{"id":1579,"date":"2018-02-25T11:48:27","date_gmt":"2018-02-25T02:48:27","guid":{"rendered":"http:\/\/www.python.ambitious-engineer.com\/?p=1579"},"modified":"2018-02-25T11:52:18","modified_gmt":"2018-02-25T02:52:18","slug":"sqlalchemy%e5%85%a5%e9%96%80-orm%e3%81%9d%e3%81%ae4-%e3%83%aa%e3%83%ac%e3%83%bc%e3%82%b7%e3%83%a7%e3%83%b3%e3%81%a8join","status":"publish","type":"post","link":"https:\/\/www.python.ambitious-engineer.com\/archives\/1579","title":{"rendered":"SQLAlchemy\u5165\u9580 ORM \u305d\u306e4 \u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\u3068JOIN"},"content":{"rendered":"

\u524d\u56de\u3001\u30c6\u30fc\u30d6\u30eb\u9593\u306e\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\u3092\u8003\u616e\u3057\u306a\u3044JOIN\u306b\u3064\u3044\u3066\u5b66\u7fd2\u3057\u307e\u3057\u305f\u3002\u4eca\u56de\u306f\u30c6\u30fc\u30d6\u30eb\u30af\u30e9\u30b9\u306b\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\u3092\u5b9a\u7fa9\u3059\u308b\u65b9\u6cd5\u3068\u305d\u308c\u3089\u304c\u8003\u616e\u3055\u308c\u305fJOIN\u306b\u3064\u3044\u3066\u5b66\u7fd2\u3057\u307e\u3057\u3087\u3046\u3002<\/p>\n

relationship\u3068join<\/h2>\n

\u3042\u308b\u30c6\u30fc\u30d6\u30eb\u306e\u30ec\u30b3\u30fc\u30c9\u306b\u5bfe\u3057\u3066\u3001\u5225\u306e\u30c6\u30fc\u30d6\u30eb\u306e\u30ec\u30b3\u30fc\u30c9\u304c\u8907\u6570\u7d10\u3065\u304f\u3088\u3046\u306a\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\u3067\u3059\u3002\u4f8b\u3048\u3070\u3001\u30d6\u30ed\u30b0\u30b7\u30b9\u30c6\u30e0\u306b\u304a\u3051\u308b\u30e6\u30fc\u30b6\u30fc\u3068\u6295\u7a3f\u306e\u95a2\u4fc2\u306a\u3069\u304c\u3053\u308c\u306b\u8a72\u5f53\u3057\u307e\u3059\u306d\u3002\u5b50\u30c6\u30fc\u30d6\u30eb\u306b\u5916\u90e8\u30ad\u30fc\u3092\u5b9a\u7fa9\u3057\u3001\u89aa\u30c6\u30fc\u30d6\u30eb\u30af\u30e9\u30b9\u5185\u3067\u4ee5\u4e0b\u306e\u3088\u3046\u306brelationship\u95a2\u6570\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002<\/p>\n

\r\n\u5b50\u5c5e\u6027 = relationship("\u5b50\u30c6\u30fc\u30d6\u30eb")\r\n<\/pre>\n
\u524d\u56de\u306e\u30b5\u30f3\u30d7\u30eb\u306bOne To Many\u306e\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\u5b9a\u7fa9\u3092\u8ffd\u52a0\u3057\u305f\u30b5\u30f3\u30d7\u30eb\u3092\u898b\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n
\r\nfrom sqlalchemy import Table, Column, Integer, ForeignKey, String\r\nfrom sqlalchemy.orm import relationship\r\nfrom sqlalchemy.ext.declarative import declarative_base\r\nfrom sqlalchemy import create_engine\r\nfrom sqlalchemy.orm import sessionmaker\r\n\r\n# DB\u63a5\u7d9a\r\nengine = create_engine('sqlite:\/\/\/:memory:')\r\n\r\nBase = declarative_base()\r\n\r\n\r\nclass User(Base):\r\n    __tablename__ = 'users'\r\n    id = Column(Integer, primary_key=True)\r\n    name = Column(String)\r\n    age = Column(Integer)\r\n\r\n    posts = relationship("Post", backref="users")    # Post\u3068\u306e\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\r\n\r\n\r\nclass Post(Base):\r\n    __tablename__ = 'posts'\r\n    id = Column(Integer, primary_key=True)\r\n    users_id = Column(Integer, ForeignKey('users.id'))\r\n    title = Column(String)\r\n    body = Column(Integer)\r\n\r\n    user = relationship("User")    # User\u3068\u306e\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\r\n\r\n# \u30c6\u30fc\u30d6\u30eb\u30af\u30e9\u30b9\u306e\u30c6\u30fc\u30d6\u30eb\u3092\u751f\u6210\r\nBase.metadata.create_all(engine)\r\n\r\n# \u30bb\u30c3\u30b7\u30e7\u30f3\u751f\u6210\r\nSession = sessionmaker(bind=engine)\r\nsession = Session()\r\n\r\n# \u30b5\u30f3\u30d7\u30eb\u30c7\u30fc\u30bf\u633f\u5165\r\nsession.add(User(id=1, name="Suzuki", age=19))\r\nsession.add(User(id=2, name="Tanaka", age=21))\r\nsession.add(User(id=3, name="Sato", age=21))\r\n\r\nsession.add(Post(users_id=1, title="\u671d\u306e\u4f53\u64cd", body="\u30e9\u30b8\u30aa\u4f53\u64cd\u3067\u5143\u6c17\u3044\u3063\u3071\u3044"))\r\nsession.add(Post(users_id=1, title="\u4eca\u65e5\u306e\u5915\u98df", body="\u30ab\u30ec\u30fc\u30e9\u30b9\u304c\u3068\u3066\u3082\u7f8e\u5473\u3057\u304b\u3063\u305f\u3002"))\r\nsession.add(Post(users_id=2, title="\u4ed5\u4e8b", body="\u4eca\u65e5\u306fDjango\u3067API\u4f5c\u6210\u3002"))\r\nsession.add(Post(users_id=2, title="Python\u697d\u3057\u3044", body="Python\u697d\u3057\u3044\u3067\u3059\u3088\u306d\uff01\uff01"))\r\nsession.commit()\r\n\r\n# inner join\u306e\u30b5\u30f3\u30d7\u30eb\r\nusers = session.query(User).join(Post, User.id == Post.users_id).all()\r\n\r\nfor user in users:\r\n    print("%s\u3055\u3093\u306e\u6295\u7a3f" % (user.name))\r\n    for post in user.posts:\r\n        print("|- \u30bf\u30a4\u30c8\u30eb\uff1a%s" % (post.title,))\r\n    print('')\r\n\r\n<\/pre>\n
\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u5b9f\u884c\u7d50\u679c\u304c\u5f97\u3089\u308c\u307e\u3059\u3002\u524d\u56de\u306e\u30b5\u30f3\u30d7\u30eb\u3068\u7570\u306a\u308a\u3001\u7d50\u679c\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u304c\u968e\u5c64\u5316\u3055\u308c\u3066\u3044\u308b\u3053\u3068\u304c\u78ba\u8a8d\u3067\u304d\u307e\u3059\u3002<\/p>\n
\r\nSuzuki\u3055\u3093\u306e\u6295\u7a3f\r\n|- \u30bf\u30a4\u30c8\u30eb\uff1a\u671d\u306e\u4f53\u64cd\r\n|- \u30bf\u30a4\u30c8\u30eb\uff1a\u4eca\u65e5\u306e\u5915\u98df\r\n\r\nTanaka\u3055\u3093\u306e\u6295\u7a3f\r\n|- \u30bf\u30a4\u30c8\u30eb\uff1a\u4ed5\u4e8b\r\n|- \u30bf\u30a4\u30c8\u30eb\uff1aPython\u697d\u3057\u3044\r\n<\/pre>\n
\u307e\u305f\u3001relationship\u95a2\u6570\u306e\u5f15\u6570\u306bback_populates\u3001backref\u3001uselist\u306a\u3069\u306e\u5f15\u6570\u3092\u6307\u5b9a\u3059\u308b\u3053\u3068\u306b\u3088\u308a\u3001\u95a2\u4fc2\u306e\u53cc\u65b9\u5411\u6027\u3084\u30e6\u30cb\u30fc\u30af\u6027\u3092\u5b9a\u7fa9\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u3053\u308c\u3089\u306e\u7d44\u307f\u5408\u308f\u305b\u306b\u3088\u308aOne To Many\u3001Many To One\u3001One To One\u3001Many To Many\u3001\u30a2\u30bd\u30b7\u30a8\u30fc\u30b7\u30e7\u30f3\u3068\u3044\u3063\u305f\u95a2\u4fc2\u3092\u5b9a\u7fa9\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u524d\u56de\u3001\u30c6\u30fc\u30d6\u30eb\u9593\u306e\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\u3092\u8003\u616e\u3057\u306a\u3044JOIN\u306b\u3064\u3044\u3066\u5b66\u7fd2\u3057\u307e\u3057\u305f\u3002\u4eca\u56de\u306f\u30c6\u30fc\u30d6\u30eb\u30af\u30e9\u30b9\u306b\u30ea\u30ec\u30fc\u30b7\u30e7\u30f3\u3092\u5b9a\u7fa9\u3059\u308b\u65b9\u6cd5\u3068\u305d\u308c\u3089\u304c\u8003\u616e\u3055\u308c\u305fJOIN\u306b\u3064\u3044\u3066\u5b66\u7fd2\u3057\u307e\u3057\u3087\u3046\u3002 relationship\u3068join \u3042\u308b\u30c6\u30fc\u30d6...<\/p>\n","protected":false},"author":1,"featured_media":1577,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[169,3,10],"tags":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.python.ambitious-engineer.com\/wp-json\/wp\/v2\/posts\/1579"}],"collection":[{"href":"https:\/\/www.python.ambitious-engineer.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.python.ambitious-engineer.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.python.ambitious-engineer.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.python.ambitious-engineer.com\/wp-json\/wp\/v2\/comments?post=1579"}],"version-history":[{"count":7,"href":"https:\/\/www.python.ambitious-engineer.com\/wp-json\/wp\/v2\/posts\/1579\/revisions"}],"predecessor-version":[{"id":1599,"href":"https:\/\/www.python.ambitious-engineer.com\/wp-json\/wp\/v2\/posts\/1579\/revisions\/1599"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.python.ambitious-engineer.com\/wp-json\/wp\/v2\/media\/1577"}],"wp:attachment":[{"href":"https:\/\/www.python.ambitious-engineer.com\/wp-json\/wp\/v2\/media?parent=1579"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.python.ambitious-engineer.com\/wp-json\/wp\/v2\/categories?post=1579"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.python.ambitious-engineer.com\/wp-json\/wp\/v2\/tags?post=1579"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}