Bonjour,
J'ai une question à propos de la clause "order-by" dans une requete "one-to-many". J'ai une base de données contenant 3 tables : A, B et C. Le code des classes Java correspondant aux tables est le suivant :
Classe A:
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| package database;
import java.util.Set;
public class A implements java.io.Serializable {
private Integer id;
private Set<B> listB;
public A() {
}
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public Set<B> getListB() {
return listB;
}
public void setListB(Set<B> listB) {
this.listB = listB;
}
} |
Classe B :
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| package database;
public class B implements java.io.Serializable {
private Integer id;
private A a;
private C c;
public B() {
}
public Integer getId() {
return this.id;
}
public void setId(Integer id) {
this.id = id;
}
public A getA() {
return a;
}
public void setA(A a) {
this.a = a;
}
public C getC() {
return c;
}
public void setC(C c) {
this.c = c;
}
} |
Classe C :
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| package database;
public class C implements java.io.Serializable {
private Integer id;
private int num;
public C() {
}
public Integer getId() {
return this.id;
}
public void setId(Integer id) {
this.id = id;
}
public int getNum() {
return this.num;
}
public void setNum(int num) {
this.num = num;
}
} |
Les fichiers de mapping sont les suivants :
Table A :
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| <?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
<hibernate-mapping package="database">
<class name="A" table="A">
<id
column="id"
name="Id"
type="integer"
>
<generator class="increment" />
</id>
<set name="listB" cascade="all, delete-orphan" inverse="true" lazy="true" fetch="select" order-by="c.Id asc">
<key column="a_id"/>
<one-to-many class="B"/>
</set>
</class>
</hibernate-mapping> |
Table B :
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| <?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
<hibernate-mapping package="database">
<class name="B" table="B">
<id
column="id"
name="Id"
type="integer"
>
<generator class="increment" />
</id>
<many-to-one name="a" class="A" fetch="select">
<column name="a_id" not-null="true" />
</many-to-one>
<many-to-one name="c" class="C" fetch="select">
<column name="c_id" not-null="true" />
</many-to-one>
</class>
</hibernate-mapping> |
Table C :
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| <?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd" >
<hibernate-mapping package="database">
<class name="C" table="C">
<id
name="Id"
type="integer"
column="id"
>
<generator class="increment"/>
</id>
<property
name="Num"
column="num"
type="integer"
not-null="true"
length="10"
/>
</class>
</hibernate-mapping> |
Ma question concerne la clause "order-by" dans le fichier A.hbm. J'aimerais
ordonner ma liste, non pas selon c.Id, mais selon c.Num, comme par exemple :
<set name="listB" cascade="all, delete-orphan" inverse="true" lazy="true" fetch="select" order-by="c.Num asc">
Cependant, lorsque j'écris ça, j'obtiens cette erreur :
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| Exception in thread "main" org.hibernate.exception.SQLGrammarException: could not initialize a collection: [database.A.listB#1]
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:92)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
at org.hibernate.loader.Loader.loadCollection(Loader.java:2069)
at org.hibernate.loader.collection.CollectionLoader.initialize(CollectionLoader.java:62)
at org.hibernate.persister.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:628)
at org.hibernate.event.def.DefaultInitializeCollectionEventListener.onInitializeCollection(DefaultInitializeCollectionEventListener.java:83)
at org.hibernate.impl.SessionImpl.initializeCollection(SessionImpl.java:1853)
at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:366)
at org.hibernate.collection.AbstractPersistentCollection.read(AbstractPersistentCollection.java:108)
at org.hibernate.collection.PersistentSet.iterator(PersistentSet.java:186)
at Test.main(Test.java:36)
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLSyntaxErrorException: Unknown column 'listb0_.c.Num' in 'order clause'
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
at java.lang.reflect.Constructor.newInstance(Unknown Source)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.Util.getInstance(Util.java:386)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1054)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4120)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:4052)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2503)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2664)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2815)
at com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2155)
at com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:2322)
at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:208)
at org.hibernate.loader.Loader.getResultSet(Loader.java:1849)
at org.hibernate.loader.Loader.doQuery(Loader.java:718)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:270)
at org.hibernate.loader.Loader.loadCollection(Loader.java:2062)
... 8 more |
Je commence à peine l'utilisation d'hibernate, j'ai vu des posts à propos de l'utilisation de la classe "Criteria", mais je ne vois pas comment je peux l'utiliser dans mon fichier de mapping.
A moins que je doive coder la requête dans le Java, mais dans ce cas, où dois-je le faire ?
Merci d'avance,
Lauriane
Clause order-by dans le fichier de mapping
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