function CensusPlus_ForAllCharacters(realmKey, factionKey, raceKey, classKey, guildKey, levelKey, callback)
    for realmName, realmDatabase in pairs(CensusPlus_Database["Servers"]) do
        if ((realmKey == nil) or (realmKey == realmName)) then
            for factionName, factionDatabase in pairs(realmDatabase) do
                if ((factionKey == nil) or (factionKey == factionName)) then
                    for raceName, raceDatabase in pairs(factionDatabase) do
                        if ((raceKey == nil) or (raceKey == raceName)) then
                            for className, classDatabase in pairs(raceDatabase) do
                                if ((classKey == nil) or (classKey == className)) then
                                    for characterName, character in pairs(classDatabase) do
                                    local characterGuild = character[2];
                                        if ((guildKey == nil) or (guildKey == characterGuild)) then
                                            local characterLevel = character[1];
                                            if( characterLevel == nil ) then
                                                characterLevel = 0;
                                            end
                                            if ((levelKey == nil) or (levelKey == characterLevel) or (levelKey < 0 and levelKey + characterLevel ~= 0)) then
                                                callback(characterName, characterLevel, characterGuild, raceName, className, character[3] );
                                            end
                                        end
                                    end
                                end
                            end
                        end
                    end
                end
            end
        end
    end
end