Which plugin will let me relate one post to another? [closed]

If you want to generate those connections automatically, based on a certain algorithm, then YARPP would probably do the job nicely.

If you want control over each connection, then you might want to take a look at Posts 2 Posts.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)