[Pharo-users] Glorp: #includesKey:

jtuchel at objektfabrik.de jtuchel at objektfabrik.de
Wed Oct 25 00:13:28 EDT 2017


Herby,

I must admit I've never used Dictionary Mappings with Glorp, so I don't 
have an answer.
But I am a bit confused by your code examples. See below


Am 24.10.17 um 20:27 schrieb Herby Vojčík:
> Hello!
>
> I am using a DictionaryMapping in my code, and I wanted to use 
> #includesKey: in #where: clause (something akin
>
>   each tools includesKey: aToolId

What SQL expression would you expect here?

I would guess that you want to build a subquery like exists, because the 
way I understand the query, you want to find all instances of (whatever 
each is) that hold an Association in their tools dictionary where the 
key is aToolId.
>
> ) to select only rows for which DictionaryMapping uses certain key. It 
> failed with the error in the lines of "#tools does not resolve to 
> field". I had to come up with
>

> each tools anySatisfy: [ :tool | tool id = aToolId ]
Hmm. This makes me wonder. Is #tools really a Dictionary? Inside the 
Block, I'd expect the :tool parameter to be an Association, and that 
doesn't understand #id,does it? I guess @each is the parameter within an 
Block like in

self session read: MyClass where: [:each| each tools ...]

If so, I have a hard time believing that anySatisfy: would work (never 
tried)...


>
>
> Is it the bug / feature / problem in my approach? If bug, is it 
> planned to add #includesKey: translation to DictionaryMapping?
>
I don't know, but would guess it is not currently on the Todo-list.

My first tip would be to try and find some slides (most likely made by 
Niall and presented at an ESUG) including the words "subquery", "glorp" 
and "exists". You won't find much, but that may be a starting point.

Not sure this helps, ;-)


Joachim


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