回答編集履歴

1

更新

2022/04/19 05:45

投稿

yambejp
yambejp

スコア114843

test CHANGED
@@ -16,3 +16,21 @@
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  on json_contains(t1.item_id,t2.id)
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  group by id;
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  ```
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+
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+ # jsonにこだわらないバージョン
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+ ```sql
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+ create table user (
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+ id int primary key ,
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+ item_id varchar(20));
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+ insert into user values(1,'1,2');
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+
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+ create table item (
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+ id int primary key ,
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+ name varchar(10));
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+ insert into item values(1,'ノート'),(2,'鉛筆'),(3,'消しゴム');
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+
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+ select t1.id,group_concat(t2.name) from user as t1
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+ inner join item as t2
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+ on find_in_set(t2.id,t1.item_id)
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+ group by id;
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+ ```