David Blomstrom wrote:
I have a PHP script that displays data like this:
Eurasia
Eurasia<sup>island</sup>
Africa
Where Eurasia and Africa are mainland parents of
ecological regions and Eurasia<sup>island</sup> is a
parent of an ecological system that is associated with
a continent. For example, Borneo would be
Eurasia<sup>island</sup>.
You've lost me here ;-) I know quite a bit about animals, but ecological
regions and their parents are not my cup of tea.
ANIMALS TABLE
Canis_lupus | wolf
Panthera_tigris | tiger
JOIN TABLE
SPECIES | ECOREGION
Canis_lupus | NA1008
Canis_lupus | NA1010
ECOREGIONS TABLE
ID | NAME | Geog | Geog2
NA1008 | Alaska tundra | na | na
IM1003 | Philippine rainforest | eur | phl
(Note that mainland ecoregions feature the continental
ID in each of the last two columns, while island
ecoregions feature the island's ID in the last
column.)
GEOGRAPHY TABLE
ID | NAME
na | North America
phl | Philippines
I miss quite a bit of data here and there are no queries mentioned.
Where can I find Eurasia and Africa here?
Maybe you can start by rewriting the problem is pseudo queries:
"I want a list of the NAMEs from the GEOGRAPHY table for a certain
species from the JOIN table for which the ecoregions and the geog are
listed in the ecoregions table. Each NAME should only appear once."
Or something like that.
With such a natural language pseudo query you're often more than half
way towards building a real query. At least you're far enough for others
to help you build the actual SQL.
Regards, Jigal.
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