I am working on a query to identify which group ids exists within a spatial cell. In this case i have the GREG table which has polygon data and the priogrid_land which have the cell polygon. I want to identify which and how many GREG group ids exists within each of the priogrid_land cells.
I have tried the below query, but i cannot find a way to select only DISTINCT into the ARRAY_AGG function. I also do not want 0 to be included in the array or 0 to be counted.
Any suggestions on how to accomplish the above? Thanks!
Code:
SELECT priogrid_land.gid, priogrid_land.cell, array_to_string(array_agg(g1id), ';') AS g1list, array_to_string(array_agg(g2id), ';') AS g2list, array_to_string(array_agg(g3id), ';') AS g3list,
count(distinct g1id) AS g1count, count(distinct g2id) AS g2count, count(distinct g3id) AS g3count
INTO greg_list
FROM "GREG", priogrid_land WHERE ST_Intersects("GREG".the_geom, priogrid_land.cell)
GROUP BY priogrid_land.gid, priogrid_land.cell;
This will give this result: g1list; g2list; g3list; g1count; g2count; g3count "482";"0";"0";1;1;1 "23;482;482";"0;0;0";"0;0;0";2;1;1 "1227;482;23";"0;0;0";"0;0;0";3;1;1 "1227;23;482;66";"0;0;0;0";"0;0;0;0";4;1;1 "1227;23;66";"0;0;0";"0;0;0";3;1;1
As you see i.e. in g1list 482 is counted twice in row 2. 0 is also counted. The distinct works for count, but not for array_agg.
