if ur friend host the db follow this..
WHO HOST THE DB
1-open navicat
2-double click on the connection ur friend wish to share
3-right click and click manage user
4-new window open click on add user
5-under username put 1234 for example/for host put your ip(

)
6-password and confirm password use the same thing(put anything u want)
7-click ok and you're done on hoster pc
WHO SHARING THE DB
1-open navicat
2-click connection-->MySQL
3-connection name put anything u want
4-host name/ip address put
WHO HOST THE DB IP it can be find here (

)
5-port leave default
6-username put your username u create on
WHO HOST THE DB
7-password put your password u create on
WHO HOST THE DB
8-click ok then u're done..
be happy and goodluck