mysql - How to handle a bidirectional many-to-many relationship with PHP -

mysql - How to handle a bidirectional many-to-many relationship with PHP -

i trying setup bidirectional many-to-many relationship using same table data, namely user, have link table named userusers joins 1 user user, not sure how handle bidirectional side, because result of code shows 1 direction.

class="lang-sql prettyprint-override">--table user: create table user ( userid int auto_increment not null, userfirstname varchar(30) not null, usersurname varchar(30) not null, usertel char(10), usercell char(10), useremail varchar(50) not null, userpassword varchar(50) not null, userimage varchar(50), useraddress1 varchar(50), useraddress2 varchar(50), usertown/city varchar(50), userprovince varchar(50), usercountry varchar(50), userpostalcode varchar(50), primary key(userid) ) --table userusers: create table userusers ( userid int not null, friendid int not null, primary key(userid, friendid), foreign key(userid) references user(userid), foreign key(friendid) references user(userid) )

php code:

$sql="select * user u inner bring together userusers uu on uu.userid = u.userid inner bring together user f on f.userid = uu.friendid uu.userid = " . $_session['userid'];

actually, no, tables show bidirectional relationships.

consider table usersusers

the column userid represents person friends friendid.

say user 1 wants friends user 2

our usersusers table like:

userid | friendid 1 2

sure, see there relationship between user 1 , 2, see user1 has initiated friendship, showing direction 1 -> 2

now when user2 wants take friendship, can insert record table, making it:

userid | friendid 1 2 2 1

there's improve meta info can add together relationship table understand more relationship created, userid field should considered owner, or sender, , friendid should considered receiver.

so - have of work cutting out you, have create queries deed upon bidirectional relationship.

getting confirmed friends user1:

we assume $the_logged_in_user_id = 1

select * users u bring together usersusers f on u.userid = f.userid f.friendid = '$the_logged_in_user_id'

that show confirmed friendships $the_logged_in_user_id, assuming you're going for.

php mysql