来自不同sql表的个性化php输出

我正在创建一个通知页面,其中 显示4种类型的通知

1) someone liked your post
2) someone shared your post
3) someone added you as a friend
4) someone commented your post

我已经得到了每条语句的sql代码,但我仍然不知道如何将所有内容混合在一个语句中 while($a=sql_array()){} 循环,我知道我应该使用UNION和ORDER by date,但如何为显示的每种类型的通知发布个性化输出

DESIRED OUTPUT

A liked your page
B comment your post
C liked your page
D comment your post
E added you as a friend
F liked your page
G comment your post
H shared your post
I added you as a friend
J shared your post
K shared your post
L liked your page
M added you as a friend
N shared your post
O added you as a friend
P liked your page
Q comment your post
R added you as a friend
S added you as a friend
T comment your post
D liked your page

我有6张桌子

table_users
table_posts 
table_likes
table_shares
table_comments
table_community

每种类型的通知都遵循相同的模式

 SELECT u.`name`, p.post, p.date as OrderDate
  FROM likes (next shares, next, comments, community)
    LEFT JOIN Users as u on likes.id_liker=u.id_user
    LEFT JOIN Users as v on likes.liked_user_id=v.id_user
    LEFT JOIN Posts as p on likes.liked_post_id=p.id_post
         WHERE likes.liked_user_id=3

所以我用 UNION 订购人 OrderDate ,它们检索结果,但没有个性化的通知类型。我想总结一下,因为这是一个巨大的问题。