Suggested Query for 4910

This removes unpopulated islands and adds the counties of England.

SELECT
lg1.grid_id
FROM wp_dt_location_grid lg1
WHERE lg1.level = 0
AND lg1.grid_id NOT IN ( SELECT lg11.admin0_grid_id FROM wp_dt_location_grid lg11 WHERE lg11.level = 1 AND lg11.admin0_grid_id = lg1.grid_id )
AND lg1.admin0_grid_id NOT IN (100050711,100219347,100089589,100074576,100259978,100018514,100130478)
AND lg1.population > 200
UNION ALL
SELECT
lg2.grid_id
FROM wp_dt_location_grid lg2
WHERE lg2.level = 1
AND lg2.admin0_grid_id NOT IN (100050711,100219347,100089589,100074576,100259978,100018514,100130478)
AND lg2.population > 200
UNION ALL
SELECT
lg3.grid_id
FROM wp_dt_location_grid lg3
WHERE lg3.level = 2
AND lg3.admin0_grid_id IN (100050711,100219347,100089589,100074576,100259978,100018514,100130478)
AND lg3.population > 200;