Mapping a Boolean

Yeroc · **Joined:** Tue Mar 15, 2005 1:38 pm **Posts:** 11

Hello EJB3 gurus...

Can anyone tell me how I go about mapping a Boolean field in an EJB3 CMP entity bean? I'm trying to map to a database column that's CHAR(1) containing Y/N/null. As far as I can tell the EJB3 spec doesn't address this. Hibernate allows the developer to specify a strategy for mapping object types like this but how do I do this within the EJB3 standard? This seems like something so ridiculously common that I must be missing something?

Thanks,
Corey

alesj · **Posted:** Thu Nov 17, 2005 6:06 am

Quote:

4.4.5. Query Language Substitution

You may define new Hibernate query tokens using hibernate.query.substitutions. For example:

hibernate.query.substitutions true=1, false=0

would cause the tokens true and false to be translated to integer literals in the generated SQL.

Set this in the H3 properties.
Then in the db you simply have the smallest integer type (byte?) and in your code normal boolean property.

emmanuel · **Posted:** Thu Nov 17, 2005 8:41 am

That'd be cool if you EJB3 guys try not to crosspost against JBoss EJB3 forum and this one, this is really a PITA.

Yeroc · **Joined:** Tue Mar 15, 2005 1:38 pm **Posts:** 11

alesj,

I was looking for something within the EJB3 spec. I take it then, it's not possible? Please not also, I need to map Boolean to Y/N/null not 1/0. These are legacy tables I'm working with.

Thanks,
Corey

alesj wrote:

Quote:

4.4.5. Query Language Substitution

You may define new Hibernate query tokens using hibernate.query.substitutions. For example:

hibernate.query.substitutions true=1, false=0

would cause the tokens true and false to be translated to integer literals in the generated SQL.

Set this in the H3 properties.
Then in the db you simply have the smallest integer type (byte?) and in your code normal boolean property.

Yeroc · **Joined:** Tue Mar 15, 2005 1:38 pm **Posts:** 11

Emmanual,

I apologize for crossposting. Have you guys considered consolidating the EJB3 forums? It wasn't clear to me that the same experts inhabit both forums. Is one more appropriate than the other?

Corey

alesj · **Posted:** Thu Nov 17, 2005 11:52 am

Yeroc wrote:

I need to map Boolean to Y/N/null not 1/0. These are legacy tables I'm working with.

It's the same, use y == 1 and N == 0.
What to use for null?

Yeroc · **Joined:** Tue Mar 15, 2005 1:38 pm **Posts:** 11

As far as I can tell from the documentation using query substition is only going to work for querying, not for persisting.

Emmanual replied to my posting on the JBoss ejb3 forum saying that the way to do this is to use the Hibernate-specific @Type(type="yes_no") annotation. It appears this is not addressed by the EJB3 spec in any way. :(

Corey

emmanuel · **Posted:** Fri Nov 18, 2005 8:10 am

This forum is better for people understanding Hibernate from the ground and wanting to switch.
The other one is better for pure EJB3 players from the ground.