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ER図のIE記法(鳥の足ってなんぞ)

Last updated at Posted at 2024-01-16

Crow's Foot 記法

ER 図のための書き方のひとつ

20200223190753.png」のような鳥の足に見える記号を使うため、「Crow's Foot 記法」(Crow's Foot = カラスの足) 「鳥の足記法」と呼ばれています。

わかりやすく見る場合はこちらを

IE記法では、多重度を書く際に1やNのような数字や変数を使わず、専用の記号が使われます。

基本的には、

  • 0(〇を書く)
  • 1( | を書く)
  • たくさん(20200223190753.png
    の3つの基本表記が使われます。

スクリーンショット 2024-01-16 15.23.39.png

リレーションの例

image.png

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