I need nhiberante query (not HQL) equivalent following SQL:
SELECT ur.*
FROM (SELECT MAX(requestTime) rt, macAddress ma
FROM UpdateRequests
GROUP BY macAddress) mur
JOIN dbo.UpdateRequests ur
ON mur.ma = ur.macAddress AND mur.rt = ur.requestTime
I had no luck with other similar examples on stackoverflow.
Having UpdateRequest mapping, it seems that is not possible with Query API, how about QueryOver?
Finally one Guru suggested me to change SQL query without changing execution plan:
SELECT ur.*
FROM [dbo].[UpdateRequests] AS ur
WHERE ur.[RequestTime] = (SELECT MAX(mur.[RequestTime])
FROM [dbo].[UpdateRequests] mur
WHERE mur.[MacAddress] = ur.[MacAddress])
So in code it transforms into:
session
.Query<UpdateRequest>()
.Where(ur => ur.RequestTime == session.Query<UpdateRequest>()
.Where(mur => mur.MacAddress == ur.MacAddress)
.Max(mur => mur.RequestTime))
.ToList();
And this is exactly what i need.
Is it possible in NHibernate to inner join objects during query time with Criteria?
I would like to accomplish something like this:
SELECT p
FROM Person p
INNER JOIN Section s
ON p.sid = s.id
AND p.companyid = s.companyid
The join isn't in the mapping (and can't be there).
Is there something like the following syntax?
var list = session.CreateCriteria(typeof(Person), "p")
.CreateCriteria(typeof(Section), "s")
.Add(Expression.EqProperty("p.SectionId", "s.Id"))
.Add(Expression.EqProperty("p.CompanyId", "s.CompanyId"))
.List();
Is this at all possible? I can't use detachedcriteria here because I have two properties I'm using for joining.
OK, I figured it out, you can use a detachedquery.
I used the following:
var list = session.CreateCriteria(typeof(Person), "p")
.Add(Subqueries.PropertyIn("SectionId", typeof(Section), "s")
.SetProjection(Projections.Property("Id"))
.Add(Expression.EqProperty("s.Id", "p.SectionId"))
.Add(Expression.EqProperty("s.CompanyId", "p.CompanyId"))
)).List();
Which generates an in query which does the same as the inner join.
If you have any "nicer" alternatives, please feel free to share.
I want to write a join statement in LINQ using the dbgeography's "Intersects" method (I am using EF June 2011 CTP). The problem is if I write something like this:
var joinQuery = from spQ in spatialTableQuery
join mnQ in MainQuery
on spQ.Polygon.Intersects(mnQ.PointGeography) equals 1
I get the following error:
The name 'mnQ' is not in scope on the left side of 'equals'. Consider
swapping the expressions on either side of 'equals'.
In SQL I have written a similar query as below so I know SQL suppports it:
SELECT * FROM Address a
INNER JOIN SPATIALTABLE b
WITH(INDEX(geog_sidx))
ON b.geom.STIntersects(a.PointGeography) = 1
Try something like this:
var joinQuery =
from spQ in spatialTableQuery
from mnQ in MainQuery
where spQ.Polygon.Intersects(mnQ.PointGeography) = 1
I have a question about joins in NHIBERNATE. We had an issue with our sql query that was generated but nhibernate. Our db developer optimized the raw sql so it works as we need, but we need to change the nhibernate code to make generated sql look like optimized.
the part of the original part of the query is:
FROM PERSON_VISIT this_
inner join PERSON_Basic per2_
on this_.PERSON_ID = per2_.PERSON_ID
left outer join PERSONC_QUESTIONS perint10_
on per2_.PERSON_ID = perint10_.PERSON_ID
left outer join TELEPHONE_QUESTIONS intaudit13_
on perint10_.PP_QUESTIONS_ID = intaudit13_.PP_QUESTIONS_ID
inner join C_QUESTIONS intdef14_
on perint10_.QUESTION_ID = intdef14_.QUESTION_ID
and perint10_.QUESTIONS_CODE = intdef14_.QUESTIONS_CODE
and perint10_.QUESTION_ID = intdef14_.QUESTION_ID
The optimized one is :
FROM PERSON_VISIT this_
inner join PERSON_Basic per2_
on this_.PERSON_ID = per2_.PERSON_ID
left outer join PERSONC_QUESTIONS perint10_
on per2_.PERSON_ID = perint10_.PERSON_ID
left outer join TELEPHONE_QUESTIONS intaudit13_
on perint10_.PP_QUESTIONS_ID = intaudit13_.PP_QUESTIONS_ID
left outer join C_QUESTIONS intdef14_
on perint10_.QUESTION_ID = intdef14_.QUESTION_ID
and perint10_.QUESTIONS_CODE = intdef14_.QUESTIONS_CODE
and perint10_.QUESTION_ID = intdef14_.QUESTION_ID
and intdef14_.DISCIPLINE_CODE = this_.DISCIPLINE_CODE
To change query from inner join to left outer join is easy, i changed only one line of code:
.CreateAlias("PersonInt.QuestionEntity", "IntDef", JoinType.LeftOuterJoin)
But how I can add
and intdef14_.DISCIPLINE_CODE = this_.DISCIPLINE_CODE
using nhibernate code?
There is an option to add reference from PERSON_VISIT definition to C_QUESTIONS, but the problem is that
PERSON_VISIT is used everywhere and I don't want this change to possibly break other queries, I just wnat to add only one line of code to add, how I can do that? Is there any way to have access to the raw join to change it? Or some other way to add this
and intdef14_.DISCIPLINE_CODE = this_.DISCIPLINE_CODE
To the query?
I know that somebody will say that we can add a restriction to the query through criteria.Add, but it is not an option cause db developer optimized our query taking this restriction from WHERE clause to the join.
How I can do that quickly without changing the models definitions? Just changing only this one query without changing the whole model?
It is possible using HQL and the Criteria API's.
This question gives you the answer: Adding conditionals to outer joins with nhibernate
Something like this may solve your issue.
.CreateAlias("PersonInt.QuestionEntity", "IntDef", JoinType.LeftOuterJoin,
Restrictions.EqProperty("DISCIPLINE_CODE", "IntDef.DISCIPLINE_CODE"))
Thanks for answers. We use 2.0 version of NHibernate in our project so we didn't have a chance to use new methods of .CreateAlias with restrictions.
I have fixed an issue using Interceptors:
public class SqlInterceptor : EmptyInterceptor, IInterceptor
{
SqlString IInterceptor.OnPrepareStatement(SqlString sql)
{
//manipulating with the sql
return sql;
}
}
than
var factory = Session.SessionFactory;
var session = factory.OpenSession(new SqlInterceptor());
And use my query without a change.
We are working on a spring mvc project with hibernate.
When we execute the following code:
try {
HibernateTemplate ht = new HibernateTemplate(sf);
List<Route> r = ht.findByNamedParam("select r from Route r inner join r.carPoolers as carPooler where (( r.owner.id = :userid ) or ( carPooler.user.id = :userid )) AND r.id =:routeID", new String[]{"userid", "routeID"} , new Object[]{ u.getId() , id});
if (r.size() == 1) {
return r.get(0);
} else {
return null;
}
} catch (DataAccessException ex) {
LogFactory.getLog(RouteRepository.class).fatal(ex);
return null;
}
this is the result:
SELECT ROUTE0_.ID AS ID4_, ROUTE0_.ARRIVALTIME AS ARRIVALT2_4_,
ROUTE0_.CAR_ID AS CAR13_4_, ROUTE0_.DATE AS DATE4_,
ROUTE0_.DAYOFWEEK AS DAYOFWEEK4_, ROUTE0_.DEPARTURETIME AS
DEPARTUR5_4_, ROUTE0_.ENDDATE AS ENDDATE4_, ROUTE0_.MESSAGEID
AS MESSAGEID4_, ROUTE0_.OPENSEATS AS OPENSEATS4_,
ROUTE0_.OWNER_ID AS OWNER14_4_, ROUTE0_.ROUTECACHE_ID AS
ROUTECACHE11_4_, ROUTE0_.ROUTEOPTIMIZED AS ROUTEOPT9_4_,
ROUTE0_.START_ID AS START12_4_, ROUTE0_.STOP_ID AS STOP10_4_
FROM ROUTE ROUTE0_ INNER JOIN CARPOOLER CARPOOLERS1_ ON
ROUTE0_.ID=CARPOOLERS1_.ROUTEID
WHERE (route0_.owner_id=? or carpoolers1_.user_id=?) and route0_.id=?
SELECT CAR0_.ID AS ID5_3_, CAR0_.BRAND_ID AS BRAND8_5_3_, CAR0_.CARNAME
AS CARNAME5_3_, CAR0_.CARTYPE AS CARTYPE5_3_, CAR0_.IMAGEURL AS
IMAGEURL5_3_, CAR0_.PRICEKM AS PRICEKM5_3_, CAR0_.SEATS AS
SEATS5_3_, CAR0_.USER_ID AS USER7_5_3_, BRAND1_.ID AS ID6_0_,
BRAND1_.BRANDNAME AS BRANDNAME6_0_, USER2_.ID AS ID0_1_,
USER2_.EMAIL AS EMAIL0_1_, USER2_.FACEBOOKID AS FACEBOOKID0_1_,
USER2_.FIRSTNAME AS FIRSTNAME0_1_, USER2_.GENDER AS GENDER0_1_,
USER2_.IMAGEURL AS IMAGEURL0_1_, USER2_.LANGUAGE_ID AS
LANGUAGE12_0_1_, USER2_.LASTNAME AS LASTNAME0_1_,
USER2_.MOBILEPHONE AS MOBILEPH8_0_1_, USER2_.PASSWORD AS
PASSWORD0_1_, USER2_.SMOKER AS SMOKER0_1_, USER2_.TELEPHONE AS
TELEPHONE0_1_, LANGUAGE3_.ID AS ID9_2_, LANGUAGE3_.LANGUAGE AS
LANGUAGE9_2_, LANGUAGE3_.LANGUAGECODE AS LANGUAGE3_9_2_
FROM CAR CAR0_ LEFT OUTER JOIN BRAND BRAND1_ ON
CAR0_.BRAND_ID=BRAND1_.ID LEFT OUTER JOIN USER USER2_ ON
CAR0_.USER_ID=USER2_.ID LEFT OUTER JOIN LANGUAGE LANGUAGE3_ ON
USER2_.LANGUAGE_ID=LANGUAGE3_.ID
WHERE car0_.id=?
SELECT USER0_.ID AS ID0_1_, USER0_.EMAIL AS EMAIL0_1_,
USER0_.FACEBOOKID AS FACEBOOKID0_1_, USER0_.FIRSTNAME AS
FIRSTNAME0_1_, USER0_.GENDER AS GENDER0_1_, USER0_.IMAGEURL AS
IMAGEURL0_1_, USER0_.LANGUAGE_ID AS LANGUAGE12_0_1_,
USER0_.LASTNAME AS LASTNAME0_1_, USER0_.MOBILEPHONE AS
MOBILEPH8_0_1_, USER0_.PASSWORD AS PASSWORD0_1_, USER0_.SMOKER
AS SMOKER0_1_, USER0_.TELEPHONE AS TELEPHONE0_1_, LANGUAGE1_.ID
AS ID9_0_, LANGUAGE1_.LANGUAGE AS LANGUAGE9_0_,
LANGUAGE1_.LANGUAGECODE AS LANGUAGE3_9_0_
FROM USER USER0_ LEFT OUTER JOIN LANGUAGE LANGUAGE1_ ON
USER0_.LANGUAGE_ID=LANGUAGE1_.ID
WHERE user0_.id=?
SELECT ROUTECACHE0_.ID AS ID7_2_, ROUTECACHE0_.AANTALM AS AANTALM7_2_,
ROUTECACHE0_.AANTALMIN AS AANTALMIN7_2_, ROUTECACHE0_.ACTIVE AS
ACTIVE7_2_, ROUTECACHE0_.JSON AS JSON7_2_,
ROUTECACHE0_.LOCATIONS AS LOCATIONS7_2_,
ROUTECACHE0_.LOCATIONSOPTIMIZED AS LOCATION7_7_2_,
ROUTECACHE0_.ROUTEOPTIMIZED AS ROUTEOPT8_7_2_,
ROUTECACHE0_.START_ID AS START10_7_2_, ROUTECACHE0_.STOP_ID AS
STOP9_7_2_, LOCATION1_.ID AS ID2_0_, LOCATION1_.LANG AS
LANG2_0_, LOCATION1_.LAT AS LAT2_0_, LOCATION1_.NUMBER AS
NUMBER2_0_, LOCATION1_.STREET AS STREET2_0_, LOCATION1_.ZIPCODE
AS ZIPCODE2_0_, LOCATION2_.ID AS ID2_1_, LOCATION2_.LANG AS
LANG2_1_, LOCATION2_.LAT AS LAT2_1_, LOCATION2_.NUMBER AS
NUMBER2_1_, LOCATION2_.STREET AS STREET2_1_, LOCATION2_.ZIPCODE
AS ZIPCODE2_1_
FROM ROUTECACHE ROUTECACHE0_ LEFT OUTER JOIN LOCATION LOCATION1_ ON
ROUTECACHE0_.START_ID=LOCATION1_.ID LEFT OUTER JOIN LOCATION
LOCATION2_ ON ROUTECACHE0_.STOP_ID=LOCATION2_.ID
WHERE routecache0_.id=?
SELECT ROUTECACHE0_.ROUTECACHESPUNTENTUSSEN_ID AS ROUTECAC1_1_,
ROUTECACHE0_.ROUTECACHETUSSENPUNTEN_ID AS ROUTECAC2_1_,
LOCATION1_.ID AS ID2_0_, LOCATION1_.LANG AS LANG2_0_,
LOCATION1_.LAT AS LAT2_0_, LOCATION1_.NUMBER AS NUMBER2_0_,
LOCATION1_.STREET AS STREET2_0_, LOCATION1_.ZIPCODE AS
ZIPCODE2_0_
FROM ROUTECACHE_LOCATION_PUNTEN ROUTECACHE0_ LEFT OUTER JOIN LOCATION
LOCATION1_ ON
ROUTECACHE0_.ROUTECACHETUSSENPUNTEN_ID=LOCATION1_.ID
WHERE routecache0_.routecachesPuntenTussen_id=?
SELECT CARPOOLERS0_.ROUTEID AS ROUTEID5_, CARPOOLERS0_.ID AS ID5_,
CARPOOLERS0_.ID AS ID3_4_, CARPOOLERS0_.APPROVED AS
APPROVED3_4_, CARPOOLERS0_.ONETIME AS ONETIME3_4_,
CARPOOLERS0_.ROUTEID AS ROUTEID3_4_, CARPOOLERS0_.START_ID AS
START5_3_4_, CARPOOLERS0_.STOP_ID AS STOP7_3_4_,
CARPOOLERS0_.USER_ID AS USER6_3_4_, LOCATION1_.ID AS ID2_0_,
LOCATION1_.LANG AS LANG2_0_, LOCATION1_.LAT AS LAT2_0_,
LOCATION1_.NUMBER AS NUMBER2_0_, LOCATION1_.STREET AS
STREET2_0_, LOCATION1_.ZIPCODE AS ZIPCODE2_0_, LOCATION2_.ID AS
ID2_1_, LOCATION2_.LANG AS LANG2_1_, LOCATION2_.LAT AS LAT2_1_,
LOCATION2_.NUMBER AS NUMBER2_1_, LOCATION2_.STREET AS
STREET2_1_, LOCATION2_.ZIPCODE AS ZIPCODE2_1_, USER3_.ID AS
ID0_2_, USER3_.EMAIL AS EMAIL0_2_, USER3_.FACEBOOKID AS
FACEBOOKID0_2_, USER3_.FIRSTNAME AS FIRSTNAME0_2_,
USER3_.GENDER AS GENDER0_2_, USER3_.IMAGEURL AS IMAGEURL0_2_,
USER3_.LANGUAGE_ID AS LANGUAGE12_0_2_, USER3_.LASTNAME AS
LASTNAME0_2_, USER3_.MOBILEPHONE AS MOBILEPH8_0_2_,
USER3_.PASSWORD AS PASSWORD0_2_, USER3_.SMOKER AS SMOKER0_2_,
USER3_.TELEPHONE AS TELEPHONE0_2_, LANGUAGE4_.ID AS ID9_3_,
LANGUAGE4_.LANGUAGE AS LANGUAGE9_3_, LANGUAGE4_.LANGUAGECODE AS
LANGUAGE3_9_3_
FROM CARPOOLER CARPOOLERS0_ LEFT OUTER JOIN LOCATION LOCATION1_ ON
CARPOOLERS0_.START_ID=LOCATION1_.ID LEFT OUTER JOIN LOCATION
LOCATION2_ ON CARPOOLERS0_.STOP_ID=LOCATION2_.ID LEFT OUTER
JOIN USER USER3_ ON CARPOOLERS0_.USER_ID=USER3_.ID LEFT OUTER
JOIN LANGUAGE LANGUAGE4_ ON USER3_.LANGUAGE_ID=LANGUAGE4_.ID
WHERE carpoolers0_.RouteId=?
Problem:
This takes minimum 460ms.
We only need the first query for our results.
,
ty in advance
You probably have so many queries because some relationships are eager loaded. Note that by default all OneToOne and ManyToOne relationships are eager loaded. This means that if a route has a car, which has a user, which has a language, etc., Hibernate will load all these referenced entities each time it loads a route.
Make them lazy loaded instead, and tune your queries to fetch only the entities you need.
I guess returned object is passed to some automatic serializer (you use #ResponseBody, yes?) that tries to serialize the whole graph of accessible objects and therefore triggers lazy loading of related objects which you don't need.
If so, you can create a DTO that contains only necessary fields, populate it from the loaded entity and return that DTO instead of entity.
Alternative approach would be to configure serializer to make it serialize only necessary fields, but it can be more complex.
See this for how to get only 1 result: How do you do a limit query in HQL?.
Have you configured indexes on your tables?