Add a bottom row that aggregates each metric column for table viz

[yxjames]

In table viz, I add a table footer that shows the sum of metric columns.
The footer can't be sorted to the top.

[xrmx]

There's something off there as tests fails :)

[coveralls]

Coverage increased (+0.04%) to 81.276% when pulling efd86c8 on joshwalters:sum_table_viz into 198226a on airbnb:master.

[coveralls]

Coverage increased (+0.04%) to 81.276% when pulling efd86c8 on joshwalters:sum_table_viz into 198226a on airbnb:master.

[kkalyan]

Thanks @yxjames for addressing #832

[mistercrunch]

Sorry this never made it in, I'm cleaning up older PRs with merge conflicts at the moment. Please resubmit the PR if you want this feature to make it in.

[tristix]

+1 for anyone knowledgeable enough to get this in!

[apelliciari]

+1 this is a nobrain for a data viz tool

[Geoiv]

This is an old PR at this point, but still +1 to the idea. I'm looking through the project to see about implementing it myself, but I may not be knowledgeable enough on the internals of Superset to do so.

[villebro]

This is a good idea, but I don't think it can be solved on the client side as proposed in this PR, as metrics need to be aggregated on the datasource (think mean, weighted average or other custom aggregation which can't simply be summed up). However, by leveraging the new chart API, this could be done fairly elegantly by issuing two queries in the QueryContext; one for the regular grouped row-by-row results, and a second one with the same metrics, but without grouping, which is displayed at the bottom. Could be an interesting POC.

[bkarlson]

+1 was shocked to discover this cannot be done.. I sure can add rollup to my query, but the bottom row won't be fixed and won't be rendered bold, bad UX..

[Northern125]

+1, good idea, and a very much needed feature.