Can't work out MySQL Query -

i have mysql table has following data.

surveyid | staff  | username | ipaddress | rating  | comments  ---------|--------|----------|-----------|---------|---------- 0        | staff1 | user1    | 1.1.1.1   | 10      | none 1        | staff2 | user2    | 1.2.1.1   | 5       | none 2        | staff2 | user3    | 1.2.1.1   | 10      | none 3        | staff2 | user2    | 1.2.1.1   | 6       | none 4        | staff3 | user4    | 1.1.1.51  | 10      | none 5        | staff4 | user3    | 1.21.12.1 | 9       | none 6        | staff5 | user2    | 1.12.1.1  | 10      | none 

i wanting query select surveyid, staff, username , ipaddress when ipaddress has been used multiple users same staff.

basicly wanting find out staff has multiple users submit off same ip address.

i have tried following not work.

select * `comment_data` cd  inner join (select `ipaddress`, count(distinct `staff`) `comment_data` group `ipaddress` having count(distinct `staff`) > 1 ) usecount on usecount.`ipaddress` = cd.`ipaddress` 

i tried following query.

select * `commend_data` `staff`+`ipaddress` in (select `staff`+`ipaddress` `comment_data` group `staff`, `ipaddress` having count(`surveyid`) > 1)  

also want make sure display duplicates , don't want display counts.

if need more information please ask.

thanks paul

select surveyid, staff, username, ipaddress table1 ipaddress+staff in  ( select ipaddress+staff table1 group ipaddress,staff having count(surveyid)>1 ) 

sql fiddle