php - Use a variable twice in prepared statement -

i'm beginning use prepared statements sql queries in php , in starting have come question.

i have function grabs user's id table @ login. want user able use either username or email address login.

so sql statement is:

select * `login` `username`=? or `emailaddress`=?

now when in query username , emailaddress same because can either or.

so when binding statements bind variable twice:

bind_param('ss', $user, $user); 

so value username , emailaddress needs same. want $user value of both placeholders.

my questions are: am doing correctly? is there more efficient way?

yes, have bind twice. if opposed reason, rephrase query as:

select * `login` l cross join       (select ? thename) const l.`username` = thename or `emailaddress` = thename; 

this using subquery name parameter can referred multiple times in query.