Question

In my script I pass Object ID as querystring parameter. like ?idobject=1962

Now first I have to access from the OBJECTS table the GeoLat and GeoLng columns
and I have to check again if there are other objects containing the same Geo Data

SELECT GeoLng, GeoLat
FROM OBJECTS
WHERE ID = 1962   

from above query I have to read the GeoLng and GeoLat variables and have to write the second query as follows

SELECT O.ID
FROM OBJECTS O
WHERE GeoLng = '12.72812515' /* will be taken from above query */
AND GeoLat   = '47.7794388' /* will be taken from above query */

AND EXISTS(
    SELECT ID 
    FROM InfObjects 
    WHERE ID = O.ID
    )

Can I write these 2 queries into a single query?
Thanks

Answer 1

Edit: Updated based on Rich’s comment.

What you need is a self-join.

SELECT O2.ID
FROM OBJECTS O1
JOIN OBJECTS O2 on O1.GeoLng = O2.GeoLng AND O1.GeoLat = O2.GeoLng
WHERE O1.ID = 1962   
AND EXISTS(
    SELECT ID 
    FROM InfObjects 
    WHERE ID = O2.ID
)

Or even more efficiently, like this:

SELECT O2.ID
FROM OBJECTS O1
JOIN OBJECTS O2 on O1.GeoLng = O2.GeoLng AND O1.GeoLat = O2.GeoLng
JOIN InfObjects I ON O2.ID = I.ID
WHERE O1.ID = 1962