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From Craig Russell <Craig.Russ...@Sun.COM>
Subject Re: Binding a char to PreparedStatement
Date Wed, 20 Jul 2005 17:05:36 GMT
Hi Andy,

On Jul 20, 2005, at 9:57 AM, Andy Jefferson wrote:

>>> Well in the case of a char it is, but in the case of a java  
>>> double for
>>> example ? It all depends on the RDBMS. Some RDBMS support DOUBLE,  
>>> some
>>> DECIMAL, some NUMERIC, some have other types ...
>> This is the jdbc-type ("generic sql type"), not the sql-type we're
>> talking about (there is a separate sql-type that the user can specify
>> if they want to get database specific).
>> The idea is that the user could override the jdbc-type if necessary,
>> and the jdo impl would use jdbc-type plus length plus nullability to
>> map to a natural sql-type that is database specific.
> I'm also talking about the jdbc-type (or to be specific  
> javax.sql.Types). So
> the JDO impl should always take JDBC Types.DOUBLE when the user has  
> a Java
> double field? Many JDBC drivers *don't* provide a type mapping for
> Types.DOUBLE (many don't provide support for several of the  
> "standard" JDBC
> types).

I'm trying to see where the confusion is. The attribute is only  
specified if the user wants to override the default for the field  
type. Is this what you're talking about?

> We've always encouraged our users to specify the jdbc-type if they  
> want things
> to be JDO-impl independent for this very reason.

Right, so your users just want to specify the database specific type  
because they know what kind of database they are using.
> While a default may make sense so people know what they get if  
> nothing is
> specified, there are *a lot* of situations where the JDBC driver  
> doesnt
> support a "generic" sql type even

Where does this give you trouble?


> -- 
> Andy
> Java Persistent Objects - JPOX

Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:Craig.Russell@sun.com
P.S. A good JDO? O, Gasp!

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