Question

I’m creating a social network. I want to have a user be able to subscribe to people. In theory, when a user clicks the subscribe button, PHP would add that user’s ID to an array in their MYSQL listing under the column “subscribed-to”. Now, I want to have a news feed style home page. I want to know, if I pull the “subscribed-to” data via PHP, how could I show only the posts (also in a MYSQL table) of the people the user is subscribed to?

Answer 1

Use UNION to combine all the posts from different tables, then use the “IN” clause to get all the userID’s you want to follow based on the current userID:

Example:

$userFavs = "SELECT userID FROM favs WHERE followerID = '#loggedinUserID#'"

mysql_query("SELECT 'wall' as type, body, date FROM wall WHERE userID IN ($userFavs) 
UNION
SELECT 'photo' as type, caption, date FROM photos WHERE userID IN ($userFavs) UNION... etc
ORDER BY date DESC");

If you run the query thru mysql_fetch_array() it’ll return something like this:

Array => {
[0] => { type = "wall", body = "This is a wall update", date = "1234567890" },
[1] => { type = "photo", caption = "Us at the beach", date = "..." },
...
}

You need to make sure that you have the same amount of columns in each SELECT statement everytime you call “UNION”, otherwise it will not work. You can /fake/ columns as I have done with the type column above.