Primitive type or Object wrapper in CMP fields

peterwarde May 6, 2003 9:53 AM

Can anyone explain the design and performance issues and any other in having a CMP field on an entity bean as a primitive type or an object type such as a wrapper.

For example a field can be either an int or an Integer and both create an int 4 type in the database(Postgres) table when loaded into the container. However the primitive seems to be a NOT NULL contraint while the Integer allows nulls.

Can anyone help with the following

- Is this correct for all db's or just Postgres?

- If so is it a good design pratice to define sql tables as allowing NULL and NOT NULL using Integer and int declarations on entity bean fields ( as opposed to doing this directly in SQL)

- Are there any performance or other issues

Thanks

Peter

1. Re: Primitive type or Object wrapper in CMP fields

juhalindfors May 6, 2003 7:25 PM (in response to peterwarde)

> - Is this correct for all db's or just Postgres?

All DBs, this is a property of the DB type mappings.

> - If so is it a good design pratice to define sql
> tables as allowing NULL and NOT NULL using Integer
> and int declarations on entity bean fields ( as
> opposed to doing this directly in SQL)

There is no meaningful value for a primitive int if NULL is present in the column, an Integer field can contain a null reference I guess.

> - Are there any performance or other issues

Performance different would be insignificant.
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