jpql

问题 I'm writing a Dao to fetch all Messages relevant to a Person . But I can't find the correct JPQL syntax. In my model: a Person has multiple Roles (I pass these into the query as a parameter: Set of enum values). a Message is relevant to multiple Roles . So I want to find all messages relevant to a person: SELECT m FROM Message m WHERE m.roles [contains one of] :userRoles Giving it :userRoles as a Set<Role> parameter. What is the correct syntax for that missing [contains one of] section? I've

问题 I am designing a multilanguage system using Java, and during my research to find the best database model to store multi-localized text, I came accross Vertabelo's blog and this wonderful design, from here: Database model However, as there are lots of objects to be localized in the project, I am avoiding to write all the Dao's myself, and stick with JPA, if possible. The thing is that I don't know much of JPA yet, so I googled for available solutions to this problem, and found another great

问题 I am designing a multilanguage system using Java, and during my research to find the best database model to store multi-localized text, I came accross Vertabelo's blog and this wonderful design, from here: Database model However, as there are lots of objects to be localized in the project, I am avoiding to write all the Dao's myself, and stick with JPA, if possible. The thing is that I don't know much of JPA yet, so I googled for available solutions to this problem, and found another great

问题 I am designing a multilanguage system using Java, and during my research to find the best database model to store multi-localized text, I came accross Vertabelo's blog and this wonderful design, from here: Database model However, as there are lots of objects to be localized in the project, I am avoiding to write all the Dao's myself, and stick with JPA, if possible. The thing is that I don't know much of JPA yet, so I googled for available solutions to this problem, and found another great

问题 I am designing a multilanguage system using Java, and during my research to find the best database model to store multi-localized text, I came accross Vertabelo's blog and this wonderful design, from here: Database model However, as there are lots of objects to be localized in the project, I am avoiding to write all the Dao's myself, and stick with JPA, if possible. The thing is that I don't know much of JPA yet, so I googled for available solutions to this problem, and found another great

问题 I already asked about my situation and didn't find a proper solution. After some additional search I think I know the source problem although don't know how to resolve it. As mentioned I have: @Table(name = "role__parent") @IdClass(RoleAssociationKey.class) @Data public class RoleAssociation implements Serializable { @Id @JoinColumn(name = "has_parent_role_id") private Role node; @Id @JoinColumn(name = "is_parent_for_role_id") private Role parent; ... } @Data class RoleAssociationKey

问题 I have the followed trouble. There is an entity Distributor who is connected with the ManyToMany relationship to entity town: @Entity public class Distributor{ @ManyToMany @JoinTable( name = "GS_DISTRIBUTOR_TOWN", joinColumns = @JoinColumn(name = "CD_DISTRIBUTOR"), inverseJoinColumns = @JoinColumn(name = "CD_TOWN") ) private List<Town> towns; .... } Then the entity town is also in relation with District @Entity public class Town{ @ManyToMany(mappedBy="towns") private List<Distributor>

问题 I'm performing a Query to my DB in JPA . The Query "queries" 4 tables, and the result aggregates columns from that different tables. My Query is something like: Query query = em.createQuery("SELECT o.A, o.B, o.C, e.D, c.E FROM Table1 o, Table2 i, Table3 e, Table4 c WHERE o.X = i.X AND i.Y = e.Y AND i.Z = c.Z"); How can I get the query result and extract the different fields? I created a class (MyObject) that represents each item of the result list, and I want to convert the query

问题 i'm using JPA 2.1 (Hibernate 4 as impl) and Spring Data JPA 1.9.0. How do i implement full text search? My scenario is as follows. I have a User entity and on the UI a have a table which display's most of users properties and i want the user to give text box enter there a search term and search in all properties. I see 2 options to do this: Load all users users from DB and filter them in Java Write a JPQL query with many ORs and LIKE % :searchString % Option 1 is not good for performance but

问题 I have two entities: class A { @OneToMany(mappedBy = "a") List<B> bs; // getter/ setter } class B { @ManyToOne A a; // getter/ setter } To delete one b, I first need to invalidate that relationship. "Traditionally" I would do something like that: A a = em.getReference(A.class, entityIdA) B b = em.getReference(B.class, entityIdB); a.getBs().remove(b); b.setA(null); em.remove(b); This is not very performant, if the List of a 's is getting large (a few hundreds in my case). I know I can also use