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MySQL JOIN同じテーブルで複数の結合?

    国/都市/地域ごとに2つの個別の参加が必要です。以下は基本的な構文です。パーサーに通していないので、少し変更する必要があるかもしれません:

    SELECT people.first_name AS "First Name", people.last_name AS "Last Name", 
    countries1.name AS "Country1", territories1.name AS "Territory1", cities1.name AS "City1", 
    countries2.name AS "Country2", territories2.name AS "Territory2", cities2.name AS "City2"
    FROM adb_people AS people
    JOIN root_cities AS cities1 ON people.city1 = cities1.id
      AND people.city2 = cities1.id
    JOIN root_territories AS territories1 ON people.prov_state1 = territories1.id
      AND people.prov_state2 = territories1.id
    JOIN root_countries AS countries1 ON people.country1 = countries1.id
    JOIN root_cities AS cities2 ON people.city2 = cities2.id
      AND people.city2 = cities2.id
    JOIN root_territories AS territories2 ON people.prov_state2 = territories2.id
      AND people.prov_state2 = territories2.id
    JOIN root_countries AS countries2 ON people.country2 = countries2.id
    


    1. 行の作成と最終変更のタイムスタンプ

    2. NifiPutSQLタイムスタンプ/日時エラーは変換できませんエラー

    3. Rubymysql2エラー

    4. 文字列を、前に空のスペースがある文字列と、空のスペースがない文字列を比較する