFF(day, SELECT MAX(StartDate)FROM dbo.[Contract] WHERE dbo.[Contract].Worker_ID = w1.Worker_ID, SELECT MAX(EndDate)FROM dbo.[Contract] WHERE dbo.[Contract].Worker_ID = w1.Worker_ID)> 1
I basically want to find out in the instance an employee has more than one contract, regardless of leaving and coming back or pay review, if the current active contract is one day different to the previous contract. This should by my thinking give me all new starters only.
Trouble is I am still trying to get my head around when to use aggregate functions not in a select and when to apply the HAVING clause.
Any help would be appreciated to help me understand why my lack of understanding is causing this query/logic to fail.
Thanks
EDIT
Ok I am still bashing away at this solution and this is syntactically incorrect. In an attempt to remove some of the ambiguity here is the query, with an update;
Declare #StartDateF varchar(10)
Set #StartDateF = '2012-08-03'
Declare #EndDateF varchar(10)
Set #EndDateF = '2012-09-04'
SELECT w1.Worker_ID, w1.Title, w1.FirstName, w1.Surname,w1.Gender, w1.DateofBirth,
dbo.[Contract].StartDate, (select w2.surname + ',' + w2.firstname from worker w2 WITH (NOLOCK) where w2.worker_ID = w1.manager)as Manager, dbo.Grade.GradeDescription AS JobTitle, dbo.Grade.Discipline,
CASE WHEN dbo.[Contract].ContractType_ID = 1 OR dbo.[Contract].ContractType_ID = 2 OR dbo.[Contract].ContractType_ID = 5 OR dbo.[Contract].ContractType_ID = 6
THEN 'Staff' ELSE 'Contractor' END AS ContractType
FROM dbo.Worker w1 WITH (NOLOCK) inner join
dbo.[Contract] WITH (NOLOCK) ON dbo.[Contract].Worker_ID = w1.Worker_ID inner join
dbo.Grade WITH (NOLOCK) ON dbo.Grade.Grade_ID = dbo.[Contract].Grade_ID
WHERE
(dbo.[Contract].StartDate BETWEEN #StartDateF AND #EndDateF AND EndDate IS NULL)
group by
w1.Worker_ID, w1.Title, w1.FirstName, w1.Surname,w1.Gender, w1.DateofBirth,
dbo.[Contract].StartDate, manager, dbo.Grade.Discipline,dbo.Grade.GradeDescription, dbo.[Contract].ContractType_ID
Having DATEDIFF(day, SELECT MAX(StartDate)FROM dbo.[Contract] WHERE dbo.[Contract].Worker_ID = w1.Worker_ID, SELECT MAX(EndDate)FROM dbo.[Contract] WHERE dbo.[Contract].Worker_ID = w1.Worker_ID)
I have added the group by and the having clause but now I am getting the following errors
Msg 156, Level 15, State 1, Line 24
Incorrect syntax near the keyword 'SELECT'.
Msg 102, Level 15, State 1, Line 24
Incorrect syntax near ','.
Msg 102, Level 15, State 1, Line 24
Incorrect syntax near ')'.
These all relate the the functions in the having clause no doubt you can see. But I cannot understand what is wrong with this query and this is mainly the question. I need to understand the SQL functions enough so that I can implement th correct solution.
I have followed up the DATEDIFF() function here http://msdn.microsoft.com/en-us/library/ms189794.aspx
I can see that using functions within this function is acceptable according to the MS documentation.
EDIT
Commenting out the Having clause gives me the result set I expect. It is showing people with changes to contracts(pay rise) but this is information that no one should be seeing, these are now the only records that need filtering out
EDIT
I have made some improvements and overcome the error messages now, but I am still getting people where pay rises have occured. Here is the amended query from the group by
group by
w1.Worker_ID, w1.Title, w1.FirstName, w1.Surname,w1.Gender, w1.DateofBirth,
dbo.[Contract].StartDate, manager, dbo.Grade.Discipline,dbo.Grade.GradeDescription, dbo.[Contract].ContractType_ID, w1.Worker_ID
Having
(((dbo.[Contract].StartDate BETWEEN #StartDateF AND #EndDateF)
AND COUNT(dbo.[Contract].Worker_ID) = 1)
OR
((dbo.[Contract].StartDate BETWEEN #StartDateF AND #EndDateF)
AND DATEDIFF(day, (SELECT MAX(EndDate)FROM dbo.[Contract] WHERE dbo.[Contract].Worker_ID = w1.Worker_ID), (SELECT MAX(StartDate)FROM dbo.[Contract] WHERE dbo.[Contract].Worker_ID = w1.Worker_ID))>1))
To get workers with more than one contract, you would use:
select c.workerID
from Contract c
group by c.workerID
having count(distinct contractID) > 1
It sounds, though, like you only want to count everything but the new start ones. You can do this with something like:
select w.workerID
from Contract c
where c.ContractType = 'New'
group by w.workerID
having count(distinct contractID) > 1
Because you didn't provide the details of what the tables look like, what sample input data looks like, and the results you want to achieve, this is about the best that can be done.
WHERE ( (dbo.[Contract].StartDate BETWEEN #StartDateF AND #EndDateF)AND dbo.[Contract].Worker_ID
IN (select worker_id from dbo.[Contract]
group by worker_id
having count(worker_id) = 1))
OR
((dbo.[Contract].StartDate BETWEEN #StartDateF AND #EndDateF)
AND DATEDIFF(day, (SELECT MAX(EndDate)FROM dbo.[Contract] WHERE dbo.[Contract].Worker_ID = w1.Worker_ID), (SELECT MAX(StartDate)FROM dbo.[Contract] WHERE dbo.[Contract].Worker_ID = w1.Worker_ID))>1
AND dbo.[Contract].Worker_ID = w1.Worker_ID )
Now works for me :)