Re: [Springframework-developer] New JDBC feature - named parameters

[James E. <jam...@gm...>]

http://opensource2.atlassian.com/projects/spring/browse/SPR-303

Hey Thomas, I'm glad to see this getting some traction.  I have a few
questions though.

Will the implementation support pulling the values from a bean (where
the names in the query match property names in the bean)?  The
original argument against was to just use ibatis...but with what you
have it is so close.  I'd probably need to (for the most part) map my
bean to and from a hashmap for the execute calls.

I'm going to be looking at the code soon, but my first reaction to the
auto-expanding list was one of fear.  I'm sure it has been implemented
optimally, but just to voice my fear:  does passing in a list as a
value simply trigger a replacement of that value/marker with a comma
separated list of other markers (?s)?  Or is it one that will replace
the marker with a comma-separated list of the values.  If it is the
former, the hit is not too bad...assuming most use cases are such that
only a set number or combination winds up getting used (like between 3
and 10).  And (in the case of Oracle) only that many statements are
cached and all is well.  But if its the latter (replaced with
comma-separated values) then every single call is unique...and the db=20
(oracle anyway) will die (especially if this call is made frequently)
because the statement cache will constantly be pushing out statements
for these new ones that appear to be unique.

Anyway I hope I'm not insulting you...I'm sure you know this, like I
said, just voicing my initial gut-fear.

Thanks again Thomas,
James

On 9/7/05, Thomas Risberg <tho...@tr...> wrote:
> I added support for named parameters some days ago.  Here is an example: =
  =20
>                                                    =20
>=20
>    public List getPreferredBeer() {
>     Map params =3D new HashMap(2);
>     params.put("unwantedBrand", "Heineken");
>     params.put("maxPrice", new BigDecimal(25.00));
>     List l =3D getJdbcTemplate().queryForList(
>       "select id, price, brand from beers " +
>       "where price < :maxPrice and brand <> :unwantedBrand",
>       params);
>     return l;
>   }
>=20
> I put together a PDF document that highlights additional usage -
> http://www.springdeveloper.com/documents/spring-1_3-jdbc-example.pdf
>=20
> Take a recent snapshot for a spin and let me know if something is missing=
 or
> not working.  I'm still working on adding some additional tests.
>=20
> Thomas
>=20
>