Parse error: syntax error, unexpected T_STRING in C:\xampp\htdocs\index.php on line 21 [on hold]

Parse error: syntax error, unexpected T_STRING in
C:\xampp\htdocs\index.php on line 21 [on hold]

$data= mysql_fetch_object(mysql_query('SELECT 'like','unlike' FROM posts
WHERE id="'.$postid.'"'));
Please help to sort out this issue please anyone