Question

I have two column table friends table where it has a recode of users whos friends with eacho other. i want to get a list who’s friends with a specific user. to do that i wrote a sql query as such and got a result..

SELECT * 
FROM  `friends` 
WHERE  `user_idf` =  '2'
OR  `user_idff` =  '2'

++ user_idf ++++   user_idff+++
    2   +   1
    3   +   2   
    4   +   2
    2   +   5
+++++++++++++++++++++++++++

how to write a php function to echo user who’s a friend of 2 (this i will replace with a POST where it gets user id from an application)
i.e.
1, 3, 4, 5

Answer 1

do you mean something like this?

(SELECT `user_idf` FROM `user` WHERE `user_idff` = 2) UNION (SELECT `user_idff` FROM `user` WHERE `user_idf` = 2)

Im not great with sql to be honest, but I think union is what you are looking for (and I think my syntax is correct although im not 100%).

This should from my understanding take the user ids of anyone who is friends with user 2 and output it. The union of results returned when user 2 is in user_idf and user_idff columns.

EDIT: Actually I still stand by my answer, if you don;t do this sql side then you will have to have a more complex PHP function.

For the PHP itself look into mysqli and PDO as your two main options for prepared statements.