NHibernate Left Outer Join - nhibernate

I'm looking to create a Left outer join Nhibernate query with multiple on statements akin to this:
SELECT
*
FROM [Database].[dbo].[Posts] p
LEFT JOIN
[Database].[dbo].[PostInteractions] i
ON
p.PostId = i.PostID_TargetPost And i.UserID_ActingUser = 202
I've been fooling around with the critera and aliases, but I haven't had any luck figuring out how do to this. Any suggestions?

I actually figured it out. You need to do a check for null
.CreateCriteria("Interactions", "i", NHibernate.SqlCommand.JoinType.LeftOuterJoin)
.Add(Expression.Or(Expression.Eq("i.ActingUser", user), Expression.IsNull("i.ActingUser")))
this creates a left join on targetpost id and then eliminates all non null/non user interactions.

I spent a long while checking all kinds of posts that did not do what I needed and your post is the closest to what I was looking for.
From my tests (with nHibernate 3) your query is not correct. Actually your criteria looks more like this in SQL :
SELECT *
FROM [Posts] p
LEFT JOIN [PostInteractions] i
ON p.PostId = i.PostID_TargetPost
WHERE (i.UserID_ActingUser = 202 OR i.UserID_ActingUser IS NULL)
Which returns posts/interactions only when the interaction's ActingUser is 202 or that no interaction exists for the post.
After lot more tests I finally figured it out...
Try this (vb.net) :
session.CreateCriteria(Of Posts)("p") _
.CreateCriteria("Interactions", "i", _
NHibernate.SqlCommand.JoinType.LeftOuterJoin, _
Expression.Eq("i.ActingUser", user))
There's an overload to the CreateCriteria function using a "withClause". That worked perferctly for me and I believe that it's what you're looking for too.
I know the topic's pretty old but if it can help anyone else....
Also, for great examples on nHibernate queries (it was a huge help for me): http://ayende.com/blog/4023/nhibernate-queries-examples
Have fun!

Related

Converting subquery to join assistance

I am my subquery is severely slowing my full query down in MySQL. I'm in the process of converting the original query to work on MySQL as I'm moving away from SQL Server where it has worked wonderfully. MySQL on the other hand isnt too happy. Was wondering if anyone could assist in helping me with a conversion solution to a join as I'm not well versed in joins quite yet. Thanks!
select a.crm_ticket_details_detail,
crm_ticket_created_date,
crm_ticket_id,
crm_ticket_customer_id,
c.crm_assigned_user
from php_crm.crm_ticket,
php_crm.crm_ticket_details a,
php_crm.crm_assigned c
where crm_ticket_resolved_date is null
and crm_ticket_id = a.crm_ticket_details_ticket_id
and a.crm_ticket_details_type = 'issue'
and c.crm_assigned_ticket_id = crm_ticket_id
and c.crm_assigned_id = (select max(d.crm_assigned_id)
from php_crm.crm_assigned d
where d.crm_assigned_ticket_id = crm_ticket_id)
SELECT
details.crm_ticket_details_detail,
CT.crm_ticket_created_date,
CT.crm_ticket_id,
CT.crm_ticket_customer_id,
ASSIGNED.crm_assigned_user
FROM
php_crm.crm_ticket CT (NONAME)
INNER JOIN php_crm.crm_ticket_details DETAILS -- (A)
ON CT.crm_ticket_id = DETAILS.crm_ticket_details_ticket_id
INNER JOIN php_crm.crm_assigned ASSIGNED -- (C)
ON CT.crm_ticket_id = ASSIGNED.crm_assigned_ticket_id
WHERE
crm_ticket_resolved_date IS NULL
AND DETAILS.crm_ticket_details_type = 'issue'
AND
AND ASSIGNED.crm_assigned_id = (SELECT
max(d.crm_assigned_id)
FROM
php_crm.crm_assigned d
WHERE
d.crm_assigned_ticket_id = crm_ticket_id)
I believe that's what you're looking for. I can't speak to whether it will actually improve performance, although it will certainly make it easier to understand. I'm not sure the old style of joins is actually less efficient; just harder to read / easier to make product joins with.
That said, if there are other common keys between the three tables that are being indirectly neutralized in other parts of the logic then that could have a performance impact.
(EDIT: Actually not sure if this was what you're looking for, reread your question and you seem focused on the subquery... I don't see any problems jumping out with that, would need more details to address that.)

Right Join in Doctrine2 for Symfony2

I have the following working MySQL query:
SELECT *
FROM bogenantworten a
RIGHT JOIN
bogenfragen f ON f.id = a.bogenfragen_id
AND a.personen_id = 3,
BogenTyp t,
BogenFragenGruppe g
WHERE
t.id = f.fragentyp_id AND
g.id = f.fragengruppen_id AND
t.id = 1
ORDER BY f.sortierung ASC
Now I need this in Doctrine2 DQL or QueryBuilder. I already learned that D2 is forcing me to think in objects, but I couldn't find any advice how to tag my entities to make this work.
So I'd like to either have the above MySQL query working in my Symfony2 app or some help how to annotate my entities right so I have a working right join connection between BogenAntworten and BogenFragen (the 3 and the 1 are parameters, just so you know). I already set the OneToMany and ManyToOne annotations for all my entities, but I need something to make a right/left join working.
If you want to help me with my entity design:
I have persons (table Person) who answers (table BogenAntworten) questions (table BogenFragen), and when I show the list of questions I either get the last answer from that question (need UPDATE when saving) or there is none and I have to create it (INSERT when saving). Questions also are in one of many types (table BogenTyp) and are in one of many groups (table BogenFragenGruppe)
Any Ideas?
OK, found it out myself again. The QueryBuilder of Doctrine2 supports a leftJoin (which is identical to the RIGHT JOIN if you switch the two tables). For those need some code, here is the above SQL statement build with QueryBuilder:
$query = $em->createQueryBuilder()
->select(array('f.id', 'f.frage', 'f.sortierung', 'a.antwort', 'g.name'))
->from('MySuperBundle:BogenFragen', 'f')
->leftJoin('f.bogenantworten', 'a', 'WITH', 'a.personen = :pid')
->from('MySuperBundle:BogenTyp', 't')
->from('MySuperBundle:BogenFragenGruppe', 'g')
->where('t.id = :tid')
->andWhere('t.id = f.bogentypen')
->andWhere('g.id = f.bogenfragengruppe')
->orderBy('f.sortierung', 'ASC')
->setParameter('tid', 1)
->setParameter('pid', 3)
->getQuery();
(The parameters are actually dynamic, but for easier reading I used the numbers of the original SQL statement)

SQL to query drupal nodes with multiple taxonomies

Good morning all.
I've read some of the suggested question before posting this but seems like no one has my same issue (probably and inidicator of how bad I am in Drupal and coding in general)
I need to write a query that returns all the nodes with TWO SPECIFIC taxonomies associated to it (of which I know the IDs), but it seems I don't know the right syntax cause I just manage to get it work with ONE term id.
Here's what I have so far (and works)
SELECT * FROM node
INNER JOIN term_node AS tn ON node.vid = tn.vid
LEFT JOIN content_type_extra_content AS xc ON node.vid = xc.vid
WHERE tn.tid IN (SELECT th.tid FROM term_hierarchy AS th WHERE th.tid = '146')
That '146' is the id of the first taxonomy term I need to check (call it "shoes")
Now I have to check that the node has also the taxonomy id '223' (call it "season")
I've tried different solutions with no avail.
I'm pretty sure the solution is under my nose but at the moment I can't wrap my head around it.
Please note that the taxonomies are in different vocaboularies and they are at level-0
Thanks in advance for any help
If I understand you correctly, you want the nodes which have 2 specific terms (shoes and season), then try something like this:
SELECT * FROM node
INNER JOIN term_node AS tn ON node.vid = tn.vid
LEFT JOIN content_type_extra_content AS xc ON node.vid = xc.vid
WHERE tn.tid IN ('146','223')
GROUP BY node.vid
HAVING count(*) = 2

relationships produce duplicate records on query, DISTINCT does not work, any other solutions available?

I am new to this portal. I have a very simple problem to be solved. It is related to the ANSI SQL. I am writing a reports using BIRT and I am fetching the data from several tables. I understand how the SQL joins work but maybe not fully. I researched google for hours and I could not find relevant answer.
My problem is that one of the relationships in the code produce a duplicate result (the same row is copied - duplicated). I was so determined to solve it I used every type of join available. Some of this SQL was produced already. I shall post my code below. I know that one of the solutions to my problem is use of the 'DISTINCT' keyword. I have used it and it does not solve my problem.
Can anyone propose any solution to that?
Sample code:
SELECT DISTINCT
partmaster.partdesc,
partmaster.uom,
traders.name AS tradername,
worksorders.id AS worksorderno,
worksorders.partid,
worksorders.quantity,
worksorders.duedate,
worksorders.traderid,
worksorders.orderid,
routingoperations.partid,
routingoperations.methodid,
routingoperations.operationnumber,
routingoperations.workcentreid,
routingoperations.settime,
routingoperations.runtime,
routingoperations.perquantity,
routingoperations.description,
routingoperations.alternativeoperation,
routingoperations.alternativeoperationpreference,
machines.macdesc,
machines.msection,
allpartmaster.partnum,
allpartmaster.nbq,
allpartmaster.partdesc,
routingoperationtools.toolid,
tools.tooldesc,
CAST (emediadetails.data as VARCHAR(MAX)) AS cplandata
FROM worksorders
INNER JOIN partmaster ON worksorders.partid = partmaster.partnum
INNER JOIN traders traders ON worksorders.traderid = traders.id
INNER JOIN routingoperations routingoperations ON worksorders.partid = routingoperations.partid
AND worksorders.routingmethod = routingoperations.methodid
INNER JOIN allpartmaster allpartmaster ON routingoperations.partid = allpartmaster.partnum
LEFT OUTER JOIN machines machines ON routingoperations.workcentreid = machines.macid
LEFT OUTER JOIN routingoperationtools routingoperationtools ON routingoperationtools.partid = routingoperations.partid
AND routingoperationtools.routingmethod = routingoperations.methodid
AND routingoperationtools.operationnumber = routingoperations.operationnumber
LEFT OUTER JOIN tools tools ON tools.toolid = routingoperationtools.toolid
LEFT OUTER JOIN emediadetails ON emediadetails.keyvalue1 = worksorders.id
AND emediadetails.keyvalue2 = routingoperations.operationnumber
AND emediadetails.emediaid = 'worksorderoperation'
I do not have too much of the test data but I know that one row is copied twice as the result of the query below even tho I used DISTINCT keyword. I know that my problem is rather specific and not general but the solution that someone will propose may help others with the similar problem.
I can't solve your problem for you without some test data, but I have some helpful hints.
In principle, you should be really careful with DISTINCT - its a great way of hiding bugs in your query. Only use DISTINCT if you are confident that the underlying data contains legitimate duplicates. If your joins are wrong, and you're getting a cartesian product, you can remove the duplicates from the results with DISTINCT - but that doesn't stop the cartesian product being generated. You'll get very poor performance, and possibly incorrect data.
Secondly, I am pretty sure that DISTINCT works properly - you are almost certainly not getting duplicates, but it may be hard to spot the difference between two rows. Leading or trailing spaces in text columns, for instance could be to blame.
Finally, to work through this problem, I'd recommend building the query up join by join, and seeing where you get the duplicate - that's the join that's to blame.
So, start with:
SELECT
traders.name AS tradername,
worksorders.id AS worksorderno,
worksorders.partid,
worksorders.quantity,
worksorders.duedate,
worksorders.traderid,
worksorders.orderid
FROM worksorders
INNER JOIN traders traders ON
worksorders.traderid = traders.id
and build up to the next join.
Are you sure the results are exact duplicates? Makes sure there isn't one column that actually has a different value.

Inconsistent results between NHibernate Query and intended results

I have the following query in HQL :
public IEnumerable<Player> PlayersNotInTeam(Team team)
{
return Session.CreateQuery("from Player p where p.Sex = :teamSex and p.Visible and p.Id not in (select pit.Player from PlayerInTeam as pit join pit.Roster as roster join roster.Team as team where team = :teamId)")
.SetParameter("teamId", team.Id)
.SetParameter("teamSex", team.Sex)
.Enumerable<Player>();
}
When I run this query with NHibernate, it will return 2 rows.
If I run the SQL script generated by NH in my database browser (SQLite Explorer):
select player0_.Id as Id26_, player0_.Sex as Sex26_, player0_.FirstName as FirstName26_, player0_.LastName as LastName26_, player0_.DefaultNumber as DefaultN5_26_, player0_.Visible as Visible26_, player0_.DefaultPosition_id as DefaultP7_26_
from Players player0_
where player0_.Sex='Male'
and player0_.Visible=1
and (player0_.Id not in
(select playerinte1_.Player_id
from "PlayerInTeam" playerinte1_
inner join "Roster" roster2_ on playerinte1_.Roster_id=roster2_.Id
inner join Teams team3_ on roster2_.Team_id=team3_.Id,
Players player4_
where playerinte1_.Player_id=player4_.Id
and team3_.Id=2));
I have 3 rows, which is what I should have.
Why are my results different?
Thanks in advance
Mike
I have noticed that sometimes the logged SQL is not exactly the same as the one being really used against the database. The last time I had this issue, it was a problem with trimming the Id value, e.g., where the generated SQL has something like and team3_.Id=2, the SQL being used was actually and team3_.Id='2 ' (or perhaps, player_0.Sex='Male '), which would always fail.
I would suggest you try this HQL:
string hql = #"from Player p where p.Sex = 'Male'
and p.Visible and p.Id not in
(select pit.Player from PlayerInTeam as pit join pit.Roster as roster join roster.Team as team where team = 2)";
return Session.CreateQuery(hql).Enumerable<Player>();
If that works, you need to check if your values have spare whitespaces in them.
I've changed my query like this:
return Session.CreateQuery("from Player p where p.Sex = :teamSex and p.Visible and not exists (from PlayerInTeam pit where pit.Player = p and pit.Roster.Team = :teamId)")
.SetParameter("teamId", team.Id)
.SetParameter("teamSex", team.Sex)
.Enumerable<Player>();
And it now works. I had the idea to use "not exists" after I changed my mappings to try to use LINQ, which gave me the hint.
If you ask why I don't keep LINQ, that's because currently I hide the relationships between my entities as private fields, to force the users of the entities to use the helper functions which associate them. But the wrong thing is that in most cases, that forbids me to use LINQ in my repositories.
But I'm wondering if this wouldn't be better to "un-hide" my relationships and expose them as public properties, but keep my helper functions. This would allow me to use LINQ in my queries.
What do you do in your apps using NH?
Do you think this would be an acceptable trade-off to maintain easy mappings and queries (with the use of LINQ), but with the cost of some potential misuses of the entities if the user doesn't use the helper functions which keep the relationships?