Can I persist a Map containing a List as Value
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Can I persist a Map containing a List as Value
by adi-31
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Hi
I persisted a map like this: private Map<String, String> instructions; How can I persist a map that contains a List as value? private Map<String, List<String>> instructions; Thanks a lot! Regards Adrian _______________________________________________ eclipselink-users mailing list eclipselink-users@... https://dev.eclipse.org/mailman/listinfo/eclipselink-users |
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Re: Can I persist a Map containing a List as Value
by tware
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You will likely need an extra object to do this. Something like:
private Map<String, ListHolder> instructions; @Entity public class ListHolder{ @id private int id; private List instructions; ... } It should be pretty easy to write some business methods that make this mapping transparent to the users of the API. -Tom adi@... wrote: > Hi > > I persisted a map like this: > private Map<String, String> instructions; > > How can I persist a map that contains a List as value? > private Map<String, List<String>> instructions; > > Thanks a lot! > > Regards Adrian > > _______________________________________________ > eclipselink-users mailing list > eclipselink-users@... > https://dev.eclipse.org/mailman/listinfo/eclipselink-users eclipselink-users mailing list eclipselink-users@... https://dev.eclipse.org/mailman/listinfo/eclipselink-users |
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Re: Can I persist a Map containing a List as Value
by adi-31
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Hi
I tryed this with the following code: @Entity public class TestEntity { @Id @GeneratedValue private int id; @OneToMany(cascade = { CascadeType.ALL }) @BasicMap(fetch = FetchType.EAGER, keyColumn = @Column(name = "key"), valueColumn = @Column(name = "value")) @CollectionTable(name = "map") private Map<String, TestHolder> map; public void setMap(Map<String, TestHolder> map) { this.map = map; } public Map<String, TestHolder> getMap() { return map; } } @Entity public class TestHolder { @Id @GeneratedValue private int id; private String value; public void setValue(String value) { this.value = value; } public String getValue() { return value; } } private void test() { factory = Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME); EntityManager em = factory.createEntityManager(); em.getTransaction().begin(); TestEntity testEntity = new TestEntity(); Map<String, TestHolder> map = new HashMap<String, TestHolder>(); TestHolder value = new TestHolder("value"); map.put("key", value ); testEntity.setMap(map ); em.persist(testEntity); em.getTransaction().commit(); em.close(); } Definition of table map: CREATE TABLE MAP ( ID NUMBER(10) NOT NULL, VALUE VARCHAR2(255 BYTE), KEY VARCHAR2(255 BYTE) ) Then I get the error message: Internal Exception: java.sql.SQLException: Ungültiger Spaltentyp Error Code: 17004 Call: INSERT INTO map (ID, value, key) VALUES (?, ?, ?) bind => [1, bom.TestHolder@e34726, key] How can I store the object as entity? Thanks a lot! Regards Adrian Zitat von Tom Ware <tom.ware@...>: > You will likely need an extra object to do this. Something like: > > private Map<String, ListHolder> instructions; > > @Entity > public class ListHolder{ > @id > private int id; > > private List instructions; > > ... > } > > It should be pretty easy to write some business methods that make > this mapping > transparent to the users of the API. > > -Tom > > adi@... wrote: >> Hi >> >> I persisted a map like this: >> private Map<String, String> instructions; >> >> How can I persist a map that contains a List as value? >> private Map<String, List<String>> instructions; >> >> Thanks a lot! >> >> Regards Adrian >> >> _______________________________________________ >> eclipselink-users mailing list >> eclipselink-users@... >> https://dev.eclipse.org/mailman/listinfo/eclipselink-users > _______________________________________________ > eclipselink-users mailing list > eclipselink-users@... > https://dev.eclipse.org/mailman/listinfo/eclipselink-users > _______________________________________________ eclipselink-users mailing list eclipselink-users@... https://dev.eclipse.org/mailman/listinfo/eclipselink-users |
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Re: Can I persist a Map containing a List as Value
by tware
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You will have to map your "map" element as a normal OneToMany - rather than as a
BasicMap. The key is that you it actually takes two levels go get your mapping to look the way you want. i.e. - TestEntity.map is a OneToMany with a MapKey to TestHolder - TestHolder has a ManyToOne backpointer to TestEntity - TestHolder also contains a BasicCollection that represents your list - it is then possible to write business methods in TestEntity that can get the list for an item in "map" without exposing the API user to the fact that TestHolder exists. -Tom adi@... wrote: > Hi > > I tryed this with the following code: > > @Entity > public class TestEntity { > @Id @GeneratedValue private int id; > > @OneToMany(cascade = { CascadeType.ALL }) > @BasicMap(fetch = FetchType.EAGER, keyColumn = @Column(name = "key"), > valueColumn = @Column(name = "value")) > @CollectionTable(name = "map") > private Map<String, TestHolder> map; > > public void setMap(Map<String, TestHolder> map) { > this.map = map; > } > > public Map<String, TestHolder> getMap() { > return map; > } > } > > @Entity > public class TestHolder { > @Id @GeneratedValue private int id; > > private String value; > > public void setValue(String value) { > this.value = value; > } > > public String getValue() { > return value; > } > } > > private void test() { > factory = > Persistence.createEntityManagerFactory(PERSISTENCE_UNIT_NAME); > EntityManager em = factory.createEntityManager(); > > em.getTransaction().begin(); > > TestEntity testEntity = new TestEntity(); > Map<String, TestHolder> map = new HashMap<String, TestHolder>(); > TestHolder value = new TestHolder("value"); > map.put("key", value ); > testEntity.setMap(map ); > em.persist(testEntity); > > em.getTransaction().commit(); > em.close(); > } > > Definition of table map: > CREATE TABLE MAP > ( > ID NUMBER(10) NOT NULL, > VALUE VARCHAR2(255 BYTE), > KEY VARCHAR2(255 BYTE) > ) > > Then I get the error message: > Internal Exception: java.sql.SQLException: Ungültiger Spaltentyp > Error Code: 17004 > Call: INSERT INTO map (ID, value, key) VALUES (?, ?, ?) > bind => [1, bom.TestHolder@e34726, key] > > How can I store the object as entity? > > Thanks a lot! > > Regards Adrian > > > > > Zitat von Tom Ware <tom.ware@...>: > >> You will likely need an extra object to do this. Something like: >> >> private Map<String, ListHolder> instructions; >> >> @Entity >> public class ListHolder{ >> @id >> private int id; >> >> private List instructions; >> >> ... >> } >> >> It should be pretty easy to write some business methods that make this >> mapping >> transparent to the users of the API. >> >> -Tom >> >> adi@... wrote: >>> Hi >>> >>> I persisted a map like this: >>> private Map<String, String> instructions; >>> >>> How can I persist a map that contains a List as value? >>> private Map<String, List<String>> instructions; >>> >>> Thanks a lot! >>> >>> Regards Adrian >>> >>> _______________________________________________ >>> eclipselink-users mailing list >>> eclipselink-users@... >>> https://dev.eclipse.org/mailman/listinfo/eclipselink-users >> _______________________________________________ >> eclipselink-users mailing list >> eclipselink-users@... >> https://dev.eclipse.org/mailman/listinfo/eclipselink-users >> > > > > _______________________________________________ > eclipselink-users mailing list > eclipselink-users@... > https://dev.eclipse.org/mailman/listinfo/eclipselink-users eclipselink-users mailing list eclipselink-users@... https://dev.eclipse.org/mailman/listinfo/eclipselink-users |
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