I want to show all posts that user had followed. I have two tables are post_tb and follow_tb, linked column is post_tb.user_id and follow_tb.follower_id.
if i show all posts on the table i got sql condition like this
"select * from post_tb order by date_time desc;"
And this is sql condition that show only posts people they followed.
"select * from post_tb where user_id in(select follow_to_id from follow_tb where follow_tb.follower_id='$sessionid') order by date_time des;"
Both of them is work, but the second sql is every slow when number of records increase. Is there the better way?
thanks for your answer
Sub queries are slow instead use join
select * from post_tb p
join follow_tb f ON(p.user_id = f.follow_to_id )
where f.follower_id='$sessionid'
order by date_time desc;