回答編集履歴
3
推敲
test
CHANGED
|
@@ -34,7 +34,7 @@
|
|
|
34
34
|
|
|
35
35
|
|
|
36
36
|
|
|
37
|
-
質問にある、「tag
|
|
37
|
+
質問にある、「tag='大阪'」を含むデータの抽出は以下です。
|
|
38
38
|
|
|
39
39
|
```SQL
|
|
40
40
|
|
2
推敲
test
CHANGED
|
@@ -50,7 +50,7 @@
|
|
|
50
50
|
|
|
51
51
|
ON t.tag_id = at.tag_id
|
|
52
52
|
|
|
53
|
-
WHERE at.a_id in (select a_id from a_tag where tag
|
|
53
|
+
WHERE at.a_id in (select a_id from a_tag where tag = '大阪')
|
|
54
54
|
|
|
55
55
|
GROUP BY at.a_id
|
|
56
56
|
|
|
@@ -72,7 +72,7 @@
|
|
|
72
72
|
|
|
73
73
|
ON t.tag_id = at.tag_id
|
|
74
74
|
|
|
75
|
-
WHERE exists (select 1 from a_tag where tag
|
|
75
|
+
WHERE exists (select 1 from a_tag where tag = '大阪' and a_id = at.a_id)
|
|
76
76
|
|
|
77
77
|
GROUP BY at.a_id
|
|
78
78
|
|
1
追記
test
CHANGED
|
@@ -31,3 +31,49 @@
|
|
|
31
31
|
```
|
|
32
32
|
|
|
33
33
|
ただ、データ上GROUP_CONCAT()でDistinctが必要な状況ならDistinctが不要になるようにしておいた方が良いと思われます。
|
|
34
|
+
|
|
35
|
+
|
|
36
|
+
|
|
37
|
+
質問にある、「tag_id='大阪'」を含むデータの抽出は以下です。
|
|
38
|
+
|
|
39
|
+
```SQL
|
|
40
|
+
|
|
41
|
+
SELECT at.a_id
|
|
42
|
+
|
|
43
|
+
, GROUP_CONCAT(DISTINCT t.tag_id)
|
|
44
|
+
|
|
45
|
+
, GROUP_CONCAT(DISTINCT t.tag)
|
|
46
|
+
|
|
47
|
+
FROM a_tag at
|
|
48
|
+
|
|
49
|
+
inner join tag t
|
|
50
|
+
|
|
51
|
+
ON t.tag_id = at.tag_id
|
|
52
|
+
|
|
53
|
+
WHERE at.a_id in (select a_id from a_tag where tag_id = '大阪')
|
|
54
|
+
|
|
55
|
+
GROUP BY at.a_id
|
|
56
|
+
|
|
57
|
+
```
|
|
58
|
+
|
|
59
|
+
または
|
|
60
|
+
|
|
61
|
+
```SQL
|
|
62
|
+
|
|
63
|
+
SELECT at.a_id
|
|
64
|
+
|
|
65
|
+
, GROUP_CONCAT(DISTINCT t.tag_id)
|
|
66
|
+
|
|
67
|
+
, GROUP_CONCAT(DISTINCT t.tag)
|
|
68
|
+
|
|
69
|
+
FROM a_tag at
|
|
70
|
+
|
|
71
|
+
inner join tag t
|
|
72
|
+
|
|
73
|
+
ON t.tag_id = at.tag_id
|
|
74
|
+
|
|
75
|
+
WHERE exists (select 1 from a_tag where tag_id = '大阪' and a_id = at.a_id)
|
|
76
|
+
|
|
77
|
+
GROUP BY at.a_id
|
|
78
|
+
|
|
79
|
+
```
|