Trying to use q3c_join with the Astro Datalab query interface

Question

While using this website's query interface, I noticed that q3c_join didn't seem to be recognized. Is it only available when you use Astro Data Lab in Python?

Answer 1

Data Lab's website query interface requires queries to be written in ADQL, so the syntax for using Q3C functions is a bit different than what you would use in SQL. Try this:

SELECT count(*)
FROM gnirs_dqs.spec_measurements AS g, sdss_dr17.specobj AS s
WHERE 't' = Q3C_JOIN(g.ra, g.dec, s.ra, s.dec, .001)

Similarly, q3c_radial_query would be expressed like:

SELECT ra, dec
FROM splus_dr2.main
WHERE 't' = Q3C_RADIAL_QUERY(ra, dec, 0.0, 0.0, 0.1) 

(Performs a cone search for objects in S-PLUS DR2 with a distance of 0.1 degrees from the position RA,Dec=0.0,0.0)