Hi Tom,
thanks for your changes. I looks like you added my version of class
ParseTree in your jar, but I was able to adapt the class following your
changes in EJBQLParseTree.
Attached you find my EJBQL compiler changes of today. Together with your
changes a lot more queries work now. I also changed to always create a
ReportQuery as you proposed in the other email.
Please have a look at class SelectNode methods getReferenceClass,
resolveClass and resolveBaseClass. I tried to always use the class of
the first abstract schema in the FROM clause as the reference class.
Then getReferenceClass would return this class, resolveClass would call
getReferenceClass and resolveBaseClass would go away. But this runs into
a SQLException at runtime for a EJBQL query selecting a JOIN variable:
SELECT c FROM Order o JOIN o.customer c.
The generated SQL uses the table name CMP3_CUSTOMER instead the defined
table alias in the WHERE clause:
SELECT t0.ORDER_ID, t0.SHIP_ADDR, t0.CREATION_DATE, t0.TOTAL_PRICE,
t0.ORDER_VERSION, t0.QUANTITY, t0.ITEM_ID, t0.CUST_ID
FROM CMP3_ORDER t0, CMP3_ORDER t1
WHERE (CMP3_CUSTOMER.CUST_ID (+) = t1.CUST_ID)
The problem is the table qualifier in the WHERE clause, it uses
CMP3_CUSTOMER instead of t0.
The version in the attachment implements the above behavior, but still
has the old code in comments. Maybe you have an idea.
Thanks!
Regards Michael
> Michael,
>
> I have made progress on this issue. My current solution makes use of
> parts of the current framework that deal with parallel expression
> builders. Specifically, GenerationContext holds a list of the
> expressions we have built. I am testing some changes to EJBQLParseTree
> that appear to help. Essentially, I use the same GenerationContext for
> the whole query rather than rebuilding a new one for each operation.
>
> I am attaching my changes to the classes you sent me yesterday. Some
> more work may be needed, but I definitely get a better result. (two
> classes are changed - ParseTree and EJBQLParseTree)
>
> -Tom
>
> Tom Ware wrote:
>
>> Michael,
>>
>> I am still looking at your code, but I have noticed an issue that may
>> be causing your issue with multiple versions of the same table in the
>> where clause when you are building queries.
>>
>> The constructor ExpressionBuilder(Class) is special, it creates a
>> special parallel expression builder. Each time one of these is built,
>> it will result in a new reference to the table it refers to in the
>> where clause. Except in complex queries (for instance, certain
>> subselect queries), you likely want to refer to the same table. To do
>> that, use the same instance of the ExpressionBuilder. You may need to
>> maintain a list of the expression builders you have created.
>>
>> I am still working on getting you answers to your questions, but
>> wanted to send this information ASAP.
>>
>> -Tom
>>
>