This document illustrates how to write a DALI-compliant examples document using TAP's special table and query properties. Apart from the actual examples blocks, you can add arbitrary additional material, for instance, a table of contents:
Use the W3C RDFa validator to see what semantics your RDFa actually conveys.
This example shows how to combine the ↗califadr3.objects table of properties of CALIFA target galaxies with the ↗califadr3.cubes table of data cubes to select bright, early-type spirals:
SELECT target_name, accref, hubtyp, magg
FROM califadr3.cubes
NATURAL JOIN califadr3.objects
WHERE hubtyp in ('S d', 'S cd', 'S c')
AND magg<13
When querying against geometric columns, in particular coverage, use ADQL's contains or intersect functions, like this:
SELECT accref, seeing
FROM cars.images
WHERE 1=INTERSECTS(coverage, circle('', 34, -4, 2))
ORDER BY seeing
Of course, this concerns all SIAP and SSAP tables (↗cars.images only standing as an example here) as well as ↗ivoa.obscore