Re: core data approach to multi-column data?
Re: core data approach to multi-column data?
- Subject: Re: core data approach to multi-column data?
- From: Jesse Grosjean <email@hidden>
- Date: Tue, 22 Aug 2006 16:50:17 -0400
I am trying to think about how (a) to design the core data entities,
and (b) how to link them easily to a view (e.g. NSTableView). One
idea is to have an entity called "row" which has a many-to-one
relationship to an entity called "column". Then each row of data can
have multiple columns. The question then is how to get an NSTableView
to be bound to display each "column" of data in its own column in the
NSTableView. Core data seems set up for more traditional database-
style apps where a row in an NSTableView is a single entity, and the
different columns are different attributes of that entity.
Any thoughts? The reason I'm thinking core data is pure laziness, the
file opening/saving, searching, and undo/redo comes basically for free
See this thread for info on designing the core data entities.
http://www.cocoabuilder.com/archive/message/cocoa/2006/1/3/153637
In my experience this sort of thing is difficult to model so that
it's efficient and easy to query. For my application I tried a number
of different approaches, but none were really satisfactory. In the
end the only approach that was fast enough was to hardcode the
columns as attributes in the row entity. That means that columns
can't change dynamically, but I deal with this by modifying the
managed object model, and then migrate the data to that new model...
a big pain, and a bit of a hack, but it work for my application where
columns need to change, but not very often.
Jesse
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