Dain Sundstrom wrote:
> Sorry for the confusion. There are two issues here.
>
> ==================================================
>
> Issue1: use of the {fn concat(str1, str2)} style functions.
>
> Solution: use fn style functions as default but have override in xml like:
> <concat-function>CONCAT (?1, ?2)</concat-function>
> or some thing simmilar.
>
> ==================================================
>
Since I have only used the PostgreSQL driver hard to say how other
vendors JDBC drivers are but have heard lots of comments about Oracle
.... I would suggest you try and code to the lowest JDBC version and
wrap up the strange bits in the xml (more jaws stuff). For example in
Postgresql, concat is || so ..
<concat-function>?1 || ?2</concat-function>
Looks like the way to go ... (Dam more work!)
> Issue 2: IS EMPTY function. How should I map the following ejb-ql query:
>
> SELECT OBJECT(o)
> FROM Order o
> WHERE o.lineItems IS EMPTY
>
> Solution A:
>
> SELECT o.ordernumber
> FROM Order o
> WHERE NOT EXISTS (
> SELECT l.pk
> FROM Order o, LineItem l
> WHERE o.ordernumber = l.ordernumber)
>
> I like this because it does not use an outer join (thanks Dave Smith). Does
> it have performance problems?
>
> Solution B:
>
> SELECT o.ordernumber
> FROM Order o LEFT OUTER JOIN LineItem l ON o.ordernumber = l.ordernumber
> WHERE l.ordernumber IS NULL
>
> This would be a major pain to map to all vendors.
>
>
Either way the query will have to read the entire order file to check
the lineitems . I would get it working first then optimize, might be
there but not offen used.
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