in SqueakSafe (developed at HPI) they use traits exactly to be able to plug persistency in an existing domain single inheritance. Stef On Apr 8, 2010, at 9:02 AM, Friedrich Dominicus wrote:
Friedrich Dominicus <frido@q-software-solutions.de> writes:
I just wonder about experiences with non relational databases like e.g - Magma - Gemstone - others Ok to get a bit more concrete assume I have a simple inheritance as in the example
Object subclass: #ClosedFigure instanceVariableNames: 'sideA sideB sideC alpha beta gamma' classVariableNames: '' poolDictionaries: '' category: 'Pharo-Mailing-List-Example'!
!ClosedFigure methodsFor: 'as yet unclassified' stamp: 'FriedrichDominicus 4/8/2010 08:21'! area ^0 ! !
!ClosedFigure methodsFor: 'as yet unclassified' stamp: 'FriedrichDominicus 4/8/2010 07:07'! circumreference ^ 0! !
Object subclass: #ModelLine instanceVariableNames: 'length beginPoint endPoint' classVariableNames: '' poolDictionaries: '' category: 'Pharo-Mailing-List-Example'!
!ModelLine methodsFor: 'accessing' stamp: 'FriedrichDominicus 4/8/2010 07:09'! beginPoint ^ beginPoint! !
!ModelLine methodsFor: 'accessing' stamp: 'FriedrichDominicus 4/8/2010 07:09'! beginPoint: anObject beginPoint := anObject! !
!ModelLine methodsFor: 'accessing' stamp: 'FriedrichDominicus 4/8/2010 07:09'! endPoint ^ endPoint! !
!ModelLine methodsFor: 'accessing' stamp: 'FriedrichDominicus 4/8/2010 07:09'! endPoint: anObject endPoint := anObject! !
!ModelLine methodsFor: 'accessing' stamp: 'FriedrichDominicus 4/8/2010 07:09'! length ^ length! !
!ModelLine methodsFor: 'accessing' stamp: 'FriedrichDominicus 4/8/2010 07:09'! length: anObject length := anObject! !
!ModelLine methodsFor: 'as yet unclassified' stamp: 'FriedrichDominicus 4/8/2010 07:19'! initialize super initialize. length := 0.! !
"-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- "!
ModelLine class instanceVariableNames: ''!
!ModelLine class methodsFor: 'as yet unclassified' stamp: 'FriedrichDominicus 4/8/2010 07:33'! new: initialLength ^ self new length: initialLength ! !
ClosedFigure subclass: #ModelRectangle instanceVariableNames: 'lengthSideA lengthSideB' classVariableNames: '' poolDictionaries: '' category: 'Pharo-Mailing-List-Example'!
!ModelRectangle methodsFor: 'accessing' stamp: 'FriedrichDominicus 4/8/2010 08:31'! lengthSideA ^ lengthSideA! !
!ModelRectangle methodsFor: 'accessing' stamp: 'FriedrichDominicus 4/8/2010 08:31'! lengthSideA: anObject lengthSideA := anObject! !
!ModelRectangle methodsFor: 'accessing' stamp: 'FriedrichDominicus 4/8/2010 08:31'! lengthSideB ^ lengthSideB! !
!ModelRectangle methodsFor: 'accessing' stamp: 'FriedrichDominicus 4/8/2010 08:31'! lengthSideB: anObject lengthSideB := anObject! !
!ModelRectangle methodsFor: 'as yet unclassified' stamp: 'FriedrichDominicus 4/8/2010 08:35'! area ^ lengthSideA * lengthSideB ! !
!ModelRectangle methodsFor: 'as yet unclassified' stamp: 'FriedrichDominicus 4/8/2010 08:32'! lengthSideA: lenA lengthSideB: lenB super initialize. lengthSideA := lenA. lengthSideB := lenB.! !
"-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- "!
ModelRectangle class instanceVariableNames: ''!
!ModelRectangle class methodsFor: 'as yet unclassified' stamp: 'FriedrichDominicus 4/8/2010 08:39'! lengthSideA: lenA lengthSideB: lenB ^ self new lengthSideA: lenA lengthSideB: lenB.! !
ClosedFigure subclass: #ModelTriangle instanceVariableNames: 'height length' classVariableNames: '' poolDictionaries: '' category: 'Pharo-Mailing-List-Example'!
!ModelTriangle methodsFor: 'accessing' stamp: 'FriedrichDominicus 4/8/2010 08:51'! area ^ 1/2 * length * height ! !
!ModelTriangle methodsFor: 'accessing' stamp: 'FriedrichDominicus 4/8/2010 08:46'! height ^ height! !
!ModelTriangle methodsFor: 'accessing' stamp: 'FriedrichDominicus 4/8/2010 08:46'! height: anObject height := anObject! !
!ModelTriangle methodsFor: 'accessing' stamp: 'FriedrichDominicus 4/8/2010 08:46'! length ^ length! !
!ModelTriangle methodsFor: 'accessing' stamp: 'FriedrichDominicus 4/8/2010 08:46'! length: anObject length := anObject! !
!ModelTriangle methodsFor: 'as yet unclassified' stamp: 'FriedrichDominicus 4/8/2010 08:47'! length: aLength height: aHeight super initialize. length := aLength. height:= aHeight. ! !
"-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- "!
ModelTriangle class instanceVariableNames: ''!
!ModelTriangle class methodsFor: 'as yet unclassified' stamp: 'FriedrichDominicus 4/8/2010 08:49'! length: aLength height: aHeight ^ self new length: aLength height: aHeight.! !
Now this is as simple as can be. I have a Parent and two derived classes. How would I make this stuff persistent, and how would it look in different persistence solutions.
Let us assume. I would store the outline e.g in an OrderedCollection of Lines or whatever. What about other "ClosedFigures" like e.g circles, ellipses etc. How do I model inheritance in the diverse OR mappers. How does that work in let's say - Magma - Glorp - GemStone - whatever you choose
How would I query the database on let's side length of some lines of the Closed Figure, or let's say I like to query a few closed figures on their circumreference or area.
Or asked anotherway. How is inheritance handled in the diverse persistence tools..
Another question is how easy or difficult is it to have let's say something like a person with addresses, phone numbers etc.
How would I have to query let's say the street address of a certain Person. e.g
Regards Friedrich
-- Q-Software Solutions GmbH; Sitz: Bruchsal; Registergericht: Mannheim Registriernummer: HRB232138; Geschaeftsfuehrer: Friedrich Dominicus
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