mysql - Nearest free coordinates in database -


i have x , z coordinates in database. coordinates integers.

each coordinate bigger or equal 0.

i need nearest free (not in database) coordinates 0;0 don't want limit 1 coordinate specified number.

again, don't want nearest coordinate in database, want nearest free coordinate.

this did myself. tells me free space in coordinates square (limited maximum x , maximum z coordinates in database).

problem cannot select free coordinates that. distance free coordinates not coordinates.

select distance (     select (x+z) distance,count(owner) count     coordinates      group x+z asc ) coor coor.distance != coor.count-1

i'd try that:

select x, z (     select x, z+1 z coordinates union     select x+1, z coordinates union     select x+1, z+1 coordinates union     select 0, 0 ) q     concat(x,'_',z) not in (select concat(x,'_',z) coordinates) order (x+z) asc limit 1

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