Is there an equivalent to the native sql !=-operator for Spring Data JPA #Query-Annotation using OpenJPA? So i thought it would work somewhat like this:
#Query("select a from TableA a, TableB b where a.property != b.property")
but it doesn't, or lets say at least my ide (intellij) shows me that it does not know how to work with '!='.
The (as i thought) corresponding
#Query("select a from TableA, TableB b where a.property = b.property")
works.
In JPQL you should use SQL syntax (for the most part) meaning that != is expressed with <>. See also this wiki article
Related
I currently have the query stated below. I know this works as a SQL query, but because I am using the EntityManager, from javax.persistence, it requires JPQL. And I don't know JPQL. If there is a way to rewrite this in JPQL that would be nice.
Query q = entityManager.createNativeQuery("
WITH original AS (SELECT *, COUNT(ref) as c FROM Tri WHERE triH IN :list GROUP BY ref
SELECT ref FROM original WHERE c = :amtTri");
q.setParameter("list", posTri);
q.setParameter("amtTri", posTri.size());
Actual query:
WITH original AS (SELECT *, COUNT(ref) as c FROM Tri WHERE triH IN :list GROUP BY ref
SELECT ref FROM original WHERE c = :amtTri
I am trying to do this in a Quarkus project using the Repository method, if there is a way to use that, that would also be fine
Thanks in advance!
I believe that using the EntityManager don't obligates you to use JPQL, you can also use Native Queries.
As your query looks not so simple (for me at least), I would do it using Native Queries and not JPQL. You can run Native Queries using the EntityManager from javax.persistence. This tutorial explains how you can do this.
I and my colleague are working to make a framework for our company.
We are using Hibernate as DAO and Spring as IOC.
We would like to use hibernate filters to reduce our result set based on some restrictions, but we are confused how to use it properly!
Consider entity A has reference to B and B to C and C to D ant etc...
How can we write a filter that when i search the A entity, all the filters defined on B, C and D applied.
We have used Hibernate filters in very cases but we have not already succeeded in such these cases.
Have we got any other solutions for filtering data ?
I stuck into similar problem recently. The only solution I've found is to write a full SQL with all conditions which you need and retrieve all IDs of A (if we're creating a filter in the A entity) which matches your requirements and then in the filter check, whether ID is in those IDs or not. It would be something like
#FilterDef(name = "filterName",
parameters = {#ParamDef(name = "param", type = "string")},
defaultCondition = "id in (select a.id from A a
join B b on a.b_id = b.id
join C c on b.c_id = c.id
where c.some_property = 2)")
However, I'm not sure this is a good solution for some large queries.
I have a named query as below;
#NamedQuery(name = "MyEntityClass.findSomething", query = "SELECT item FROM MyTable mytbl")
Now I want to append dynamic sort clause to this query (based on UI parameters)
Can I get an example using JPQL for doing the same (like how to set a dynamic ORDER BY in the Entity class)
I have already tried using CriteriaQuery, but was looking for a JPQL implementation now.
NamedQueries are by definition NOT dynamic, it is not correct to change them programmatically.
So the way to go is to create a JPQL query (but not a named query) like this:
TypedQuery<MyEntity> query = em.createdQuery("SELECT item FROM MyEntity item ORDER BY "+sortingCol, MyEntity.class);
On the other hand, if you REALLY want to use the named query, you could do that the following way:
#NamedQuery(name = "MyEntityClass.findSomething", query = MyEntity.NAMED_QUERY)
#Entity
public class MyEntity {
public static final NAMED_QUERY= "SELECT item FROM MyTable mytbl";
//+your persistent fields/properties...
}
//and later in your code
TypedQuery<MyEntity> query = entityManager.createQuery(MyEntity.NAMED_QUERY + " ORDER BY " + sortingCol, MyEntity.class);
Complementing for JPA 2.1
As of JPA 2.1 it is possible to define named queries programmatically.
This can be achieved using entityManagerFactory.addNamedQuery(String name, Query).
Example:
Query q = this.em.createQuery("SELECT a FROM Book b JOIN b.authors a WHERE b.title LIKE :title GROUP BY a");
this.em.getEntityManagerFactory().addNamedQuery("selectAuthorOfBook", q);
// then use like any namedQuery
Reference here
This can be useful, for instance, if you have the orderby field defined as a application parameter. So, when the application starts up or on the first run of the query, you could define the NamedQuery with the defined OrderBy field.
On the other side, if your OrderBy can be changed anytime (or changes a lot), then you need dynamic queries instead of NamedQuery (static). It would not worth to (re)create a NamedQuery every time (by performance).
#NamedQuery
Persistence Provider converts the named queries from JPQL to SQL at deployment time.
Until now, there is no feature to create/update the query with #NamedQuery annotation at runtime.
On the other hand, you can use Reflection API, to change the annotation value at runtime. I think It is not solution, also it is not you wanted .
em.createQuery()
Persistence Provider converts the dynamic queries from JPQL to SQL every time it is invoked.
The main advantage of using dynamic queries is that the query can be created based on the user inputs.
I'm porting some complex JPQL queries in a large Hibernate/JPA2 application to use QueryDSL 2.3.0, and I'm stuck on one.
My Client entity contains
#ManyToMany
private List<Group> groups;
My existing query fragment is
EXISTS(SELECT g FROM Group g WHERE g MEMBER OF slr.groups AND
UPPER(g.description) LIKE :group)
The QueryDSL code generation has produced the following in my QClient class:
public final SimplePath<java.util.List<Group>> groups =
createSimple("groups", java.util.List.class);
The code generation using SimplePath doesn't let me use the in or contains methods to query membership. I think I need a CollectionPath instead. Is there a way to annotate the Client class so that QueryDSL uses the correct type for querying a collection?
I have an answer. This looks like a bug introduced in QueryDSL 2.2.5, which only happens when working in Eclipse.
The correct solution is to not use Eclipse to generate the source (don't enable annotation processing). Instead, I'm using m2eclipse and generating the source in Maven.
For reference, my first workaround was to extend the generated QClient class with my own QQClient class, which adds one member:
public final ListPath<Group, QGroup> fixedgroups =
createList("groups", Group.class, QGroup.class);
At that point the equivalent to my original query is:
QGroup g = QGroup.group;
JPQLSubQuery subquery = new JPQLSubQuery().from(g);
subquery = subquery.where(slr.fixedgroups.contains(g),
g.description.upper().like("%" + group.toUpperCase() + "%"));
query = query.where(subquery.exists());
(query is the larger query this is part of. slr is an instance of QQClient brought into the outer query by a left join.)
How can I write a JPA query using MONTH function just like sql query?
#NamedQuery(name="querybymonth", query="select t from table1 t where MONTH(c_Date) = 5")
When I use the above pattern for query, I get an error: unexpected token - MONTH.
If you are using EclipseLink (2.1) you can use the FUNC() function to call any database function that is not defined in the JPA JPQL spec.
i.e.
FUNC('MONTH', c_Date)
In JPA 2.1 (EclipseLink 2.5) the FUNCTION syntax becomes part of the specification (and replaces the EclipseLink-specific FUNC).
If you are using TopLink Essentials, you cannot do this in JPQL, but you can define a TopLink Expression query for it (similar to JPA 2.0 criteria), or use native SQL.
Also if you are using any JPA 2.0 provider and using a Criteria query there is a function() API that can be used to define this.
I want to query YEAR(itemDate) but the function doesn't exit, then i saw the SUBSTRING() function so what i did was
Select q from table where SUBSTRING(itemDate, 1, 4)='2011'
and it works for me! hope it helps!
if you need you a dynamic variable, you can do that too. here :poDate is the year which is deifned in the setParameter();
#NamedQuery(name = "PurchaseOrders.findByYear", query = "SELECT p FROM PurchaseOrders p WHERE SUBSTRING(p.poDate, 1, 4) = :poDate")
Query q = em.createNamedQuery("PurchaseOrders.findByYear");
q.setParameter("poDate", s_year+"");
but if your okay with your solutions, that'll be fine. i just find JPA faster to execute.
The MONTH() function exists in Hibernate HQL but is not a standard JPA function. Maybe your JPA provider has some proprietary equivalent but you didn't mention it. If it doesn't, fall back on native SQL.
I am using Toplink Essentials for the same. Please help, if any function exists in Toplink. Thanks.
To my knowledge, TopLink doesn't have a direct equivalent. So either use a native SQL query or maybe a TopLink Expression query (not sure about this, and not sure this is available in TopLink Essentials).
Following worked for me with hibernate (4.3.9.Final) & JPA 2.1.
#NamedQuery(name = "PartyEntity.findByAID", query = "select distinct psc.party from PartyShortCode psc where (psc.shortCode = :aidNumber or FUNCTION('REPLACE',psc.accountReference,' ','') = :aidNumber) and psc.sourceSystem in :sourceSystem")
if your class holds a date type variable, you can use a query like this:
#Query("select m from Movement m where m.id_movement_type.id=1 and SubString(cast(m.date as text),1,4) = :year")
List<Movement> buysForYear(#Param("year") String year);