One to many relationship using java collections
I am facing issue on how to store and then retrieve data . In my program which is simple java class i am retrieving data at 3 places from an xml. i need to store this temporarly in particular fashion as data is related and needed to be used later on at end program to generate report.
first data i am retireving is employee names eg Tom , Reggie, Martha.
Second data is department (Each employee belongs to 1 or many department ) so in this case
Tom : Billing
Reggie : Admin , HR
Martha : IT
Third data is Department number (This has 1 : 1 relationship with Department )
Billing :01
Admin :02
HR:03
IT:04
So when i am parsing xml first i am getting employee data, then department and lastly department number. I need to store it in collection in such way later on i can retireve and link data and use it.....
Which java collections i should use....
Any hints or guidance ....
Well, the simplest approach is to initially load the employees objects into a List<Employee>. Initially they store the department number only. Then load the departments, probably into a Map<Integer, Department>. Having popluated such a map you then loop through the Employee list, connecting looking up the deparment number in the map and connecting Employee to Department as you wish. (An Employee would probably had a reference to the Department, the Department might contain a List<Employee>).
The implementations to use depend on how you'll use them. HashMaps are faster than TreeMaps, but a TreeMap orders. LinkedLists are faster to process in sequence than ArrayList, slower to process at random.
Similar Messages
-
Mapping a one to many relationship using fluent api
Hi I can't map my domains to match the database, since database is already created, I can't create or remove any other extra table.
Database
CREATE TABLE PLAYER (Id Int, Name varchar(100), PRIMARY KEY (Id))
CREATE TABLE POSITION (Id Int, Name varchar(100), PRIMARY KEY (Id))
CREATE TABLE CHAMPIONSHIP (Id Int, Name varchar(100), PRIMARY KEY (Id))
CREATE TABLE RELATED (PlayerId Int, PositionId Int, ChampionshipId int,
FOREIGN KEY (PlayerId) references PLAYER(id),
FOREIGN KEY (PositionId) references POSITION(id),
FOREIGN KEY (ChampionshipId) references CHAMPIONSHIP(id),
CONSTRAINT AK_RELATED UNIQUE(PlayerId,PositionId,ChampionshipId))
Domains:
public class Player
public Player()
this.Relateds = new List<Related>();
public int Id {get;set;}
public string Name { get; set; }
public virtual ICollection<Related> Relateds { get; set; }
public class Position
{ public int Id {get;set;}
public string Name { get; set; } public virtual ICollection<Related> Relateds { get; set; }
public class Championship
{ public int Id {get;set;}
public string Name { get; set; } public virtual ICollection<Related> Relateds { get; set; }
public class Related
public int PlayerId { get; set; }
public Player Player{ get; set; }
public int PositionId { get; set; }
public Position Position { get; set; }
public int ChamionshipId { get; set; }
public Championship Championship { get; set; }
FLUENT API:
modelBuilder.Entity<Player>().HasKey(m => m.Id);
modelBuilder.Entity<Player>().Property(m => m.Name).IsRequired();
modelBuilder.Entity<Position>().HasKey(m => m.Id);
modelBuilder.Entity<Position>().Property(m => m.Name).IsRequired();
modelBuilder.Entity<Championship>().HasKey(m => m.Id);
modelBuilder.Entity<Championship>().Property(m => m.Name).IsRequired();
Seed.cs
public DbSet<Player> Players { get; set; }
public DbSet<Position> Positions { get; set; }
public DbSet<Championship> Championships { get; set; }
private void Seed2(ApplicationDbContext context)
string[] playerNames = new string[] { "Adam", "John", "Lucas" };
string[] positionNames = new string[] { "Sniper", "Camper", "Assalt" };
string[] championshipNames = new string[] { "BF4", "CS1.6", "TF2" };
int relations = 3;
try
foreach (var name in playerNames)
if (!this.Players.Any(m => m.Name == name))
Player player = new Player { Name = name };
context.Players.Add(player);
foreach (var name in positionNames)
if (!this.Players.Any(m => m.Name == name))
Position position = new Position { Name = name };
context.Positions.Add(position);
foreach (var name in championshipNames)
if (!this.Championship.Any(m => m.Name == name))
Championship championship = new Championship { Name = name };
context.Championships.Add(championship);
context.SaveChanges();
for (int i = 1; i <= relations; i++)
var player = context.Players.ToList()[i];
var position = context.Positions.ToList()[i];
var championship = context.Championships.ToList()[i];
if (!context.Relateds.Any(m =>
context.Players.Any(t => m.PlayerId == t.Id)
&& context.Positions.Any(t => m.PositionId == t.Id)
&& context.Championships.Any(t => m.ChampionshipId == t.Id)))
Related related = new Related
Player = player,
Position = position,
Championship = championship
player.Relateds.Add(related);
context.Entry(player).State = EntityState.Modified;
context.SaveChanges();
catch (Exception ex)
throw;
I'm not able to insert into the Related table, I think the fluent api is not maped well, how can I fix it?Hello,
>>I'm not able to insert into the Related table, I think the fluent api is not maped well, how can I fix it?
As you mentions, your database already exists, so I assume that you are using database first approach, then, as far as I know, the fluent API is made only for Code-First approach and we don't need the fluent API if we create your model via Database-First.
For database first approach, we just need to import existed tables to the designer surface by “Update Model From Database”. And with your provided model, I noticed that the related table does not contain a primary constraint, in Entity Framework, a table
without the primary key would be treated as a view that is read only. So please create a primary constraint for the related table as:
CREATE TABLE RELATED (PlayerId Int, PositionId Int, ChampionshipId int,
FOREIGN KEY (PlayerId) references PLAYER(id),
FOREIGN KEY (PositionId) references POSITION(id),
FOREIGN KEY (ChampionshipId) references CHAMPIONSHIP(id),
PRIMARY KEY CLUSTERED (PlayerId ASC, PositionId ASC,ChampionshipId asc),
CONSTRAINT AK_RELATED UNIQUE(PlayerId,PositionId,ChampionshipId))
With your provided tables, after adding this constraint, the Related table could add a new row as:
using (DFDBEntities db=new DFDBEntities())
RELATED related = new RELATED() { PlayerId = 1, ChampionshipId = 1, PositionId = 1 };
db.RELATEDs.Add(related);
db.SaveChanges();
Regards.
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Using data from one-to-many relationship
Hi,
i have an one-to-many relationship among two tables similar to the structure as in the below reference:-
[One-to-many-reference|http://docs.oracle.com/cd/E23507_01/Platform.20073/RepositoryGuide/html/s1204repositoryexamplefonetomanymappi01.html]
taking this as an example, i have the city's name with me. using this data in the addr_tbl in the 'address' item-descriptor, i need to get the value of the 'name' in the usr_tbl in the 'user' item descriptor. i will have the list of 'city' with me which i have to iterate and display the corresponding 'name'.
will i be able to perform this in the jsp itself or does it have to be done in java? a sample code snippet or reference for doing this will be of much help.
thank you.Thanks a lot, Sheik.
if i have to do the reverse, ie for the 'name' in the usr_tbl of user item-descriptor i have to fetch the 'city' values in the addr_tbl, will it suffice if i do the following?
<dsp:droplet name="/atg/dynamo/droplet/RQLQueryForEach">
<dsp:param name="queryRQL" value="name=\"sirius\""/>
<dsp:param name="repository"
value="/com/MyRepository"/>
<dsp:param name="itemDescriptor" value="user"/>
<dsp:oparam name="output">
<dsp:valueof param="element.address.city"/>
</dsp:oparam>
</dsp:droplet> -
What types of containers need to be used for one-to-many relationships
While looking at toplink examples, I noticed that synchronized containers only are being used for one-to-many relationships even though it's not required by the documentation.
Is it required?
Also how does merge affect it? I'm gettning concurrent modification exceptions from time to time, while using iterators for containers from these relationships.
Does it mean that I have to use enumeration on vectors only and toplink merge isn't atomic? So there is no isolation when toplink merges the data from unit of work into identity maps?
There is nothing about thread-safety and threading aspects of accessing containers for CollectionMapping based relationships. Please advise.Non synchronized containers can be used but may require some extra code to handle concurrent access. If you are accessing the objects from the shared cache (not cloned in a UnitOfWork) then you will need to isolate your iteration within a synchronized block, synchronized on the collection itself, or handle the ConncurrentModificationException if they happen rarely.
Because these are shared instances of these collections other threads may be writing to them while they are being read from.
--Gordon -
Urgent : java bean having bidirectional one to many relationship
Hi,
We have complex requirement in our application.
We need to copy java bean having bidirectional one to many relationship to another javabean having bidirectional one to many relationship..
E.g
Class Basket1 {
public String color;
pubic String type;
public List<Basket1> basketList = new ArrayList()
Class Basket2 {
public String color;
pubic String type;
public List<Basket2> basketList = new ArrayList()
We need to exact copy Basket1 to Basket2. We are in trouble to copy List of child because we do not have how many child Basket1 have of same type..
Can someone help us how we can implement such kind of complex object bidirectional one to many relationship??I can't see anything bidirectional about these relationships. What I can see is a couple of BasketN classes that look identical so I don't know why they both exist, and they both contain lists of themselves as members, which suggests some kind of tree structure. Nothing bidirectional there. I can see tat these things can form circular object graphs but I don't see why you would want to do that.
We need to exact copy Basket1 to Basket2And I don't know what that means. Please explain. -
Unable to read one-to-many relations using Hibernate
Hi,
I am trying with a very simple one-to-many relationship. When I am storing the objects, there are no problems. But when I am trying to read out the collection, it says invalid descriptor index. Please help.
Regards,
Hibernate version:
hibernate-3.1rc2
Mapping documents:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="Parent">
<id name="id">
<generator class="identity"/>
</id>
<set name="children">
<key column="parent_id"/>
<one-to-many class="Child"/>
</set>
</class>
<class name="Child">
<id name="id">
<generator class="identity"/>
</id>
<property name="name"/>
</class>
</hibernate-mapping>
Code between sessionFactory.openSession() and session.close():
The Parent class:
public class Parent
private Long id ;
private Set children;
Parent(){}
public Long getId()
return id;
public void setId(Long id)
this.id=id;
public Set getChildren()
return children;
public void setChildren(Set children)
this.children=children;
The Child class:
public class Child
private Long id;
private String name;
Child(){}
public Long getId()
return id;
private void setId(Long id)
this.id=id;
public String getName()
return name;
public void setName(String name)
this.name=name;
The Main class:
public class PCManager
public static void main(String[] args)
PCManager mgr = new PCManager();
List lt = null;
if (args[0].equals("store"))
mgr.createAndStoreParent(new HashSet(3));
else if (args[0].equals("list"))
mgr.listEvents();
HibernateUtil.getSessionFactory().close();
private void createAndStoreParent(HashSet s)
HibernateUtil.getSessionFactory().getCurrentSession().beginTransaction();
Parent p1 = new Parent();
int size = 3;
for (int i=size; i>0; i--)
Child c = new Child();
c.setName("Child"+i);
s.add(c);
p1.setChildren (s);
Iterator elems = s.iterator();
do {
Child ch = (Child) elems.next();
HibernateUtil.getSessionFactory().getCurrentSession().save(ch);
}while(elems.hasNext());
HibernateUtil.getSessionFactory().getCurrentSession().save(p1);
HibernateUtil.getSessionFactory().getCurrentSession().getTransaction().commit();
private void listEvents()
HibernateUtil.getSessionFactory().getCurrentSession().beginTransaction();
Parent result = (Parent) HibernateUtil.getSessionFactory().getCurrentSession().load(Parent.class, new Long(1));
System.out.println("Id is :"+ result.getId());
Set children = result.getChildren();
Iterator elems = children.iterator();
do {
Child ch = (Child) elems.next();
System.out.println("Child Name"+ ch.getName());
}while(elems.hasNext());
HibernateUtil.getSessionFactory().getCurrentSession().getTransaction().commit();
Full stack trace of any exception that occurs:
When I run with "hbm2ddl.auto" property as validate and trying to list the contents, I get the following out put.
C:\Documents and Settings\mirza\Desktop\hibernate-3.1rc2\MyHibernate>ant run -Da
ction=list
Buildfile: build.xml
clean:
[delete] Deleting directory C:\Documents and Settings\mirza\Desktop\hibernate
-3.1rc2\MyHibernate\bin
[mkdir] Created dir: C:\Documents and Settings\mirza\Desktop\hibernate-3.1rc
2\MyHibernate\bin
copy-resources:
[copy] Copying 4 files to C:\Documents and Settings\mirza\Desktop\hibernate
-3.1rc2\MyHibernate\bin
compile:
[javac] Compiling 5 source files to C:\Documents and Settings\mirza\Desktop\
hibernate-3.1rc2\MyHibernate\bin
run:
[java] 09:09:23,433 INFO Environment:474 - Hibernate 3.1 rc2
[java] 09:09:23,449 INFO Environment:489 - loaded properties from resource
hibernate.properties: {hibernate.cglib.use_reflection_optimizer=true, hibernate
.cache.provider_class=org.hibernate.cache.HashtableCacheProvider, hibernate.dial
ect=org.hibernate.dialect.SQLServerDialect, hibernate.max_fetch_depth=1, hiberna
te.jdbc.use_streams_for_binary=true, hibernate.format_sql=true, hibernate.query.
substitutions=yes 'Y', no 'N', hibernate.proxool.pool_alias=pool1, hibernate.cac
he.region_prefix=hibernate.test, hibernate.jdbc.batch_versioned_data=true, hiber
nate.connection.pool_size=1}
[java] 09:09:23,465 INFO Environment:519 - using java.io streams to persis
t binary types
[java] 09:09:23,465 INFO Environment:520 - using CGLIB reflection optimize
r
[java] 09:09:23,481 INFO Environment:550 - using JDK 1.4 java.sql.Timestam
p handling
[java] 09:09:23,559 INFO Configuration:1257 - configuring from resource: /
hibernate.cfg.xml
[java] 09:09:23,559 INFO Configuration:1234 - Configuration resource: /hib
ernate.cfg.xml
[java] 09:09:23,872 INFO Configuration:460 - Reading mappings from resourc
e: PCMapping.hbm.xml
[java] 09:09:24,013 INFO HbmBinder:266 - Mapping class: Parent -> Parent
[java] 09:09:24,045 INFO HbmBinder:266 - Mapping class: Child -> Child
[java] 09:09:24,045 INFO Configuration:1368 - Configured SessionFactory: n
ull
[java] 09:09:24,061 INFO Configuration:1014 - processing extends queue
[java] 09:09:24,061 INFO Configuration:1018 - processing collection mappin
gs
[java] 09:09:24,061 INFO HbmBinder:2233 - Mapping collection: Parent.child
ren -> Child
[java] 09:09:24,076 INFO Configuration:1027 - processing association prope
rty references
[java] 09:09:24,076 INFO Configuration:1049 - processing foreign key const
raints
[java] 09:09:24,155 INFO DriverManagerConnectionProvider:41 - Using Hibern
ate built-in connection pool (not for production use!)
[java] 09:09:24,170 INFO DriverManagerConnectionProvider:42 - Hibernate co
nnection pool size: 1
[java] 09:09:24,170 INFO DriverManagerConnectionProvider:45 - autocommit m
ode: false
[java] 09:09:24,170 INFO DriverManagerConnectionProvider:80 - using driver
: sun.jdbc.odbc.JdbcOdbcDriver at URL: jdbc:odbc:MySQL
[java] 09:09:24,170 INFO DriverManagerConnectionProvider:86 - connection p
roperties: {}
[java] 09:09:24,264 INFO SettingsFactory:77 - RDBMS: Microsoft SQL Server,
version: 08.00.0194
[java] 09:09:24,264 INFO SettingsFactory:78 - JDBC driver: JDBC-ODBC Bridg
e (SQLSRV32.DLL), version: 2.0001 (03.85.1117)
[java] 09:09:24,296 INFO Dialect:100 - Using dialect: org.hibernate.dialec
t.SQLServerDialect
[java] 09:09:24,311 INFO TransactionFactoryFactory:31 - Using default tran
saction strategy (direct JDBC transactions)
[java] 09:09:24,327 INFO TransactionManagerLookupFactory:33 - No Transacti
onManagerLookup configured (in JTA environment, use of read-write or transaction
al second-level cache is not recommended)
[java] 09:09:24,327 INFO SettingsFactory:125 - Automatic flush during befo
reCompletion(): disabled
[java] 09:09:24,327 INFO SettingsFactory:129 - Automatic session close at
end of transaction: disabled
[java] 09:09:24,343 INFO SettingsFactory:144 - Scrollable result sets: ena
bled
[java] 09:09:24,343 INFO SettingsFactory:152 - JDBC3 getGeneratedKeys(): d
isabled
[java] 09:09:24,343 INFO SettingsFactory:160 - Connection release mode: au
to
[java] 09:09:24,358 INFO SettingsFactory:184 - Maximum outer join fetch de
pth: 1
[java] 09:09:24,358 INFO SettingsFactory:187 - Default batch fetch size: 1
[java] 09:09:24,358 INFO SettingsFactory:191 - Generate SQL with comments:
disabled
[java] 09:09:24,358 INFO SettingsFactory:195 - Order SQL updates by primar
y key: disabled
[java] 09:09:24,358 INFO SettingsFactory:338 - Query translator: org.hiber
nate.hql.ast.ASTQueryTranslatorFactory
[java] 09:09:24,374 INFO ASTQueryTranslatorFactory:21 - Using ASTQueryTran
slatorFactory
[java] 09:09:24,374 INFO SettingsFactory:203 - Query language substitution
s: {no='N', yes='Y'}
[java] 09:09:24,374 INFO SettingsFactory:209 - Second-level cache: enabled
[java] 09:09:24,374 INFO SettingsFactory:213 - Query cache: disabled
[java] 09:09:24,374 INFO SettingsFactory:325 - Cache provider: org.hiberna
te.cache.HashtableCacheProvider
[java] 09:09:24,374 INFO SettingsFactory:228 - Optimize cache for minimal
puts: disabled
[java] 09:09:24,374 INFO SettingsFactory:233 - Cache region prefix: hibern
ate.test
[java] 09:09:24,405 INFO SettingsFactory:237 - Structured second-level cac
he entries: disabled
[java] 09:09:24,437 INFO SettingsFactory:257 - Echoing all SQL to stdout
[java] 09:09:24,452 INFO SettingsFactory:264 - Statistics: disabled
[java] 09:09:24,452 INFO SettingsFactory:268 - Deleted entity synthetic id
entifier rollback: disabled
[java] 09:09:24,452 INFO SettingsFactory:283 - Default entity-mode: POJO
[java] 09:09:24,593 INFO SessionFactoryImpl:155 - building session factory
[java] 09:09:24,938 INFO SessionFactoryObjectFactory:82 - Not binding fact
ory to JNDI, no JNDI name configured
[java] 09:09:24,954 INFO SchemaValidator:99 - Running schema validator
[java] 09:09:24,954 INFO SchemaValidator:107 - fetching database metadata
[java] 09:09:24,954 INFO Configuration:1014 - processing extends queue
[java] 09:09:24,954 INFO Configuration:1018 - processing collection mappin
gs
[java] 09:09:24,954 INFO Configuration:1027 - processing association prope
rty references
[java] 09:09:24,954 INFO Configuration:1049 - processing foreign key const
raints
[java] 09:09:24,985 WARN JDBCExceptionReporter:71 - SQL Error: 0, SQLState
: S1002
[java] 09:09:24,985 ERROR JDBCExceptionReporter:72 - [Microsoft][ODBC SQL S
erver Driver]Invalid Descriptor Index
[java] 09:09:25,001 ERROR SchemaValidator:129 - Error closing connection
[java] java.sql.SQLException: [Microsoft][ODBC SQL Server Driver]Invalid transaction state
[java] Initial SessionFactory creation failed.org.hibernate.exception.Gener
icJDBCException: could not get table metadata: Child
[java] java.lang.ExceptionInInitializerError
[java] at HibernateUtil.<clinit>(Unknown Source)
[java] at PCManager.listEvents(Unknown Source)
[java] at PCManager.main(Unknown Source)
[java] Caused by: org.hibernate.exception.GenericJDBCException: could not g
et table metadata: Child
[java] at org.hibernate.exception.SQLStateConverter.handledNonSpecificE
xception(SQLStateConverter.java:91)
[java] at sun.jdbc.odbc.JdbcOdbc.createSQLException(JdbcOdbc.java:6879)
[java] at sun.jdbc.odbc.JdbcOdbc.standardError(JdbcOdbc.java:7036)
[java] at sun.jdbc.odbc.JdbcOdbc.SQLDisconnect(JdbcOdbc.java:2988)
[java] at sun.jdbc.odbc.JdbcOdbcDriver.disconnect(JdbcOdbcDriver.java:9
80)
[java] at sun.jdbc.odbc.JdbcOdbcConnection.close(JdbcOdbcConnection.jav
a:739)
[java] at org.hibernate.tool.hbm2ddl.SchemaValidator.validate(SchemaVal
idator.java:125)
[java] at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryIm
pl.java:299)
[java] at org.hibernate.cfg.Configuration.buildSessionFactory(Configura
tion.java:1145)
[java] at HibernateUtil.<clinit>(Unknown Source)
[java] at org.hibernate.exception.SQLStateConverter.convert(SQLStateCon
verter.java:79)
[java] at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExcep
tionHelper.java:43)
[java] at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExcep
tionHelper.java:29)
[java] at org.hibernate.tool.hbm2ddl.DatabaseMetadata.getTableMetadata(
DatabaseMetadata.java:100)
[java] at org.hibernate.cfg.Configuration.validateSchema(Configuration.
java:946)
[java] at org.hibernate.tool.hbm2ddl.SchemaValidator.validate(SchemaVal
idator.java:116)
[java] at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryIm
pl.java:299)
[java] at org.hibernate.cfg.Configuration.buildSessionFactory(Configura
tion.java:1145)
[java] ... 3 more
[java] Caused by: java.sql.SQLException: [Microsoft][ODBC SQL Server Driver
]Invalid Descriptor Index
[java] at sun.jdbc.odbc.JdbcOdbc.createSQLException(JdbcOdbc.java:6879)
[java] at sun.jdbc.odbc.JdbcOdbc.standardError(JdbcOdbc.java:7036)
[java] at sun.jdbc.odbc.JdbcOdbc.SQLGetDataString(JdbcOdbc.java:3862)
[java] at sun.jdbc.odbc.JdbcOdbcResultSet.getDataString(JdbcOdbcResultS
et.java:5561)
[java] at sun.jdbc.odbc.JdbcOdbcResultSet.getString(JdbcOdbcResultSet.j
ava:338)
[java] at sun.jdbc.odbc.JdbcOdbcResultSet.getString(JdbcOdbcResultSet.j
ava:395)
[java] at PCManager.listEvents(Unknown Source)
[java] at PCManager.main(Unknown Source)
[java] at org.hibernate.tool.hbm2ddl.TableMetadata.<init>(TableMetadata
.java:30)
[java] at org.hibernate.tool.hbm2ddl.DatabaseMetadata.getTableMetadata(
DatabaseMetadata.java:85)
[java] ... 7 more
[java] Exception in thread "main"
[java] Java Result: 1
BUILD SUCCESSFUL
Total time: 4 seconds
Name and version of the database you are using:
Microsoft SQLServer2000
The generated SQL (show_sql=true):
When the program is run with "hbm2ddl.auto" property as create, I get the following output.
C:\Documents and Settings\mirza\Desktop\hibernate-3.1rc2\MyHibernate>ant run -Daction=store
Buildfile: build.xml
clean:
[delete] Deleting directory C:\Documents and Settings\mirza\Desktop\hibernate
-3.1rc2\MyHibernate\bin
[mkdir] Created dir: C:\Documents and Settings\mirza\Desktop\hibernate-3.1rc
2\MyHibernate\bin
copy-resources:
[copy] Copying 4 files to C:\Documents and Settings\mirza\Desktop\hibernate
-3.1rc2\MyHibernate\bin
compile:
[javac] Compiling 5 source files to C:\Documents and Settings\mirza\Desktop\
hibernate-3.1rc2\MyHibernate\bin
run:
[java] 09:12:54,820 INFO Environment:474 - Hibernate 3.1 rc2
[java] 09:12:54,836 INFO Environment:489 - loaded properties from resource
hibernate.properties: {hibernate.cglib.use_reflection_optimizer=true, hibernate
.cache.provider_class=org.hibernate.cache.HashtableCacheProvider, hibernate.dial
ect=org.hibernate.dialect.SQLServerDialect, hibernate.max_fetch_depth=1, hiberna
te.jdbc.use_streams_for_binary=true, hibernate.format_sql=true, hibernate.query.
substitutions=yes 'Y', no 'N', hibernate.proxool.pool_alias=pool1, hibernate.cac
he.region_prefix=hibernate.test, hibernate.jdbc.batch_versioned_data=true, hiber
nate.connection.pool_size=1}
[java] 09:12:54,852 INFO Environment:519 - using java.io streams to persis
t binary types
[java] 09:12:54,852 INFO Environment:520 - using CGLIB reflection optimize
r
[java] 09:12:54,867 INFO Environment:550 - using JDK 1.4 java.sql.Timestam
p handling
[java] 09:12:54,946 INFO Configuration:1257 - configuring from resource: /
hibernate.cfg.xml
[java] 09:12:54,946 INFO Configuration:1234 - Configuration resource: /hib
ernate.cfg.xml
[java] 09:12:55,259 INFO Configuration:460 - Reading mappings from resourc
e: PCMapping.hbm.xml
[java] 09:12:55,400 INFO HbmBinder:266 - Mapping class: Parent -> Parent
[java] 09:12:55,447 INFO HbmBinder:266 - Mapping class: Child -> Child
[java] 09:12:55,447 INFO Configuration:1368 - Configured SessionFactory: n
ull
[java] 09:12:55,447 INFO Configuration:1014 - processing extends queue
[java] 09:12:55,447 INFO Configuration:1018 - processing collection mappin
gs
[java] 09:12:55,447 INFO HbmBinder:2233 - Mapping collection: Parent.child
ren -> Child
[java] 09:12:55,463 INFO Configuration:1027 - processing association prope
rty references
[java] 09:12:55,479 INFO Configuration:1049 - processing foreign key const
raints
[java] 09:12:55,557 INFO DriverManagerConnectionProvider:41 - Using Hibern
ate built-in connection pool (not for production use!)
[java] 09:12:55,557 INFO DriverManagerConnectionProvider:42 - Hibernate co
nnection pool size: 1
[java] 09:12:55,557 INFO DriverManagerConnectionProvider:45 - autocommit m
ode: false
[java] 09:12:55,573 INFO DriverManagerConnectionProvider:80 - using driver
: sun.jdbc.odbc.JdbcOdbcDriver at URL: jdbc:odbc:MySQL
[java] 09:12:55,573 INFO DriverManagerConnectionProvider:86 - connection p
roperties: {}
[java] 09:12:55,651 INFO SettingsFactory:77 - RDBMS: Microsoft SQL Server,
version: 08.00.0194
[java] 09:12:55,667 INFO SettingsFactory:78 - JDBC driver: JDBC-ODBC Bridg
e (SQLSRV32.DLL), version: 2.0001 (03.85.1117)
[java] 09:12:55,682 INFO Dialect:100 - Using dialect: org.hibernate.dialec
t.SQLServerDialect
[java] 09:12:55,698 INFO TransactionFactoryFactory:31 - Using default tran
saction strategy (direct JDBC transactions)
[java] 09:12:55,714 INFO TransactionManagerLookupFactory:33 - No Transacti
onManagerLookup configured (in JTA environment, use of read-write or transaction
al second-level cache is not recommended)
[java] 09:12:55,714 INFO SettingsFactory:125 - Automatic flush during befo
reCompletion(): disabled
[java] 09:12:55,714 INFO SettingsFactory:129 - Automatic session close at
end of transaction: disabled
[java] 09:12:55,729 INFO SettingsFactory:144 - Scrollable result sets: ena
bled
[java] 09:12:55,729 INFO SettingsFactory:152 - JDBC3 getGeneratedKeys(): d
isabled
[java] 09:12:55,745 INFO SettingsFactory:160 - Connection release mode: au
to
[java] 09:12:55,745 INFO SettingsFactory:184 - Maximum outer join fetch de
pth: 1
[java] 09:12:55,745 INFO SettingsFactory:187 - Default batch fetch size: 1
[java] 09:12:55,745 INFO SettingsFactory:191 - Generate SQL with comments:
disabled
[java] 09:12:55,745 INFO SettingsFactory:195 - Order SQL updates by primar
y key: disabled
[java] 09:12:55,745 INFO SettingsFactory:338 - Query translator: org.hiber
nate.hql.ast.ASTQueryTranslatorFactory
[java] 09:12:55,777 INFO ASTQueryTranslatorFactory:21 - Using ASTQueryTran
slatorFactory
[java] 09:12:55,792 INFO SettingsFactory:203 - Query language substitution
s: {no='N', yes='Y'}
[java] 09:12:55,792 INFO SettingsFactory:209 - Second-level cache: enabled
[java] 09:12:55,792 INFO SettingsFactory:213 - Query cache: disabled
[java] 09:12:55,792 INFO SettingsFactory:325 - Cache provider: org.hiberna
te.cache.HashtableCacheProvider
[java] 09:12:55,808 INFO SettingsFactory:228 - Optimize cache for minimal
puts: disabled
[java] 09:12:55,808 INFO SettingsFactory:233 - Cache region prefix: hibern
ate.test
[java] 09:12:55,808 INFO SettingsFactory:237 - Structured second-level cac
he entries: disabled
[java] 09:12:55,839 INFO SettingsFactory:257 - Echoing all SQL to stdout
[java] 09:12:55,839 INFO SettingsFactory:264 - Statistics: disabled
[java] 09:12:55,839 INFO SettingsFactory:268 - Deleted entity synthetic id
entifier rollback: disabled
[java] 09:12:55,839 INFO SettingsFactory:283 - Default entity-mode: POJO
[java] 09:12:55,980 INFO SessionFactoryImpl:155 - building session factory
[java] 09:12:56,325 INFO SessionFactoryObjectFactory:82 - Not binding fact
ory to JNDI, no JNDI name configured
[java] 09:12:56,341 INFO Configuration:1014 - processing extends queue
[java] 09:12:56,341 INFO Configuration:1018 - processing collection mappin
gs
[java] 09:12:56,341 INFO Configuration:1027 - processing association prope
rty references
[java] 09:12:56,341 INFO Configuration:1049 - processing foreign key const
raints
[java] 09:12:56,356 INFO Configuration:1014 - processing extends queue
[java] 09:12:56,356 INFO Configuration:1018 - processing collection mappin
gs
[java] 09:12:56,356 INFO Configuration:1027 - processing association prope
rty references
[java] 09:12:56,372 INFO Configuration:1049 - processing foreign key const
raints
[java] 09:12:56,372 INFO SchemaExport:153 - Running hbm2ddl schema export
[java] 09:12:56,388 DEBUG SchemaExport:171 - import file not found: /import
.sql
[java] 09:12:56,388 INFO SchemaExport:180 - exporting generated schema to
database
[java] 09:12:56,403 DEBUG SchemaExport:283 -
[java] alter table Child
[java] drop constraint FK3E104FC976A59A
[java] 09:12:56,466 DEBUG SchemaExport:283 -
[java] drop table Child
[java] 09:12:56,544 DEBUG SchemaExport:283 -
[java] drop table Parent
[java] 09:12:56,654 DEBUG SchemaExport:283 -
[java] create table Child (
[java] id numeric(19,0) identity not null,
[java] name varchar(255) null,
[java] parent_id numeric(19,0) null,
[java] primary key (id)
[java] )
[java] 09:12:56,779 DEBUG SchemaExport:283 -
[java] create table Parent (
[java] id numeric(19,0) identity not null,
[java] primary key (id)
[java] )
[java] 09:12:56,873 DEBUG SchemaExport:283 -
[java] alter table Child
[java] add constraint FK3E104FC976A59A
[java] foreign key (parent_id)
[java] references Parent
[java] 09:12:56,952 INFO SchemaExport:200 - schema export complete
[java] 09:12:56,952 WARN JDBCExceptionReporter:48 - SQL Warning: 5701, SQL
State: 01000
[java] 09:12:56,952 WARN JDBCExceptionReporter:49 - [Microsoft][ODBC SQL S
erver Driver][SQL Server]Changed database context to 'master'.
[java] 09:12:56,952 WARN JDBCExceptionReporter:48 - SQL Warning: 5703, SQL
State: 01000
[java] 09:12:56,952 WARN JDBCExceptionReporter:49 - [Microsoft][ODBC SQL S
erver Driver][SQL Server]Changed language setting to us_english.
[java] 09:12:56,983 INFO SessionFactoryImpl:432 - Checking 0 named queries
[java] Hibernate:
[java] insert
[java] into
[java] Child
[java] (name)
[java] values
[java] (?) select
[java] scope_identity()
[java] Hibernate:
[java] insert
[java] into
[java] Child
[java] (name)
[java] values
[java] (?) select
[java] scope_identity()
[java] Hibernate:
[java] insert
[java] into
[java] Child
[java] (name)
[java] values
[java] (?) select
[java] scope_identity()
[java] Hibernate:
[java] insert
[java] into
[java] Parent
[java] default
[java] values
[java] select
[java] scope_identity()
[java] Hibernate:
[java] update
[java] Child
[java] set
[java] parent_id=?
[java] where
[java] id=?
[java] Hibernate:
[java] update
[java] Child
[java] set
[java] parent_id=?
[java] where
[java] id=?
[java] Hibernate:
[java] update
[java] Child
[java] set
[java] parent_id=?
[java] where
[java] id=?
[java] 09:12:57,390 INFO SessionFactoryImpl:831 - closing
[java] 09:12:57,390 INFO DriverManagerConnectionProvider:147 - cleaning up
connection pool: jdbc:odbc:MySQL
BUILD SUCCESSFUL
Total time: 5 seconds
Debug level Hibernate log excerpt:
Included in the above description.That's not the right mapping for the 1:m relationship in Hibernate.
First of all, I believe the recommendation is to have a separate .hbm.xml file for each class, so you should have one for Parent and Child.
Second, you'll find the proper syntax for a one-to-many relationship here:
http://www.hibernate.org/hib_docs/v3/reference/en/html/tutorial.html#tutorial-associations
See if those help.
The tutorial docs for Hibernate are quite good. I'd recommend going through them carefully.
% -
One-to-many relationship within one bean
hello all,
Does S1 support a container managed one-to-many relationship to itself?
I used the verifer to verify my DD and the error is reported. (this prototype is migrated from weblogic6.1 and I use the S1 migration tool for the DD generation)
-----------------database schema-----------------
CREATE TABLE t_class_a
c_name VARCHAR2(255),
one_class_a_for_ma2918_id VARCHAR2(32), /* untruncated name: one_class_a_for_many_class_a_id */
object_id VARCHAR2(32) NOT NULL
CREATE UNIQUE INDEX t_class_a_id_PK ON t_class_a ( object_id );
ALTER TABLE t_class_a ADD ( CONSTRAINT t_class_a_id_PK PRIMARY KEY ( object_id ) USING INDEX );
ALTER TABLE t_class_a ADD ( CONSTRAINT FK_0 FOREIGN KEY ( one_class_a_for_ma2918_id ) REFERENCES t_class_a ( object_id ) );
---------------------------ejb-jar.xml------------------
<abstract-schema-name>ClassABean</abstract-schema-name>
<cmp-field>
<field-name>objectId</field-name></cmp-field>
<cmp-field>
<field-name>name</field-name></cmp-field>
<primkey-field>objectId</primkey-field>
<relationships>
<ejb-relation>
<ejb-relation-name>manyClassA_oneClassA</ejb-relation-name>
<ejb-relationship-role>
<description>optional</description>
<ejb-relationship-role-name>OneClassA-in-manyClassA_oneClassA</ejb-relationship-role-name>
<multiplicity>One</multiplicity>
<relationship-role-source>
<ejb-name>ClassAEJB</ejb-name></relationship-role-source>
<cmr-field>
<cmr-field-name>manyClassAsForOneClassA</cmr-field-name>
<cmr-field-type>java.util.Collection</cmr-field-type></cmr-field></ejb-relationship-role>
<ejb-relationship-role>
<description>optional</description>
<ejb-relationship-role-name>ManyClassA-in-manyClassA_oneClassA</ejb-relationship-role-name>
<multiplicity>Many</multiplicity>
<relationship-role-source>
<ejb-name>ClassAEJB</ejb-name></relationship-role-source>
<cmr-field>
<cmr-field-name>oneClassAForManyClassA</cmr-field-name>
</cmr-field>
</ejb-relationship-role>
</ejb-relation>
</relationships>
-----------sun-cmp-mapping.xml--------
<sun-cmp-mapping>
<schema>mySchema</schema>
<entity-mapping>
<ejb-name>ClassAEJB</ejb-name>
<table-name>T_CLASS_A</table-name>
<cmp-field-mapping>
<field-name>objectId</field-name>
<column-name>OBJECT_ID</column-name></cmp-field-mapping>
<cmp-field-mapping>
<field-name>name</field-name>
<column-name>C_NAME</column-name></cmp-field-mapping>
<cmr-field-mapping>
<cmr-field-name>manyClassAsForOneClassA</cmr-field-name>
<column-pair>
<column-name>T_CLASS_A.OBJECT_ID</column-name>
<column-name>T_CLASS_A.ONE_CLASS_A_FOR_MA2918_ID</column-name></column-pair></cmr-field-mapping></entity-mapping></sun-cmp-mapping></sun-cmp-mappings>
I beleive the migration tool missing the cmr-filed mapping for the oneClassAForManyClassA relation role.
but even if I add this mapping it still can't pass the verifiy.
So do I miss any thing or I can conclude S1 not support this one-to many self relation?
Any hint would be welcome.It does.
There is a known problem with parsing self-referenced relationship info - the one side (with <multiplicity> Many) must be the first in the <ejb-relation> entry.
Regards,
Marina -
How to insert data in a one-to-many relationship
How do you insert data into the client, my model entity beans have a one-to-many relationship.
PARENT ENTITY BEAN
PARENT-ID
PARENT-NAME
The ejbCreate(Integer parentID,String name)
CHILD ENTITY BEAN
CHILD-ID
CHILD-NAME
PARENT-ID(foreign key of PARENTID).
ejbCreate(Integer parentID,String name,String foreignparentID)
In a jsp page i collect the parent details and 3 corresponding chld details in a text box.
Can you please tell me how do i proceed from here...
ie. how to i insert data into the entity beans..
Do i pass the child as a collection, and within parents ejbCreate() method do i lookup for the childs home interface and insert one -by -one from the collection.
1. Considering the above example, can some one pls tell how the ejbCreate() mehod signatures, for the parent and child entity beans should be.
2. Pls also show some sample client code as to how to make an insertion.
3. In case you are passing a collection of child data, then in what format does one have to insert into a collection and also how does the container know how to insert the values in the child table , bcoz we are passing as a collection.
4.In case collections cannot be inserted do we need to iterate into the collection in parent's ejbCreate() method, and manually insert into the database of the childtable, thereby creating child entity beans.
Thanks for your time and support...
regards
kartikHi,
3. In this case of course child's ejbCreate(and postCreate) looks like
ejbCreate(Integer childID,String name,ParentLocal parent) {
setId(Id);
setName(name);
ejbPostCreate(Integer childID,String name,ParentLocal parent) {
setParent(parent);
Here you don't need IDs, but it happens only using Locals, not Remotes, if I'm not wrong. Container does it itself.
1. Of course, if you have parent.getChildren() and parent.setChildren() then you don't need any loops, but it should be done anyway in postCreate, because in ejbCreate there no parent exists yet.
Once more 3: example - I'm using JBoss 3.2.5 as EJB container. It has tomcat inside and EJB and JSP+Struts use the same jvm. It means for me that I don't need to use remote interfaces, just locals. And in this case I can implement ejb-relations. So, a have the abstract method parent.getChildren() which returns Collection of ChildLocal - s and method parent.setChildren(Collection childrenLocals) which creates/modifies children by itself.
I have not used remotes for a long time, but as I remember it was not possible to implement ejb-relations using remotes.
regards,
Gio -
Newbie: one to many relationship SQL error
Greetings all-
This is probably a slam dunk for you JDO experts. I'm a JDO newbie, working
with an existing schema in MySQL. I have a one to many relationship between
two tables:
Table "company":
Fields:
company_id: int(11) -- primary key
name : varchar(64)
division : varchar(64)
Table "company_products"
Fields:
company_id: int(11) -- foreign key to table company
product_name: varchar(64)
product_description: varchar(64)
So, I created the corresponding classes:
public class Company {
private int companyID;
private String company_name;
private String division;
// Array of CompanyProduct
private ArrayList companyProducts;
// .. methods omitted
public class CompanyProduct {
private int companyID;
private String productName;
private String productDesc;
// Methods omitted
Then I created the "package.jdo" file:
<?xml version="1.0"?>
<jdo>
<package name="com.packexpo.db">
<class name="Company">
<extension vendor-name="tt" key="table" value="company"/>
<extension vendor-name="tt" key="pk-column" value="company_id"/>
<extension vendor-name="tt" key="lock-column" value="none"/>
<extension vendor-name="tt" key="class-column" value="none"/>
<field name="companyID">
<extension vendor-name="tt" key="data-column" value="company_id"/>
</field>
<field name="name">
<extension vendor-name="tt" key="data-column" value="name"/>
<extension vendor-name="tt" key="column-length" value="64"/>
</field>
<field name="division">
<extension vendor-name="tt" key="data-column" value="division"/>
<extension vendor-name="tt" key="column-length" value="64"/>
</field>
<field name="companyProducts">
<collection element-type="com.packexpo.db.CompanyProduct"/>
<extension vendor-name="tt" key="inverse" value="companyID"/>
</field>
</class>
<class name="CompanyProduct">
<extension vendor-name="tt" key="table" value="company_product"/>
<extension vendor-name="tt" key="pk-column" value="company_id"/>
<extension vendor-name="tt" key="lock-column" value="none"/>
<extension vendor-name="tt" key="class-column" value="none"/>
<field name="companyID">
<extension vendor-name="tt" key="data-column" value="company_id"/>
</field>
<field name="productName">
<extension vendor-name="tt" key="data-column" value="product_name"/>
<extension vendor-name="tt" key="column-length" value="64"/>
</field>
<field name="productDesc">
<extension vendor-name="tt" key="data-column"
value="product_description"/>
<extension vendor-name="tt" key="column-length" value="64"/>
</field>
</class>
</package>
</jdo>
Enhancement works fine. I successfully query and retrive Company objects
from the database, but as soon as I try to get the list of CompanyProducts,
I get an SQL Error:
javax.jdo.JDODataStoreException: [SQL=SELECT company.COMPANYPRODUCTSX FROM
company WHERE company.company_id = 82061]
E0610 Error in executeQuery()
E0606 executeQuery() error --
E0701 Error in getResult().
E0708 Command results in error - 1054 Unknown column
'company.COMPANYPRODUCTSX' in 'field list'
NestedThrowables:
com.solarmetric.kodo.impl.jdbc.sql.SQLExceptionWrapper: [SQL=SELECT
company.COMPANYPRODUCTSX FROM company WHERE company.company_id = 82061]
E0610 Error in executeQuery()
E0606 executeQuery() error --
E0701 Error in getResult().
E0708 Command results in error - 1054 Unknown column
'company.COMPANYPRODUCTSX' in 'field list'
I know i have probably set up the package.jdo file incorrectly, but I'm at a
loss for what I did wrong.
Any suggestions?
Thanks!
-MikeHi,
915766 wrote:
I need to write sql for below requirement:
table structure is
serial no LPN
1 4
2 4
3 6
4 6
5 6
6 3
7 3
8 3
9 1
I have to pick distinct 'LPN' like below:That sounds like a job for "GROUP BY lpn".
(any serial no can be picked for the distinct LPN)It looks like you're displaying the lowest serial_no for each lpn. That's easy to do, using the aggregate MIN function.
results needs to be as below:
serial no LPN
1 4
3 6
6 3
9 1
Please suggest with sql.Here's one way:
SELECT MIN (serial_no) AS serial_no
, lpn
FROM table_x
GROUP BY lpn
ORDER BY lpn -- if wanted
I hope this answers your question.
If not, post a little sample data (CREATE TABLE and INSERT statements, relevant columns only), and also post the results you want from that data.
Explain, using specific examples, how you get those results from that data.
Always say which version of Oracle you're using (e.g., 11.2.0.2.0).
See the forum FAQ {message:id=9360002} -
One to many relationship leads to recursion?
Hi,
I've created a web services function which returns an object retrieved from a database using the persistence api (the class was generated by the Netbeans 5.5 "Entity Class from Database" feature.
I can successfully return an object which has no foreign keys. However, when I try to retrieve an entity which is on either side of a 1:N relationship, I receive a stackOverflowError.
Here's my sample schema (I'm using Derby bundled with SJAS 9 for testing)
create table Address (
Id int not null,
StreetName varchar(255),
City varchar(255),
PostalCode varchar(255),
Party int,
primary key (Id)
create table Party (
Id int,
Name varchar(255),
primary key(Id)
alter table Address add constraint foreign key (Party) references Party;So as you can see, one Party might have many addresses.
I can retrieve either an Address or Party from the database using something like:
em.createNamedQuery("Party.findById")
.setParameter("id", 1)
.getSingleResult();When I try to return it, I get a stackOverflowError in the server log. I'm using the default Toplink provider so enabling full logging on this, I can see the SQL.
When retrieving an address, it selects all of the address fields and correctly binds the supplied Id value. It then performs a select on the Party table using the Address.Party value. This in turn causes it to attempt to retrieve an Address. After three queries, the error is thrown.
I can't see why the above schema should cause this problem. Where an Address is requested, I would expect it to retrieve the address fields, including the value of the Party field but not the Party object itself. On the other hand. when a Party is retrieved, I would expect it to recurse through and return a collection of Address objects.
Have I misunderstood this or am I missing some fundamental point about JAX-WS?
Thanks for your help,
-PhilYou have to set both sides of the relations...
for example to do this in a more seamless manner:
public UserProfile
public void addLog (UserActivityLog activity)
logs.add (activity);
if (!equals (activity.getUserProfile ()))
activity.setUserProfile (this);
Now this is the most primitive of ways to maintain two sided relations.
There are a lot of other patterns to get around this.
If you want to set the UserActivityLog to a specific UserProfile without
having a firm reference to ther UserProfile, you should get the object
from the database/persistenceManager... as you are using application
identity, you can do something like pm.getObjectById.
JDO does not do magic references. If you set something to null, it will
remain null until you set it.
Srini wrote:
Hi Guys
I am trying to create a one to many relationship between 2 JDOs.
UserProfile - User JDO having user info
UserActivityLog - JDO having user log info
UserProfile -- UserActivityLog
1 many
UserProfile - has a collection of UserActivityLog objects
UserActivityLog - has a reference to UserProfile
Qn 1:
I created a UserProfile along with a collection of 2 UserActivityLog
objects.
Navigation:
Now given a UserProfile object,i am able to get the UserActivityLog objects.
But given a UserActivityLog object ,i get a NULL UserProfile object.
Issues:
Why this is happening???Do i need to set the reference for "UserProfile" in
UserActivityLog before inserting???
If so,then how do i add a UserActivityLog to an existing
UserProfile???cos,if i create a UserActivityLog with reference to
UserProfile ,then it will throw a Duplicate Key violation for UserProfile as
it is already persisted in DB.
It will be great if you can direct me to some one to many relationship
examples already implemented.
Thanks
Srini
Stephen Kim
[email protected]
SolarMetric, Inc.
http://www.solarmetric.com -
One to many relationship in hibernate
I am very much new to hibernate,
for testing purpose I am using JPA annotations and hibernate.
While testing one to many relationship , I got a problem
I have a PurchaseOrder class and OrderLine class having one to many relationship.
package orderpackage;
import java.util.ArrayList;
import java.util.List;
import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.OneToMany;
@Entity
public class PurchaseOrder {
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
private int id;
@OneToMany(cascade=CascadeType.ALL,mappedBy="order")
private List <OrderLine> orderLine = new ArrayList<OrderLine>();
public PurchaseOrder(String orderName) {
this.orderName = orderName;
public List<OrderLine> getOrderLine() {
return orderLine;
public void setOrderLine(List<OrderLine> orderLine) {
this.orderLine = orderLine;
private String orderName;
public int getId() {
return id;
public void setId(int id) {
this.id = id;
public String getOrderName() {
return orderName;
public void setOrderName(String orderName) {
this.orderName = orderName;
OrderLine.java
package orderpackage;
import javax.persistence.CascadeType;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.ManyToOne;
@Entity
public class OrderLine {
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
private int id;
private String itemName;
private int qty;
@ManyToOne(cascade=CascadeType.ALL)
private PurchaseOrder order;
public OrderLine(String itemName, int qty) {
this.itemName = itemName;
this.qty = qty;
public PurchaseOrder getOrder() {
return order;
public void setOrder(PurchaseOrder order) {
this.order = order;
public int getId() {
return id;
public void setId(int id) {
this.id = id;
public String getItemName() {
return itemName;
public void setItemName(String itemName) {
this.itemName = itemName;
public int getQty() {
return qty;
public void setQty(int qty) {
this.qty = qty;
OrderTest.java
package orderpackage;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class OrderTest {
public static void main(String[] args) {
PurchaseOrder order = new PurchaseOrder("order no 1");
OrderLine orderLine1 = new OrderLine("item1",25);
OrderLine orderLine2 = new OrderLine("item2",28);
OrderLine orderLine3 = new OrderLine("item3",38);
OrderLine orderLine4 = new OrderLine("item4",48);
order.getOrderLine().add(orderLine1);
order.getOrderLine().add(orderLine2);
order.getOrderLine().add(orderLine3);
order.getOrderLine().add(orderLine4);
SessionFactory sessionFactory = new Configuration().configure().buildSessionFactory();
Session session = sessionFactory.openSession();
session.beginTransaction();
session.persist(order);
session.getTransaction().commit();
session.close();
I can see Order and Order Line are get persisted but Order Line table don't have order_id populated automatically. Please help me out.That is because you're not setting it, obviously. Nowhere in your code are you actually populating the order property of the orderlines.
-
Hi I have a big problem :)
I want to use one to many relationships.
One yable with primary key, foreign key view_id. The second table on the many side with primary key view_id and another primary key.
The problem is that ejbc gives the followin error:
" [java] In relationship 'ViewType-SView', role 'ViewType-Has-SView', a weblogic-relationship-role element contains the wrong number of column mappings. A single column mapping must be given for each primary key column in the bean referenced by the mapping."
And that makes no sense for me. Any ideas?weblogic-relationship-role element column mappings should be the same as defined in
<ejb-relationship-role>
<multiplicity></multiplicity>
</ejb-relationship-role>
Erno wrote:
Hi I have a big problem :)
I want to use one to many relationships.
One yable with primary key, foreign key view_id. The second table on the many side with primary key view_id and another primary key.
The problem is that ejbc gives the followin error:
" [java] In relationship 'ViewType-SView', role 'ViewType-Has-SView', a weblogic-relationship-role element contains the wrong number of column mappings. A single column mapping must be given for each primary key column in the bean referenced by the mapping."
And that makes no sense for me. Any ideas? -
Need help mapping one-to-many relationship
[Sorry, inadvertently cross-posted]
Hello,
I have a one-to-many mapping question that's probably a no-brainer for the
experts of the group out there. My problem is that I can't get a collection
of Items for a given Theme to be populated and I don't know if it's a
problem in my system.jdo or in my classes (or both). For example, for Theme
10,
I want a collection of two Items, item_ids 1 and 2.
I have db tables named ITEM and THEME with the following layouts:
ITEM
|==========================================================|
| item_id(pk) | item_name | item_number | theme_id(fk) |
|==========================================================|
| 1 | This is Item1 | 1234 | 10 |
| 2 | This is Item2 | 2954 | 10 |
| 3 | This is Item3 | 2094 | 17 |
| 4 | This is Item4 | 946 | 11 |
| ... |
|==========================================================|
THEME
|=======================================|
| theme_id(pk) | theme_description |
|=======================================|
| 4 | Space |
| 10 | Town |
| 11 | Train |
| 17 | Pirate |
| ... |
|=======================================|
I have two PersistenceCapable classes that map to the above tables:
package com.lego.data;
public class Item
public int item_id;
private String item_number;
private String item_name;
private int theme_id;
public Theme theme;
public String toString()
return
item_number+":"+item_name+":"+theme.getCode()+":"+theme.getDescription();
package com.lego.data;
import java.util.*;
public class Theme
public int theme_id;
public String theme_description;
public Collection items;
public String toString()
return theme_id+":"+theme_description;
and here is my system.jdo file:
<?xml version = "1.0" encoding = "US-ASCII"?>
<jdo>
<package name="com.lego.data">
<class name="Item" identity-type="application"
objectid-class="com.lego.data.IntOId">
<extension vendor-name="kodo" key="table" value="item"/>
<extension vendor-name="kodo" key="lock-column" value="none"/>
<extension vendor-name="kodo" key="class-column" value="none"/>
<field name="item_id" primary-key="true">
<extension vendor-name="kodo" key="data-column" value="item_id"/>
</field>
<field name="item_number">
<extension vendor-name="kodo" key="data-column" value="item_number"/>
</field>
<field name="item_name">
<extension vendor-name="kodo" key="data-column" value="item_name"/>
</field>
<field name="theme_id">
<extension vendor-name="kodo" key="data-column" value="theme_id"/>
</field>
<field name="theme">
<extension vendor-name="kodo" key="theme_id-data-column"
value="theme_id"/>
</field>
</class>
<class name="Theme" identity-type="application"
objectid-class="com.lego.data.ThemeKey">
<extension vendor-name="kodo" key="table" value="theme"/>
<extension vendor-name="kodo" key="lock-column" value="none"/>
<extension vendor-name="kodo" key="class-column" value="none"/>
<field name="theme_id" primary-key="true">
<extension vendor-name="kodo" key="data-column" value="theme_id"/>
</field>
<field name="theme_description">
<extension vendor-name="kodo" key="data-column"
value="theme_description"/>
</field>
<field name="items">
<collection element-type="Item"/>
<extension vendor-name="kodo" key="inverse" value="theme"/>
</field>
</class>
</package>
</jdo>
Thanks in advance for the help.
-TimAbe White wrote:
The first thing to check is that you are always setting the "theme" field in
your Items. If you add an Item i to the "themes" collection of a Theme t, but
forget to also set i's "theme" field to t, then the change will never get
written to the database.
Next, make sure that whenever you set the "theme" field of an Item, you also
set
its "theme_id" field. You map both of these fields to the same column, so you
better be sure they stay in synch.
On a related note, you might try making the "theme_id" field non-persistent if
things still aren't working for you. Mapping two fields to the same column
might be causing trouble. It would be safer to make theme_id non-persistent
anyway, and to always grab the id from the Theme stored in your "theme"
field.
Better OO programming and all that, though I can see that you might have
performance issues in mind when doing it your way.
Anyway, if you find that it works when you make theme_id nonpersistent, let us
know and we'll see why the double-mapping of the column is causing problems,
and hopefully find a fix.Abe,
Thanks for the response but I'm still confused. I failed to mention that
the Item and Theme tables are in an existing schema, so as you saw in my
system.jdo, I am specifying application identity.
Since this is an existing schema, the Item table has theme_id as the
foreign key to the Theme table. So are saying that it is a problem to map
the both theme_id as a data column and a Theme object in the Item at the
same time?
I guess what I don't understand is exactly what my system.jdo should look
like to map a one-to-many relationship. In my case, from Theme (1) to Item
(many). (See my system.jdo in previous post).
Thanks
-Tim -
I'm a bit confused on how to create one to many relationships with ADF. Let's say I have a make and model table. One make can have many models. Now let's say I create a Business Facade like this (I'm using JavaBeans):
public Collection getMakes () { ... }
Ok, my data control now has the collection for makes. And I want to do something like this
public Collection getModels (Make make) { ... }
I can't make this work because ADF will detect it as a method accesor. How does this work?
Regards,
Néstor BoscánMaybe looking at how TopLink does it, can help you.
Try creating TopLink objects for a master detail set of tables (dept-emp).
This will create two beans that should be similar to your beans. Look at their structure to see how they work.
The ADF TopLink workshop has the steps to show you how to do this.
http://www.oracle.com/technology/obe/obe9051jdev/ide1012/adfworkshop/buildingadfapplicationsworkshop.htm -
Techniques to eliminate ripple loading in one to many relationships
Hi,
In my domain model, I have a class O that has a one to many relationship with class M. The relationship is mapped in TOPLink as a one to many from O to M, and a one to one from M to O.
An end user logs into our application that has an otherwise cold TOPLink cache and executes a use case that will render several to many aspects of each O instance, and there are many O instances to render a majority of the time.
The first time a question is asked of an O instance that requires its M instances to answer the question, TOPLink will detect the unstubbing of that ValueHolder, and cause a SQL query to pull in the necessary M instances for that O instance.
One technique to combat this ripple load is to mark the relationship between O and M to "useBatchReading". I am motivated to attempt a different technique in the particular scenario I am experiencing though.
Another technique would seem to be to fetch all of the M instances for all of the O instances to be rendered, compute the relevant Collection of M instances for each O instance and then call mValueHolder.setValue(readCollectionOfMs) on each O instance. Is this technique feasible? Seems like it doesn't align with the intent of the TOPLink API.
Are there any other techniques that can be used to solve this issue as well?
Thanks,
DougDoug,
What I believe you want is join and batch reading configured on the queries of your specific use case. That gives you much finer control then configuring these on the mappings.
With TopLink you should have your use cases issue a fixed quantity of SQL statements irrelevant of the # of objects returned from the root query.
Have you taken a look at the performance tuning chapter in the documentation?
I hope this helps,
Doug
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