Please try the SQL given below. This SQL is NOT tested, but should return records with origin_service == destination_service. Please refer to Subqueries with ANY, IN, and SOME

SELECT 
    a.stop_reference, 
    b.service_id, 
    distance(PointFromText('POINT($origin)', 27700),east_north), 
    c.route_number 
FROM 
    bus_stops a, 
    service b, 
    routes c 
WHERE 
    distance(PointFromText('POINT($origin)', 27700),east_north) < 200 
    AND 
        a.stop_reference = b.stop_reference 
    AND 
        b.service_id = c.service_id 
    AND
        b.service_id IN (
        SELECT 
            DISTINCT e.service_id 
        FROM 
            bus_stops d, 
            service e, 
            routes f 
        WHERE 
            distance(PointFromText('POINT($dest)', 27700),east_north) 
+< 200 
            AND 
            d.stop_reference = e.stop_reference 
            AND 
            e.service_id = f.service_id 
        ORDER BY 
            e.service_id, 
            distance(PointFromText('POINT($dest)', 27700),east_north) 
    )
ORDER BY 
    b.service_id, 
    distance(PointFromText('POINT($origin)', 27700),east_north)

[download]

--VC

In reply to Re^3: Comparing two variables from different loops by atemon
in thread Comparing two variables from different loops by Harch84

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.