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Hibernate OneToMany, natural PK

I've got problem with setting up OneToMany relationship.
My DB schema:
TABLE PARENT (
VENDOR,
CHANNEL,
CREATEDATE,
REFID,
...
)
UNIQUE INDEX PK_PARENT (VENDOR, CHANNEL, CREATEDATE, REFID)
TABLE CHILD (
REFID,
NAME,
)
UNIQUE INDEX PK_CHILD (REFID, NAME)
And Java class
public class Parent {
String vendor;
String channel;
Date createdate;
Long refid;
List<Child> childs;
...
}
public class Child {
Long refid;
String name;
}
My problem is that I can not develop proper mapping for this classes. For consistent reasons I'm forced to use hbm xml. I was able to map it as two separate entities.
<hibernate-mapping>
<class name="Parent" table="PARENT">
<composite-id >
<key-property name="vendor" type="string">
<column name="VENDOR" />
</key-property>
<key-property name="vendor" type="string">
<column name="CHANNEL" />
</key-property>
<key-property name="vendor" type="Date">
<column name="CREATEDATE" />
</key-property>
<key-property name="vendor" type="Long">
<column name="REFID" />
</key-property>
<composite-id />
<list name="childs" table="CHILD" lazy="true" fetch="select">
<key column="REFID" />
<index column="REFID" />
<one-to-many class="Child" />
</list>
</class>
<class name="Child" table="CHILD">
<composite-id >
<key-property name="vendor" type="Long">
<column name="REFID" />
</key-property>
<key-property name="name" type="string">
<column name="NAME" />
</key-property>
<composite-id />
</class>
</hibernate-mapping>
I get exception:
Caused by: org.hibernate.MappingException: Foreign key (FK_9897tr114hxkewktsi9vb92x6:CHILD[REFID])) must have same number of columns as the referenced primary key (PARENT[VENDOR,CHANNEL,CREATEDATE,REFID])
at org.hibernate.mapping.ForeignKey.alignColumns(ForeignKey.java:110)
at org.hibernate.mapping.ForeignKey.alignColumns(ForeignKey.java:93)
at org.hibernate.cfg.Configuration.secondPassCompileForeignKeys(Configuration.java:1818)
at org.hibernate.cfg.Configuration.originalSecondPassCompile(Configuration.java:1741)
at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1426)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1846)
at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1930)
Any thoughts on that?

Because your Child entity have a complex key, therefore in the Parent entity you need specify foreign key as complex also.

Change the property names according to java class fields in your hibernate configuration xml file. If you have a "channel" field in your java class, then it should be named as "channel" in your hbm configuration although it is a part of composite primary key.
<class name="Parent" table="PARENT">
<composite-id >
<key-property name="vendor" type="string">
<column name="VENDOR" />
</key-property>
<key-property name="channel" type="string">
<column name="CHANNEL" />
</key-property>
<key-property name="createdate" type="Date">
<column name="CREATEDATE" />
</key-property>
<key-property name="refid" type="Long">
<column name="REFID" />
</key-property>
<composite-id />
<list name="childs" table="CHILD" lazy="true" fetch="select">
<key column="REFID" />
<index column="REFID" />
<one-to-many class="Child" />
</list>
Also, you should define manyToOne relationship in the other side of mapping. And there can be a Parent instance in the child class properly.(Not just an ID)

How can I fix "object references an unsaved transient instance - save the transient instance before flushing" on a large project?

I downloaded and installed the source code for the Perseus Project (Open Source Code) on to Ubuntu 14.04, and Tomcat 6. The project hasn't been modified in years, so it must be some new feature in hibernate that is doing this.
I see the solutions here on very many threads, but they address the issue of debugging code as it is being written as opposed to migrating a project that quite certainly worked "at one time". The code that I am working with hasn't been modified since 2008-2011. (I've determined that they are running it now on "Mandriva Linux 2010.2") Therefore, I need to be able to fix this issue on a large scale - either a search/replace method or a configuration file change. I have never used hibernate myself, so I don't understand the full meaning of the posted answers.
Thanks.
Also, the files don't use the # annotated syntax, but the mappings seem to be done via XML files. At this point, I would not mind just to update all these files if I knew what to change.
<?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 package="perseus.document.dao">
<class name="HibernateChunkDAO$ChunkRow" table="hib_chunks" batch-size="10">
<id name="id" type="int" column="id" unsaved-value="null">
<generator class="native" />
</id>
<property name="documentID" column="document_id" type="string"
length="50" index="doc_idx doc_type_idx doc_type_value_idx
doc_cid_idx doc_so_eo_idx doc_so_eo_type_idx doc_dq_idx
doc_so_eo_type_val_idx" />
<property name="elementName" column="element" type="string"
length="20" />
<property name="type" column="type" type="string" length="30"
index="doc_type_idx doc_type_value_idx doc_so_eo_type_idx
doc_so_eo_type_val_idx" />
<property name="value" column="value" type="string" length="250"
index="doc_type_value_idx doc_so_eo_type_val_idx" />
<property name="position" column="position" type="int" />
<property name="absolutePosition" column="abs_position" type="int" />
<property name="chunkID" column="chunk_id" type="string"
length="255" index="doc_cid_idx" />
<property name="openTags" column="open_tags" type="text" />
<property name="closeTags" column="close_tags" type="text" />
<property name="startOffset" column="start_offset" type="int"
index="doc_so_eo_idx doc_so_eo_type_idx doc_so_eo_type_val_idx" />
<property name="endOffset" column="end_offset" type="int"
index="doc_so_eo_idx doc_so_eo_type_idx doc_so_eo_type_val_idx" />
<property name="displayQuery" column="display_query" type="string"
length="100" index="doc_dq_idx" />
<property name="head" column="head" type="text" />
<property name="headLanguage" column="head_lang" type="string"
length="10" />
<property name="hasCustomHead" column="custom_head" type="boolean" />
<set name="frequencies" inverse="true" cascade="all-delete-orphan"
lazy="true" batch-size="30">
<key column="chunk_id" on-delete="cascade" />
<one-to-many class="perseus.ie.freq.Frequency" />
</set>
<many-to-one name="lemma" column="lemma_id" cascade="all" lazy="false" />
<!--
<list name="senses" inverse="false" cascade="all-delete-orphan"
lazy="false" batch-size="30">
<key column="chunk_id" />
<list-index column="position" />
<one-to-many class="perseus.voting.Sense" />
</list>
-->
</class>
</hibernate-mapping>

This is happening due to below reason:
You have defined a association in your entity which is not yet persisted in the database and before persisting this association you are trying to flush the Session.For example you have a collection association which has collection of transient instances, so you have to persist this collection first before flushing.
For resolving this issue, you have 2 options:
Either manually persist the collection in your code by calling Session.save() method.
If you want to use tags in Hibernate XML file or want to use annotations make use of cascade="all" (for xml) or cascade=CascadeType.ALL (for annotations) on your collection association.

How to map an auto increment field in hibernate?

Please have a look at the below XML code
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<!-- Generated Feb 17, 2015 10:01:43 PM by Hibernate Tools 4.3.1 -->
<hibernate-mapping>
<class name="model.main.Family" table="family" catalog="****" optimistic-lock="version">
<id name="idFamily" type="int">
<column name="idFamily" />
<generator class="assigned" />
</id>
<many-to-one name="employee" class="model.main.Employee" fetch="select">
<column name="idEmployee" not-null="true" />
</many-to-one>
<property name="firstName" type="string">
<column name="FirstName" length="45" />
</property>
<property name="middleName" type="string">
<column name="MiddleName" length="45" />
</property>
<property name="lastName" type="string">
<column name="LastName" length="45" />
</property>
<property name="dob" type="date">
<column name="DOB" length="10" />
</property>
<property name="passportNumber" type="string">
<column name="PassportNumber" length="45" not-null="true" />
</property>
<property name="dateLeft" type="date">
<column name="DateLeft" length="10" />
</property>
<property name="lastUpdated" type="timestamp">
<column name="LastUpdated" length="19" not-null="true" />
</property>
<set name="visas" table="visa" inverse="true" lazy="true" fetch="select">
<key>
<column name="idFamily" />
</key>
<one-to-many class="model.main.Visa" />
</set>
</class>
</hibernate-mapping>
It is the Hibernate mapping class of my database table Family. We create the database separately using MySQL Work bench and then generate the mapping classes. We auto generated the mapping files using netbeans as mentioned in "Generating Hibernate Mapping Files and Java Classes" section of netbeans tutorial.
Now we have a problem. That is, we changed the primary key (idFamily) of our table Family to an auto generated field inside MySQL. Now, how can we change the above hibernate code so it identifies the idFamily as an auto generated one?
The other question is, manually editing one mapping class without regenerating all the mappings via a tool can "break" the system? For an example, like messing up with relationships?

In Annotation It work for me as
#GeneratedValue(strategy= GenerationType.IDENTITY)
for you hope it works
<generated-value strategy="IDENTITY" />

You're looking for an identity column. That indicates that the column value is auto-generated as an identity for the row by the RDBMS.
<generator class="identity" />
See the these Hibernate docs for more information. According to it:
Identity
supports identity columns in DB2, MySQL, MS SQL Server, Sybase and HypersonicSQL. The returned identifier is of type long, short or int.

Just replace your generator class to increment it will treat it as autoincrement
<generator class="increment"/>

<?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="com.tech.spring4.model.User" table="Customer">
<id name="id" type="long">
<column name="USERID" unique="true"/>
<generator class="increment"/>
</id>
<property name="username"><column name="username" length="30" not-null="true"></column></property>
<property name="email"><column name="email" length="100" not-null="true"></column></property>
<property name="address"><column name="address" length="100" not-null="true"></column></property>
</class>
</hibernate-mapping>

How to tell Hibernate to not Load a Object?

Hello Stackeroverflowers,
i'd like to ask how i can solve the following problem:
I have 3 Tables:
Hardware
PC
Software
They have a Many-to-Many Relation. So N Hardware Entries can have M Hardware Entries.
When im Calling my Hibernate stuff then i get all Pc's with the chosen Software. In Software i have a Mappign on Hardware to get the specified Hardware of a Pc.
So far so good.
The Problem im facing is that i have to make this compatible from the other side to allow to get all Pc's with the specified Hardware and then from the Pc's the software.
When i have a mapping that links from Software over Pc to Hardware its ok. When i put a mapping into Hardware to get Pc's. Im getting a Stackoverflow because Hibernate tries to create everytime i initialize a Hardware to initialize a Pc and Pc tries then to initialize a Hardware so i get a Loop that never ends.
Can someone give me a hint to Solve this problem ?
I heard of that the attribute inverse can solve this but i dont know where ro place it and how it works.
I'm thankful for every Comment.
Hardware.hbm.xml
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 04.11.2013 17:30:12 by Hibernate Tools 3.4.0.CR1 -->
<hibernate-mapping>
<class name="de.test.database.pojo.Hardware" table="object" schema="XXX">
<id name="id" type="int">
<column name="id" />
<generator class="assigned" />
</id>
<property name="fkserialId" type="int">
<column name="fk_serial_id" not-null="true" />
</property>
<property name="name" type="string">
<column name="name_id" not-null="true" />
</property>
<set name="linkHardwareToSoftware" table="pc_link" inverse="true" lazy="true" fetch="select">
<key foreign-key="none">
<column name="fk_serial_id" not-null="true" />
</key>
<one-to-many class="de.test.database.pojo.PC" />
</set>
</class>
</hibernate-mapping>
PC.hbm.xml
<hibernate-mapping>
<class name="de.test.database.pojo.pc" table="pc_link" schema="xxx">
<id name="id" type="int">
<column name="id" />
<generator class="assigned" />
</id>
<property name="sort" type="int">
<column name="sort" not-null="true" />
</property>
<property name="owner" type="string">
<column name="owner" not-null="true" />
</property>
<many-to-one name="hardware" class="de.test.database.pojo.hardware" fetch="select">
<column name="fk_serial_id" not-null="true" />
</many-to-one>
<many-to-one name="software" class="de.test.database.pojo.Software" fetch="select">
<column name="fk_sw_id" not-null="true" />
</many-to-one>
</class>
</hibernate-mapping>
Software.hbm.xml
<hibernate-mapping>
<class name="de.test.database.pojo.Software" table="object" schema="xxx">
<id name="id" type="int">
<column name="id" />
<generator class="assigned" />
</id>
<property name="fkswId" type="int">
<column name="fk_sw_id" not-null="true" />
</property>
<property name="name" type="java.lang.Integer">
<column name="name" />
</property>
<property name="company" type="java.lang.Integer">
<column name="company" />
</property>
<set name="linkSWToHardware" table="pc_link" inverse="true" lazy="true" fetch="select">
<key foreign-key="none">
<column name="fk_sw_id" not-null="true" />
</key>
<one-to-many class="de.test.database.pojo.pc" />
</set>
</class>
</hibernate-mapping>
HibernateCode.java
try
{
String obj =" AND t.fkHWtypeId =:otid";
if(objectType==0)
obj="";
Session ses = getSession();
Query query = ses.createQuery(
" FROM hardware t"+
" WHERE t.deleted = 0 AND t.Id =:pid"+obj
);
query.setParameter("pid", HardwareId);
if(objectType!=0){
System.out.println("Reading HWtypeid...");
query.setParameter("HWtypeid", HardwareType);
}
List<Tree> list = query.list();
return list;
} catch (HibernateException e)
{
return null;
}
Stacktrace:
org.codehaus.jackson.map.JsonMappingException: Infinite recursion (StackOverflowError) (through reference chain: de.test.database.pojo.Pc["hardware"]->de.test.database.pojo.Hardware_$$_javassist_109["linkHardwareToSoftware"]->org.hibernate.collection.internal.PersistentSet[0]->de.test.database.pojo.pc["object"]->de.test.database.pojo.Hardware_$$_javassist_109["linkHardwareToSoftware"]
at org.codehaus.jackson.map.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:164)
at org.codehaus.jackson.map.ser.BeanSerializer.serialize(BeanSerializer.java:112)
at org.codehaus.jackson.map.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:72)
at org.codehaus.jackson.map.ser.std.CollectionSerializer.serializeContents(CollectionSerializer.java:23)
at org.codehaus.jackson.map.ser.std.AsArraySerializerBase.serialize(AsArraySerializerBase.java:86)
at org.codehaus.jackson.map.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:446)
at org.codehaus.jackson.map.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:150)
at org.codehaus.jackson.map.ser.BeanSerializer.serialize(BeanSerializer.java:112)
at org.codehaus.jackson.map.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:446)
at org.codehaus.jackson.map.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:150)

As the stack trace indicates, the problem has nothing to do with the mapping and with loading data from the database with Hibernate. The problem happens when you're serializing your beans with Jackson, because you have bidirectional associations and thus cyclic references which cause Jackson to loop endlessly.
So, you should choose how you want to serialize your objects, and use Jackson annotations or use DTOs to serialize them and break the cycles between objects. You could, for example, add a #JsonIgnore on the linkHardwareToSoftware field, so that the collection of software is not serialized when serializing a Hardware instance.

How to set a null in the database for the integer field using hibernate?

I am trying to update a field in the database to null for an integer field. I am trying to do that using hibernate. I can set object field like String and any other object to null but no integer.
<?xml version="1.0" encoding="UTF-8"?>
<class name="App_Users" table="app_users" schema="bidtool">
<id name="userId" type="int" column="user_id">
<generator class="assigned"/>
</id>
<property name="username" type="string">
<column name="username" length="20" not-null="true" />
</property>
<property name="password" type="string">
<column name="password" length="20" not-null="true" />
</property>
<property name="firstname" type="string">
<column name="firstname" length="20" />
</property>
<property name="lastname" type="string">
<column name="lastname" length="20" />
</property>
<property name="userType" type="int">
<column name="user_type" />
</property>
<many-to-one class="MasterOrg" fetch="select" name="masterOrg">
<column name="master_org_id" />
</many-to-one>
<many-to-one class="CarrierScac" fetch="select" name="carrierScac">
<column name="scac" />
</many-to-one>
<one-to-one class="AppUserDetails" fetch="select" name="details" constrained="true"/>
<set name="profiles" inverse="true">
<key>
<column name="user_id" />
</key>
<one-to-many class="Profiles" />
</set>
<set name="boilerPlates" inverse="true">
<key>
<column name="user_id" />
</key>
<one-to-many class="BoilerPlate" />
</set>
<set name="rates" inverse="true" >
<key>
<column name="user_id" />
</key>
<one-to-many class="BidToolRates" />
</set>
</class>
In the above hibernate mapping code, I want to set MasterOrg field as null.

It is best to use the object wrappers for the primitive types i.e. Integer for int, Double for double, ... etc because primitive types don't allow for the possibility of null which is always possible in a database design.
Even if a value is declared not null in the database an Object type is still useful. Consider the follow scenario as an example.
#Entity
public class ExampleEntity {
#Column(name="some_column") // assume this column is defined not null in the database
private int someProperty;
getttes settters other fields go here
}
Assume you write the following code
ExampleEntity t = new ExampleEntity();
entityManager.persist(t);
In this example t.someProperty has a value of 0 because that is the default value for an int therefore entityManager.persist works but maybe 0 is not a valid value for that column. If you have database constraints on that column then you get an error otherwise you have bad data in the database.
If someProperty was declared with wrapper type of Integer and the developer forgets to set the somePorpety value then you will get a not null exception.
A second reason to always use wrappers is simplicity as a developer I want consistent structure across entities because code is read more often that it is written so universally using wrapper types on entities makes things predictable for some one maintaining the code 5 years from now.