How to convert an SQL query to HQL or JPQL

Hibernate ORM
1

I’m going crazy behind the hql, how do I convert this query into that language?

select n.*
from nominativo n
left join nominativo_istituzione ni on n.token_nominativo = ni.token_nominativo
left join associato_ente ae on ni.token_istituzione = ae.token_associato
left join adesione a on ae.token_ente = a.token_nominativo
where a.token_adesione = 1750011366
2

First, you need to map the tables to entities. Then, the joins should be expressed as associations.

Once you do that, the HQL would look like this:

select n
from Nominativo n
left join n.istituzione i 
left join i.associatoEnte ae  
left join ae.adesione a
where a.tokenAdesione = :token

For more details about mapping entities, check out the Hibernate User Guide.

3

unfortunately the mapping is different and I can not change it.
In NominativoIstituzione there is the Nominativo joinColumn.
In Adesione there is the Nominativo JoinColumn.
in associato ente is the following
associatoEnte
@ManyToOne(fetch = FetchType.LAZY, cascade = { CascadeType.PERSIST, CascadeType.MERGE }, optional = false)
@JoinColumn(name = “token_associato”)
private Nominativo associato;

@ManyToOne(fetch = FetchType.LAZY, cascade = { CascadeType.PERSIST, CascadeType.MERGE }, optional = false)
@JoinColumn(name = "token_ente")
private Nominativo ente;
4

unfortunately the mapping is different and I can not change it.
In NominativoIstituzione there is the Nominativo joinColumn.
In Adesione there is the Nominativo JoinColumn.
in associato ente is the following
associatoEnte

@ManyToOne(fetch = FetchType.LAZY, cascade = { CascadeType.PERSIST, CascadeType.MERGE }, optional = false)
@JoinColumn(name = “token_associato”)
private Nominativo associato;

@ManyToOne(fetch = FetchType.LAZY, cascade = { CascadeType.PERSIST, CascadeType.MERGE }, optional = false)
@JoinColumn(name = "token_ente")
private Nominativo ente;
5

Without seeing the existing JPA entity mapping, I won’t be able to tell you if you can map that query to JPQL.