Question

I having a referral table like below.

> id     referredByID  referrerID
> 
> 1001    1              2
> 
> 1002    2              3
> 
> 1003    2              4
>
> 1004    5              7

From the above table structure i need to get the users whom i referred and the users whom are referred by their referrals.

For Example:

• I am referredByID-1

• I referred the ID – 2

• Now the ID – 2 referred ID -3

• And in the same case ID-2 referred ID – 4

Now my output needs to be look like:

Referrals Done By Me:

id – 2

id – 3

id – 4

How can this be done using MYSQL.

Any help will be appreciated.. Thanks in advance…

Answer 1

I think I got everything the right way round but your naming conventions confused me so you’d better check everything.

If I call the following stored procedure:

call referrals_hier(1);

I get the following results:

+--------------+------------+-------+
| referredByID | referrerID | depth |
+--------------+------------+-------+
|            1 |          2 |     0 |
|            2 |          3 |     1 |
|            2 |          4 |     1 |
+--------------+------------+-------+
3 rows in set (0.00 sec)

full script here: http://pastie.org/1466596

Stored procedure

drop table if exists referrals;
create table referrals
(
id smallint unsigned not null primary key,
referrerID smallint unsigned not null,
referredByID smallint unsigned null,
key (referredByID)
)
engine = innodb;

insert into referrals (id, referredByID, referrerID) values
 (1001,1,2),(1002,2,3),(1003,2,4),(1004,5,7);

drop procedure if exists referrals_hier;

delimiter #

create procedure referrals_hier
(
in p_refID smallint unsigned
)
begin

declare v_done tinyint unsigned default(0);
declare v_dpth smallint unsigned default(0);

create temporary table hier(
 referredByID smallint unsigned, 
 referrerID smallint unsigned, 
 depth smallint unsigned
)engine = memory;

insert into hier select referredByID, referrerID, v_dpth from referrals where referredByID = p_refID;

/* http://dev.mysql.com/doc/refman/5.0/en/temporary-table-problems.html */

create temporary table tmp engine=memory select * from hier;

while not v_done do

    if exists( select 1 from referrals e inner join hier on e.referredByID = hier.referrerID and hier.depth = v_dpth) then

        insert into hier select e.referredByID, e.referrerID, v_dpth + 1 
            from referrals e inner join tmp on e.referredByID = tmp.referrerID and tmp.depth = v_dpth;

        set v_dpth = v_dpth + 1;            

        truncate table tmp;
        insert into tmp select * from hier where depth = v_dpth;

    else
        set v_done = 1;
    end if;

end while;

select * from hier order by depth;

drop temporary table if exists hier;
drop temporary table if exists tmp;

end #

delimiter ;

-- call this sproc from your php

call referrals_hier(1);

Hope this helps 🙂