try:
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select visiturl,count(id) as visits from table1 group by concat(ip,visiturl) order by visits desc limit 0,5;
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select visiturl,count(id) as visits from table1 group by concat(ip,visiturl) order by visits desc limit 0,5;
select visiturl,count(distinct ip) as urlcount
from table
group by visiturl
order by urlcount desc
limit 5