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How to not reinialize tables created with JPA?

Siegfried Heintze
Ranch Hand

Joined: Aug 11, 2000
Posts: 388
This example seems to work: http://javahowto.blogspot.com/2006/07/helloworld-with-jpa-toplink-and-mysql.html

However, when I comment out the statements that create and delete the objects (as I have done below), I expect to see it display the same greetings and messages. Instead, no messages are being retrieved. Apparently something is recreating the database tables every time I run the program. What do change so I can run this program and see the data previously entered into the database?

Thanks,
Siegfried

HelloWorld.java:


Greeting.java:


Message.java:
Vesa Tanhua-Tyrkk�
Greenhorn

Joined: Jan 16, 2008
Posts: 25
Hi,

This is configured in persistence.xml by property:
<property name="toplink.ddl-generation" value="drop-and-create-tables"/>

possible values for this are create-tables, drop-and-create-tables,none

So I think that by removing that property form persistence.xml preserves your data.
 
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