Fixing value name. Adding updates

[antoniocarlon]

Fixing value name (per_sq_km)
Adding UPDATE queries

Closes #310

[javitonino]

Left a comment about the column name.

Aside from that, I would prefer to put the UPDATE query before the SELECT one. We prefer clients to use UPDATE (less hits to the DO database) so let's make it more visible if you agree.

[javitonino]

Uhm, I'm not sure if it's available in the RSTs, but the optimal solution would be to use the same column name we autogenerate for Builder, i.e: the suggested_name column of the GetMeta result.

If not, we can probably add it to the query to generate rsts, or replicate this logic in python:
https://github.com/CartoDB/observatory-extension/blob/develop/src/pg/sql/41_observatory_augmentation.sql#L249-L257

[antoniocarlon]

Putting the UPDATE before the SELECT was my first idea because nobody needs to only see the data but do something with it. I leaved the SELECT first to be more conservative and trying not to surprise the user but it's clear that we agree that putting the UPDATEs first is more natural so I'm changing it.

[javitonino]

Code looks nice, let's see how it works!

[javitonino]

For reference, this is how this looks:

Some questions/suggestions:

• For updating a table, the WITH data part should probably take data from a table, something like:

WITH data AS (
  SELECT cartodb_id as id, the_geom FROM <table_to_update>
)

• We can probably replace <id_col> with cartodb_id.
• Maybe we can replace <field_to_update> with the suggested name. This feels like it may be too much.
• Is it possible to use the suggested name in all tabs? In Builder this works and shows names like male_pop_per_sq_km_2015

[antoniocarlon]

Answering your suggestions:

1. Totally. The query with a fixed point doesn't make sense at all
2. 99% of the time <id_col> will be cartodb_id. I'm changing it
3. I prefer keeping the <field_to_update> placeholder. The suggested name is great for the SELECT as it gives you context about the result, but for some users it may be hard to infere that they need a column pop_18_25 (for example) in their table
4. I think it's possible and it would be nice. I'll take a look

[javitonino]

Very nice!

One minor nitpick before letting this go. We should capitalize AS in SELECT cartodb_id as id, the_geom FROM <table_to_update>, for consistency. After that, this is a 🚀