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データベースにて文字数が最大、最小のデータを抽出する方法

hackerrank挑戦時、つまずいたため、備忘用に記録。

データベースより文字数が最小のデータを抽出するには、

MAX(LENGTH(カラム名))

こんな感じでいけるかなと、思いきやこれではエラー。

正解は、

SELECT カラム名 FROM テーブル名 ORDER BY LENGTH(カラム名) LIMIT 1;

文字数が最大の場合は、

SELECT カラム名 FROM テーブル名 ORDER BY LENGTH(カラム名) DESC LIMIT 1;

これでいける。

文字列の長さにてソートして、LIMIT 1 で1つだけデータを抽出するイメージ。
もちろんLIMIT 1 を指定しなければ文字列の長さが小さい順(DESCをつければ大きい順)に表示される。

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