{"id":1981,"date":"2022-11-22T14:48:32","date_gmt":"2022-11-22T14:48:32","guid":{"rendered":"https:\/\/c.ipcpu.com\/?p=1981"},"modified":"2023-07-31T14:52:01","modified_gmt":"2023-07-31T14:52:01","slug":"sqlalchemy-filter_by-filter","status":"publish","type":"post","link":"https:\/\/c.ipcpu.com\/2022\/11\/sqlalchemy-filter_by-filter\/","title":{"rendered":"SQLALchemy\u4e2d\u7684\u8fc7\u6ee4\u65b9\u6cd5filter_by()\u548cfilter()\u7528\u6cd5\u548c\u533a\u522b"},"content":{"rendered":"

filter_by() \u548c filter() \u7684\u6700\u4e3b\u8981\u7684\u533a\u522b\uff1a<\/h3>\n

\"\"<\/a><\/p>\n

\u8c08 filter_by() \u7684\u8bed\u6cd5\u4e4b\u524d\u5148\u770b\u4e0b filter_by() \u7684\u5185\u90e8\u6e90\u7801,\u53bb\u6389\u6ce8\u91ca\u4e4b\u540e\u5982\u4e0b:<\/p>\n

    def filter_by(self, **kwargs):\n        clauses = [_entity_descriptor(self._joinpoint_zero(), key) == value\n                   for key, value in kwargs.items()]\n        return self.filter(sql.and_(*clauses))<\/code><\/pre>\n
\u6211\u4eec\u53ef\u4ee5\u770b\u5230filter_by()\u5c31\u662ffilter()\u7b80\u5316\u7248\uff0c\u4ec5\u652f\u6301\u5c11\u90e8\u5206\u529f\u80fd\u3002<\/p>\n
1.filter_by\u7684\u7528\u6cd5<\/h2>\n
filter_by\u7528\u4e8e\u67e5\u8be2\u7b80\u5355\u7684\u5217\u540d\uff0c\u4e0d\u652f\u6301\u6bd4\u8f83\u8fd0\u7b97\u7b26\u3002
\n\u8bed\u6cd5\uff1a column = expression
\n\u4f20\u5165\u53c2\u6570\u7684\u5199\u6cd5\uff0c\u53ea\u9700\u8981\u7528\uff1a\uff08\u4e0d\u5e26\u7c7b\u540d\u7684\uff09\u5217\u540d \u5355\u4e2a\u7b49\u53f7 \u5c31\u53ef\u4ee5\u5224\u65ad\u3002<\/p>\n
\u4e3e\u4f8b\uff1a<\/p>\n
query(User.name).filter_by(fullname='Ed Jones')\n\nfilters = {'name':'fengyao','age': 26}\nUser.query.filter_by(**filters).first()\n\n#\u67e5\u8be2 user \u8868\u91cc\u9762\u540d\u5b57\u7b49\u4e8e Tom \u7684\uff1a\ndb.session.query(User).filter_by(name='Tom').all()\n#\u67e5\u8be2 user \u8868\u91cc\u9762\u540d\u5b57\u7b49\u4e8e Tom \u5e76\u4e14\u5e74\u9f84\u7b49\u4e8e 18\uff1a\ndb.session.query(User).filter_by(name='Tom', age=18).all()<\/code><\/pre>\n
\u6bd4\u5982\u65b0\u7684\u9700\u6c42\uff0c\u67e5\u8be2 user \u8868\u91cc\u9762\u540d\u5b57\u7b49\u4e8e Tom \u6216\u8005\u5e74\u9f84\u7b49\u4e8e 18 \u7684\u7528\u6237\uff0c\u90a3\u4e48 filter_by() \u5c31\u6ee1\u8db3\u4e0d\u4e86\u8981\u6c42\u4e86<\/p>\n
2.filter\u7684\u7528\u6cd5<\/h2>\n
filter\u4e2d\uff0c\u8bed\u6cd5\u66f4\u52a0\u8d34\u8fd1\u4e8e\uff0c\u7c7b\u4f3c\u4e8e\uff0cPython\u7684\u8bed\u6cd5\u3002
\n\u6bd4filter_by\u7684\u529f\u80fd\u66f4\u5f3a\u5927\uff0c\u4e14\u66f4\u590d\u6742\u7684\u67e5\u8be2\u7684\u8bed\u6cd5\uff0c\u6bd4\u5982and()\uff0cor()\u7b49\u591a\u4e2a\u6761\u4ef6\u7684\u67e5\u8be2\uff0c\u53ea\u652f\u6301filter
\n\u8bed\u6cd5\uff1a column == expression
\n\u4f20\u5165\u53c2\u6570\u7684\u5199\u6cd5\uff0c\u8981\u7528\uff1a\u7c7b\u540d.\u5217\u540d \u4e24\u4e2a\u7b49\u53f7 \u53bb\u5224\u65ad<\/p>\n
\u4e3e\u4f8b\uff1a<\/p>\n
query(User.name).filter(User.fullname=='Ed Jones')\nquery.filter(or_(User.name =='ed', User.name =='wendy'))\nquery.filter(and_(User.name =='ed', User.fullname =='Ed Jones'))\n\nfilters = {\n     User.name =='fengyao',\n     User.age > 25\n}\nUser.query.filter(*filters).first()\n\n#\u67e5\u8be2 user \u8868\u91cc\u9762\u540d\u5b57\u7b49\u4e8e Tom \u7684\uff1a\ndb.session.query(User).filter(User.name =='Tom').all()\n#\u67e5\u8be2 user \u8868\u91cc\u9762\u540d\u5b57\u7b49\u4e8e Tom \u5e76\u4e14\u5e74\u9f84\u7b49\u4e8e 18\uff1a\ndb.session.query(User).filter(User.name =='Tom', User.age == 18).all()\n#\u4e5f\u53ef\u4ee5\u8fd9\u6837\uff1a\ndb.session.query(User).filter(User.name =='Tom'\uff09.filter(User.age == 18).all()\n#\u5982\u679c\u60f3\u4f7f\u7528 and \u62fc\u63a5\u9700\u8981\u7528\u4ee5\u4e0b\u65b9\u5f0f\uff1a\ndb.session.query(User).filter(and_(User.name =='Tom', User.age == 18)).all()\n#\u4ee5\u4e0b\u7684\u65b9\u5f0f and \u540e\u9762\u7684 User.age == 18 \u4e0d\u4f1a\u751f\u6548\uff1a\ndb.session.query(User).filter(User.name =='Tom' and User.age == 18).all()\n#\u67e5\u8be2 user \u8868\u91cc\u9762\u540d\u5b57\u7b49\u4e8e Tom \u7684\u6216\u8005\u5e74\u9f84\u7b49\u4e8e 18\uff1a\ndb.session.query(User).filter(or_(User.name =='Tom', User.age == 18)).all()\n#\u67e5\u8be2 user \u8868\u91cc\u9762\u540d\u5b57\u7b49\u4e8e Tom \u7684\u5e76\u4e14\u5e74\u9f84\u5927\u4e8e 18\ndb.session.query(User).filter(User.name =='Tom', User.age > 18).all()\n#\u67e5\u8be2 name \u4e2d\u5305\u542b\u5b57\u6bcd a \u7684\u6240\u6709\u6570\u636e(\u6a21\u7cca\u67e5\u8be2)\ndb.session.query(User).filter(User.name.like('%{0}%'.format("a"))).all()<\/code><\/pre>\n
\u53c2\u8003\u8d44\u6599<\/h2>\n
https:\/\/www.jianshu.com\/p\/ca9bc9f8adab<\/a>
\nhttps:\/\/segmentfault.com\/q\/1010000000140472<\/a><\/p>\n
\u8f6c\u8f7d\u8bf7\u6ce8\u660e\uff1aIPCPU-\u7f51\u7edc\u4e4b\u8def<\/a> » SQLALchemy\u4e2d\u7684\u8fc7\u6ee4\u65b9\u6cd5filter_by()\u548cfilter()\u7528\u6cd5\u548c\u533a\u522b<\/a><\/p>","protected":false},"excerpt":{"rendered":"
filter_by() \u548c filter() \u7684\u6700\u4e3b\u8981\u7684\u533a\u522b\uff1a \u8c08 filter_by() \u7684\u8bed\u6cd5\u4e4b\u524d\u5148\u770b\u4e0b filter_by() \u7684\u5185\u90e8\u6e90\u7801,\u53bb\u6389\u6ce8\u91ca\u4e4b\u540e\u5982\u4e0b: def filter_by(self, **kwargs): clauses = [_entity_descriptor(self._joinpoint_zero(), key) == value for key, value in kwargs.items()] return self.filter(sql.and_(*clauses)) \u6211\u4eec\u53ef\u4ee5\u770b\u5230filter_by()\u5c31\u662ffilter()\u7b80\u5316\u7248\uff0c\u4ec5\u652f\u6301\u5c11\u90e8\u5206\u529f\u80fd\u3002 1.filter_by\u7684\u7528\u6cd5 filter_by\u7528\u4e8e\u67e5\u8be2\u7b80\u5355\u7684\u5217\u540d\uff0c\u4e0d\u652f\u6301\u6bd4\u8f83\u8fd0\u7b97\u7b26\u3002 \u8bed\u6cd5\uff1a column = expression \u4f20\u5165\u53c2\u6570\u7684\u5199\u6cd5\uff0c\u53ea\u9700\u8981\u7528\uff1a\uff08\u4e0d\u5e26\u7c7b\u540d\u7684\uff09\u5217\u540d \u5355\u4e2a\u7b49\u53f7 \u5c31\u53ef\u4ee5\u5224\u65ad\u3002 \u4e3e\u4f8b\uff1a query(User.name).filter_by(fullname='Ed Jones') filters = {'name':'fengyao','age': 26} User.query.filter_by(**filters).first() #\u67e5\u8be2 user \u8868\u91cc\u9762\u540d\u5b57\u7b49\u4e8e Tom \u7684\uff1a db.session.query(User).filter_by(name='Tom').all() #\u67e5\u8be2 user \u8868\u91cc\u9762\u540d\u5b57\u7b49\u4e8e Tom \u5e76\u4e14\u5e74\u9f84\u7b49\u4e8e 18\uff1a […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[13],"tags":[59],"_links":{"self":[{"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/posts\/1981"}],"collection":[{"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/comments?post=1981"}],"version-history":[{"count":1,"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/posts\/1981\/revisions"}],"predecessor-version":[{"id":1983,"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/posts\/1981\/revisions\/1983"}],"wp:attachment":[{"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/media?parent=1981"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/categories?post=1981"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/c.ipcpu.com\/wp-json\/wp\/v2\/tags?post=1981"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}