Home/ Questions/Q 5977751
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-22T21:24:56+00:00

I have a user table with a list of facebook IDs as below. ‘userID’

  • 0

I have a user table with a list of facebook IDs as below. ‘userID’ is a unique key I give to each entry

userID   name          facebookID
1        John Smith    5012991
2        Mark Jones    5912356
3        Bob Doe       814126819

My problem is that I have a list of facebook IDs of the friends of the currently logged in user. As you can imagine this can be anything from 100 to 1000, and I basically need to search my user table for each of the users friends IDs to find if they are already in it (and hence show that their facebook friends are already on my site).

The only way I can think to find a match is to do a foreach loop and run a query for each of the users facebook friends ids, however this could be up to 1000 or more queries at once, which is quite a lot. Is there any way of making this search more efficient, perhaps by using a mySQL function i’m not aware of!

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    You can do a SELECT * FROM friends WHERE facebookID IN (5912356, 814126819); to find all the friends in a given list. You can read up on the IN funciton here: http://dev.mysql.com/doc/refman/5.5/en/comparison-operators.html#function_in, there’s a similar NOT IN function if you need to find friends who are not yet on your list. The PHP function implode() may be useful if you’re trying to turn an array into a string to use in the IN function.

    • 0