回答編集履歴
1
追加
answer
CHANGED
|
@@ -25,4 +25,32 @@
|
|
|
25
25
|
and dat>t1.dat
|
|
26
26
|
)
|
|
27
27
|
and not_a is not null
|
|
28
|
-
```
|
|
28
|
+
```
|
|
29
|
+
|
|
30
|
+
# 追加
|
|
31
|
+
```SQL
|
|
32
|
+
create table user(name varchar(10),age int, sex set('男','女'));
|
|
33
|
+
insert into user values
|
|
34
|
+
('Bさん',20,'男'),
|
|
35
|
+
('Cさん',30,'女');
|
|
36
|
+
```
|
|
37
|
+
|
|
38
|
+
- ユーザー情報つき
|
|
39
|
+
```SQL
|
|
40
|
+
select * from (
|
|
41
|
+
select no,dat,elt(field('Aさん',to_user,from_user),from_user,to_user) as not_a
|
|
42
|
+
from tbl as t1
|
|
43
|
+
having not exists(select 1
|
|
44
|
+
from tbl
|
|
45
|
+
where 'Aさん' in(to_user,from_user)
|
|
46
|
+
and elt(field('Aさん',to_user,from_user),from_user,to_user)=not_a
|
|
47
|
+
and dat>t1.dat
|
|
48
|
+
)
|
|
49
|
+
and not_a is not null
|
|
50
|
+
)
|
|
51
|
+
as t2
|
|
52
|
+
inner join user as t3 on t2.not_a=t3.name
|
|
53
|
+
```
|
|
54
|
+
※上記だとDさんがuserテーブルにないので消えてしまいます
|
|
55
|
+
ユーザー情報のないuserもnullで個人情報を表示したいなら
|
|
56
|
+
inner joinをleft joinに変えてください
|