I've an entity LearningUnit that has an int primary key. Actually, it has nothing more. Entity Concept has the following relationship with it: @ManyToOne @Size(min=1,max=7) private LearningUnit learningUnit; In a constructor of Concept I need to retrieve the LearningUnit with the greatest primary key. If no LearningUnit exists ...
Hi, Please consider the following table (created using a corresponding entity) request ------- id requestor type version items 1 a t1 1 5 2 a t1 2 3 3 b t1 1 2 4 a t2 1 4 5 a t1 3 9 The above is what I want to achieve. The version field is a c...
Ok, Here is my problem. I have a table named Master_Info_tbl. Its a lookup table: Here is the code for the table: @Entity @Table(name="MASTER_INFO_T") public class CodeValue implements java.io.Serializable { private static final long serialVersionUID = -3732397626260983394L; private Integer objectid; private String codetype; pr...
I expect every instantiated entity to correspond to a tuple (& co) in the database. In the examples I see around, one always instantiates the entity (via a constructor) and then calls persist with that entity. I find this error-prone, and was wondering if it wasn't possible to have every instantiated entity automatically managed/persiste...
Currently I have two tables in my database Encounters and Referrals: There is a one to many relationship between these two tables. Currently they are linked together with foreign keys. Right now I have public class Encounter extends JPASupport implements java.io.Serializable { @Column(name="referralid", unique=false, nulla...
I read in several places that JPA2 will support a detach method call on Entity Manager. I am running with Hibernate 3.5.1-FINAL and Spring 3.0.2-RELEASE as Maven dependencies -- snagged from the JBoss repository. Isn't this enough? Perhaps the problem is with my javax.persistence.EntityManager interface definition. Do I need to updat...
Does anyone have a good example for how to do a findByExample in JPA that will work within a generic DAO via reflection for any entity type? I know I can do it via my provider (Hibernate), but I don't want to break with neutrality... Seems like the criteria API might be the way to go....but I am not sure how to handle the reflection p...
Hai friends I have created two table as person and address using jpa. I want to give one to many relationship between these tables. if i give the folowing @OneToMany(mappedBy="address",targetEntity=person.class,fetch=FetchType.EAGER) in the address table means its not working correctly. cn any one help me. Thanks in advance. ...
Hi, I am creating entities that are the same for two different tables. In order do table mappings etc. different for the two entities but only have the rest of the code in one place - an abstract superclass. The best thing would be to be able to annotate generic stuff such as column names (since the will be identical) in the super clas...
GAE recommends using JDO/JPA. But I have serious question about using OODB like them. JDO based on user's class structure. And data structure should be modified continually as service advances. So, If data(entity) class property being removed, what happened to existing data on the property? If data(entity) class renamed for refactoring...
i am trying to set to jpa the new JDBC method which allows the application to be identified with a name it is the setClientInfo() and i could do it using pure JDBC using the lines Properties jdbcProperties = new Properties(); jdbcProperties.put("user", "system"); jdbcProperties.put("password", "sw01"); jdbcProperties.put("v$session.prog...
Hi There. Assume I have object which represents TASK. Task have due date. How do I create query to get all tasks which are due today? Some working code like "select t from Task t where dueDate=:today" will be usefull. Thank you in advance. ...
I just noted that my hibernate entities are automatically persisted to the database (or at least to cache) before I call any save() or update() method. To me this is a pretty strange default behavior but ok, as long as I can disable it, it´s fine. The problem I have is I want to update my entity´s state (from 1 to 2) only if the entity ...
A user may have several labels, and links. Then, a user associates a label (or more) to a link. How does one represent the later relationship? A solution could be a many-to-many relationship btw user and link with the optional attribute label. http://en.wikibooks.org/wiki/Java_Persistence/ManyToMany#Mapping_a_Join_Table_with_Additional_...
When I start my server and add an entry, the generated id will start with 1, 2, so on and so forth. After a restart, adding an entry would generate an id like 32,xxx. Another restart and adding of entry would generate an id like 65,xxx. I don't know why this is happening. Here's a snippet of the annotation I'm using for my id. I'm usin...
Consider the following entity class, used with, for example, EclipseLink 2.0.2 - where the link attribute is not the primary key, but unique nontheless. @Entity public class Profile { @Id private Long id; @Column(unique = true) private String link; // Some more attributes and getter and setter methods } When I insert re...
Why do I need to add allocationSize=1 when using the @TableGenerator to ensure that the id wouldn't jump from 1, 2,... to 32,xxx, 65,xxx,... after a jvm restart? Is there a design reason for the need to specify the allocationSize? This snippet would produce the jumping ids @Id @GeneratedValue(strategy = GenerationType.TABLE) private L...
What's the difference between @Basic(optional = false) and @Column(nullable = false) in JPA persistence??? ...
I have an entity (let's say Person) with a set of arbitrary attributes with a known subset of values. I need to search for all of these entities that match all my filter conditions. That is, given a set of Attributes A, I need to find all people that have a set of Attributes that are a superset of A. For example, my table structures loo...
hello everybody i am using JPA with EclipseLink and oracle as DB and i need to set the property v$session of jdbc4 it allows to set an identification name to the application for auditing purposes but i had no lucky setting it up....i have been trying through entitiyManager following the example in this page: http://wiki.eclipse.org/Conf...