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java persistence-Help

 
sree visu
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As i am new to hibernate,i would like to know what is java persistence.I made a lot of search but it provides some complex explanations which i could not understand.

i am new both to EJB's and hibernate and i have knowledge of JDBC.Also is it necessary to have a knowledge of EJB before learning Hibernate?If so which version to learn EJB 2.x or EJB 3.o

please clarify my doubts.Thanks in advance
 
Akhilesh Trivedi
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Ask yourself these questions,
what is a class?
what is an object?
what do they mean when they say java is object oriented?
why an 'user' class extends 'person' class and not 'animal' class?
what is serialization why do we need it?
What are relations in database?
why there is an 'employee_details' table that looks like or is completely similar to my 'employee' class?
 
Paul Sturrock
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Eclipse IDE Hibernate Java
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This may be one of the links you've already read, but this is the problem ORM exists to solve.
 
sree visu
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Thanks for both of your reply.I could understand the Object relational impedance mismatch.But i am really sorry to ask this question again as i basically do not understand the word "persistence" and what is java persistence.

Thanks for your reply in advance
 
Paul Sturrock
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To persist something is to put it into some sort of long term store that outlives the lifetime of the application an object belongs to. For example, if you Serialize an object to disk you are making it persisent. In the context of ORMs the long term store you are using is a relational database, so you "persist" an object to the database.
 
sree visu
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Thank you Paul Sturrock. I could now understand it.Thanks a lot
 
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