Am 14.03.2006 14:18 Uhr schrieb "Kieran Kelleher" unter
<[EMAIL PROTECTED]>:

Hello Kieran,


> I had issues with EOQualifiers and inheritance hierarchies generating
> bad SQL a few weeks ago and the solution (Chuck Hill responded I think)
> was to stick with single table inheritance if you want reliable SQL
> generated from your EOQualifiers.
This is not a too good advice for a productive application...
Shouldn't WO use EOQualifiers in producing it's own fetches, that work well
with vertical inheritance?

Thanks anyway :-)

Wolfram

>> i create a complex query from user input via EOKeyValueQualifier and
>> other
>> EOQualifiers.
>> 
>> Absolutely fine is:
>> EOKeyValueQualifier ( myAttributeName, mySelector, myComparedEO );
>> 
>> Also OK is it for a keypath to a non flattened attribute (lets say:
>> "location.derivedClassAttribute", where location is a derived class):
>> EOKeyValueQualifier ( "location.derivedClassAttribute", mySelector,
>> myComparedValue );
>> (myComparedValue is a string in this case).
>> 
>> The above statement creates joins with aliases like:
>> 
>> ...FetchedClass t0, Location T1, LocationBaseClass T2...
>> 
>> and fetches the correct EOs.
>> 
>> When the left hand side points to an attribute of an inherited class it
>> evaluates to the wrong derived entity:
>> Compared to the above example:
>> EOKeyValueQualifier ( "location.baseClassAttribute", mySelector,
>> myComparedValue );
>> does not evaluate to table "Location". Instead it creates aliases like:
>> 
>> ... FetchedClass t0, Person T1, LocationBaseClass T2...
>> 
>> where "Person" is another derived class of the same base class.
>> 
>> This seems to be a bug, because the class information for
>> "location.baseClassAttribute" is available and correct for the relation
>> "location", but it does not create the correct SQL.


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