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@GeneratedValue(strategy=GenerationType.AUTO) [message #692531]

Mon, 04 July 2011 16:58

Juergen Kissner

Messages: 25
Registered: March 2011

Junior Member

I have been playing with @GeneratedValue(strategy=GenerationType.AUTO) on various database platforms.

The HowTo on primary key generation (wiki.eclipse.org/EclipseLink/Examples/JPA/PrimaryKey) says:
"Typically, EclipseLink picks TABLE as the strategy, since it is the most portable strategy."

The adverb "Typically" seems to indicate that the strategy EclipseLink picks for GenerationType.AUTO can be configured.

Is there a way to influence EclipseLink's choice in such a way that the strategy for GenerationType.AUTO depends on the selected database platform?

--Juergen

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Re: @GeneratedValue(strategy=GenerationType.AUTO) [message #698461 is a reply to message #692531]

Tue, 19 July 2011 14:18

James Sutherland

Messages: 1939
Registered: July 2009
Location: Ottawa, Canada

Senior Member

EclipseLink defines a Map of Sequence objects on the EclipseLink Session's DatabaseLogin.

The login defines a DefaultSequence which could be set using a SessionCustomizer, or in your DatabasePlatform's initialization.
I think JPA AUTO will use a Sequence named "SEQ_GEN" by default, so you could define a Sequence with this name.
There is also a method in DatabasePlatform createPlatformDefaultSequence(), which you could potentially override to default to another type of sequencing.

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