DataView doesn't support multiple tables

[Sam Halliday]

Dear all,

DataViews appear to be limited to just one underlying DataTable. It would be useful to be able to combine multiple tables (which should have the same number of rows) in a DataView.

[ChartMan]

Thanks for the feedback.

On Fri, Dec 30, 2011 at 2:40 AM, Sam Halliday <sam.ha...@gmail.com> wrote:

Dear all,

DataViews appear to be limited to just one underlying DataTable. It would be useful to be able to combine multiple tables (which should have the same number of rows) in a DataView.

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[asgallant]

This is an interesting idea, but it could result in performance problems as you'd have to perform a join operation on the DataTables every time data in one or the other changes.

Perhaps I'm reading too much into the "same number of rows" comment, but if you have two DataTables that have a one-to-one relationship, why not make them one, single, table?

[Sam Halliday]

I originally had one big table and added lots of extra columns into it. But when I started experimenting with roles, the number of columns and the indexing became ludicrous. So I started using DataViews instead to create views of different aspects of the data: e.g. my own interpolated data, my own transformations to get the visuals to look right, etc. This brought its own problems, I've shared some of them on the list here.

However, when I created several views I was left in the position that I needed to create a DataTable again anyway. *sigh* Well performance isn't an issue at this stage but it just didn't feel elegant.

When I'm finished this project, I'll likely share my experiences with the group and some of my workaround codes. Overall, GViz has been a wonderful library to work with, but I feel I'm pushing it to its limits with my requirements! :-)