{"id":4887,"date":"2022-03-28T18:46:33","date_gmt":"2022-03-28T10:46:33","guid":{"rendered":"https:\/\/egonlin.com\/?p=4887"},"modified":"2022-04-26T13:48:39","modified_gmt":"2022-04-26T05:48:39","slug":"%e7%ac%ac%e4%b8%83%e8%8a%82%ef%bc%9aorm%e6%a1%86%e6%9e%b6sqlalchemy","status":"publish","type":"post","link":"https:\/\/egonlin.com\/?p=4887","title":{"rendered":"\u7b2c\u4e03\u8282\uff1aORM\u6846\u67b6SQLAlchemy"},"content":{"rendered":"

\u4e00 \u4ecb\u7ecd<\/h1>\n

SQLAlchemy\u662fPython\u7f16\u7a0b\u8bed\u8a00\u4e0b\u7684\u4e00\u6b3eORM\u6846\u67b6\uff0c\u8be5\u6846\u67b6\u5efa\u7acb\u5728\u6570\u636e\u5e93API\u4e4b\u4e0a\uff0c\u4f7f\u7528\u5173\u7cfb\u5bf9\u8c61\u6620\u5c04\u8fdb\u884c\u6570\u636e\u5e93\u64cd\u4f5c\uff0c\u7b80\u8a00\u4e4b\u4fbf\u662f\uff1a\u5c06\u5bf9\u8c61\u8f6c\u6362\u6210SQL\uff0c\u7136\u540e\u4f7f\u7528\u6570\u636eAPI\u6267\u884cSQL\u5e76\u83b7\u53d6\u6267\u884c\u7ed3\u679c\u3002<\/p>\n

1\u3001\u5b89\u88c5<\/h2>\n
pip3 install sqlalchemy <\/code><\/pre>\n
2\u3001\u67b6\u6784\u4e0e\u6d41\u7a0b<\/h2>\n
\"\"<\/div><\/p>\n
#1\u3001\u4f7f\u7528\u8005\u901a\u8fc7ORM\u5bf9\u8c61\u63d0\u4ea4\u547d\u4ee4\n#2\u3001\u5c06\u547d\u4ee4\u4ea4\u7ed9SQLAlchemy Core\uff08Schema\/Types  SQL Expression Language\uff09\u8f6c\u6362\u6210SQL\n#3\u3001\u4f7f\u7528 Engine\/ConnectionPooling\/Dialect \u8fdb\u884c\u6570\u636e\u5e93\u64cd\u4f5c\n#3.1\u3001\u5339\u914d\u4f7f\u7528\u8005\u4e8b\u5148\u914d\u7f6e\u597d\u7684egine\n#3.2\u3001egine\u4ece\u8fde\u63a5\u6c60\u4e2d\u53d6\u51fa\u4e00\u4e2a\u94fe\u63a5\n#3.3\u3001\u57fa\u4e8e\u8be5\u94fe\u63a5\u901a\u8fc7Dialect\u8c03\u7528DB API\uff0c\u5c06SQL\u8f6c\u4ea4\u7ed9\u5b83\u53bb\u6267\u884c<\/code><\/pre>\n
\uff01\uff01\uff01\u4e0a\u8ff0\u6d41\u7a0b\u5206\u6790\uff0c\u53ef\u4ee5\u5927\u81f4\u5206\u4e3a\u4e24\u4e2a\u9636\u6bb5\uff01\uff01\uff01\uff1a<\/strong><\/p>\n
#\u7b2c\u4e00\u4e2a\u9636\u6bb5\uff08\u6d41\u7a0b1-2\uff09\uff1a\u5c06SQLAlchemy\u7684\u5bf9\u8c61\u6362\u6210\u53ef\u6267\u884c\u7684sql\u8bed\u53e5\n\n#\u7b2c\u4e8c\u4e2a\u9636\u6bb5\uff08\u6d41\u7a0b3\uff09\uff1a\u5c06sql\u8bed\u53e5\u4ea4\u7ed9\u6570\u636e\u5e93\u6267\u884c<\/code><\/pre>\n
\u5982\u679c\u6211\u4eec\u4e0d\u4f9d\u8d56\u4e8eSQLAlchemy\u7684\u8f6c\u6362\u800c\u81ea\u5df1\u5199\u597dsql\u8bed\u53e5\uff0c\u90a3\u662f\u4e0d\u662f\u610f\u5473\u7740\u53ef\u4ee5\u76f4\u63a5\u4ece\u7b2c\u4e8c\u4e2a\u9636\u6bb5\u5f00\u59cb\u6267\u884c\u4e86\uff0c\u4e8b\u5b9e\u4e0a\u6b63\u662f\u5982\u6b64\uff0c\u6211\u4eec\u5b8c\u5168\u53ef\u4ee5\u53ea\u7528SQLAlchemy\u6267\u884c\u7eafsql\u8bed\u53e5\uff0c\u5982\u4e0b<\/p>\n
from sqlalchemy import create_engine\n\n#1 \u51c6\u5907\n# \u9700\u8981\u4e8b\u5148\u5b89\u88c5\u597dpymysql\n# \u9700\u8981\u4e8b\u5148\u521b\u5efa\u597d\u6570\u636e\u5e93:create database db1 charset utf8;\n\n#2 \u521b\u5efa\u5f15\u64ce\negine=create_engine('mysql+pymysql:\/\/root@127.0.0.1\/db1?charset=utf8')\n\n#3 \u6267\u884csql\n# egine.execute('create table if not EXISTS t1(id int PRIMARY KEY auto_increment,name char(32));')\n\n# cur=egine.execute('insert into t1 values(%s,%s);',[(1,"egon1"),(2,"egon2"),(3,"egon3")]) #\u6309\u4f4d\u7f6e\u4f20\u503c\n\n# cur=egine.execute('insert into t1 values(%(id)s,%(name)s);',name='egon4',id=4) #\u6309\u5173\u952e\u5b57\u4f20\u503c\n\n#4 \u65b0\u63d2\u5165\u884c\u7684\u81ea\u589eid\n# print(cur.lastrowid)\n\n#5 \u67e5\u8be2\ncur=egine.execute('select * from t1')\n\ncur.fetchone() #\u83b7\u53d6\u4e00\u884c\ncur.fetchmany(2) #\u83b7\u53d6\u591a\u884c\ncur.fetchall() #\u83b7\u53d6\u6240\u6709\u884c<\/code><\/pre>\n
3\u3001DB API<\/h2>\n
SQLAlchemy\u672c\u8eab\u65e0\u6cd5\u64cd\u4f5c\u6570\u636e\u5e93\uff0c\u5176\u5fc5\u987b\u4ee5\u6765pymsql\u7b49\u7b2c\u4e09\u65b9\u63d2\u4ef6\uff0cDialect\u7528\u4e8e\u548c\u6570\u636eAPI\u8fdb\u884c\u4ea4\u6d41\uff0c\u6839\u636e\u914d\u7f6e\u6587\u4ef6\u7684\u4e0d\u540c\u8c03\u7528\u4e0d\u540c\u7684\u6570\u636e\u5e93API\uff0c\u4ece\u800c\u5b9e\u73b0\u5bf9\u6570\u636e\u5e93\u7684\u64cd\u4f5c\uff0c\u5982\uff1a<\/p>\n
#1\u3001MySQL-Python\n    mysql+mysqldb:\/\/<user>:<password>@<host>[:<port>]\/<dbname>\n\n#2\u3001pymysql\n    mysql+pymysql:\/\/<username>:<password>@<host>\/<dbname>[?<options>]\n\n#3\u3001MySQL-Connector\n    mysql+mysqlconnector:\/\/<user>:<password>@<host>[:<port>]\/<dbname>\n\n#4\u3001cx_Oracle\n    oracle+cx_oracle:\/\/user:pass@host:port\/dbname[?key=value&key=value...]\n\n\u66f4\u591a\u8be6\u89c1\uff1ahttp:\/\/docs.sqlalchemy.org\/en\/latest\/dialects\/index.html <\/code><\/pre>\n
\u4e8c \u521b\u5efa\u8868<\/h1>\n
ORM\u4e2d\uff1a<\/p>\n
#\u7c7b===>\u8868\n#\u5bf9\u8c61==>\u8868\u4e2d\u7684\u4e00\u884c\u8bb0\u5f55<\/code><\/pre>\n
\u56db\u5f20\u8868:\u4e1a\u52a1\u7ebf,\u670d\u52a1,\u7528\u6237,\u89d2\u8272\uff0c\u5229\u7528ORM\u521b\u5efa\u51fa\u5b83\u4eec\uff0c\u5e76\u5efa\u7acb\u597d\u5b83\u4eec\u76f4\u63a5\u7684\u5173\u7cfb<\/p>\n
from sqlalchemy import create_engine\nfrom sqlalchemy.ext.declarative import declarative_base\nfrom sqlalchemy import Column,Integer,String,DateTime,Enum,ForeignKey,UniqueConstraint,ForeignKeyConstraint,Index\nfrom sqlalchemy.orm import sessionmaker\n\negine=create_engine('mysql+pymysql:\/\/root@127.0.0.1:3306\/db1?charset=utf8',max_overflow=5)\n\nBase=declarative_base()\n\n#\u521b\u5efa\u5355\u8868:\u4e1a\u52a1\u7ebf\nclass Business(Base):\n    __tablename__='business'\n    id=Column(Integer,primary_key=True,autoincrement=True)\n    bname=Column(String(32),nullable=False,index=True)\n\n#\u591a\u5bf9\u4e00:\u591a\u4e2a\u670d\u52a1\u53ef\u4ee5\u5c5e\u4e8e\u4e00\u4e2a\u4e1a\u52a1\u7ebf,\u591a\u4e2a\u4e1a\u52a1\u7ebf\u4e0d\u80fd\u5305\u542b\u540c\u4e00\u4e2a\u670d\u52a1\nclass Service(Base):\n    __tablename__='service'\n    id=Column(Integer,primary_key=True,autoincrement=True)\n    sname=Column(String(32),nullable=False,index=True)\n    ip=Column(String(15),nullable=False)\n    port=Column(Integer,nullable=False)\n\n    business_id=Column(Integer,ForeignKey('business.id'))\n\n    __table_args__=(\n        UniqueConstraint(ip,port,name='uix_ip_port'),\n        Index('ix_id_sname',id,sname)\n    )\n\n#\u4e00\u5bf9\u4e00:\u4e00\u79cd\u89d2\u8272\u53ea\u80fd\u7ba1\u7406\u4e00\u6761\u4e1a\u52a1\u7ebf,\u4e00\u6761\u4e1a\u52a1\u7ebf\u53ea\u80fd\u88ab\u4e00\u79cd\u89d2\u8272\u7ba1\u7406\nclass Role(Base):\n    __tablename__='role'\n    id=Column(Integer,primary_key=True,autoincrement=True)\n    rname=Column(String(32),nullable=False,index=True)\n    priv=Column(String(64),nullable=False)\n\n    business_id=Column(Integer,ForeignKey('business.id'),unique=True)\n\n#\u591a\u5bf9\u591a:\u591a\u4e2a\u7528\u6237\u53ef\u4ee5\u662f\u540c\u4e00\u4e2arole,\u591a\u4e2arole\u53ef\u4ee5\u5305\u542b\u540c\u4e00\u4e2a\u7528\u6237\nclass Users(Base):\n    __tablename__='users'\n    id=Column(Integer,primary_key=True,autoincrement=True)\n    uname=Column(String(32),nullable=False,index=True)\n\nclass Users2Role(Base):\n    __tablename__='users2role'\n    id=Column(Integer,primary_key=True,autoincrement=True)\n    uid=Column(Integer,ForeignKey('users.id'))\n    rid=Column(Integer,ForeignKey('role.id'))\n\n    __table_args__=(\n        UniqueConstraint(uid,rid,name='uix_uid_rid'),\n    )\n\ndef init_db():\n    Base.metadata.create_all(egine)\n\ndef drop_db():\n    Base.metadata.drop_all(egine)\n\nif __name__ == '__main__':\n    init_db()<\/code><\/pre>\n
\u6ce8\uff1a\u8bbe\u7f6e\u5916\u952e\u7684\u53e6\u4e00\u79cd\u65b9\u5f0f ForeignKeyConstraint([‘other_id’],[‘othertable.other_id’])<\/p>\n
\u4e09 \u589e\u5220\u6539\u67e5<\/h1>\n
\u8868\u7ed3\u6784<\/p>\n
from sqlalchemy import create_engine\nfrom sqlalchemy.ext.declarative import declarative_base\nfrom sqlalchemy import Column,Integer,String,ForeignKey\nfrom sqlalchemy.orm import sessionmaker\n\negine=create_engine('mysql+pymysql:\/\/root@127.0.0.1:3306\/db1?charset=utf8',max_overflow=5)\n\nBase=declarative_base()\n\n#\u591a\u5bf9\u4e00:\u5047\u8bbe\u591a\u4e2a\u5458\u5de5\u53ef\u4ee5\u5c5e\u4e8e\u4e00\u4e2a\u90e8\u95e8,\u800c\u591a\u4e2a\u90e8\u95e8\u4e0d\u80fd\u6709\u540c\u4e00\u4e2a\u5458\u5de5(\u53ea\u6709\u521b\u5efa\u516c\u53f8\u624d\u628a\u5458\u5de5\u5f53\u9a86\u9a7c\u7528,\u4e00\u4e2a\u5458\u5de5\u8eab\u517c\u6570\u804c)\nclass Dep(Base):\n    __tablename__='dep'\n    id=Column(Integer,primary_key=True,autoincrement=True)\n    dname=Column(String(64),nullable=False,index=True)\n\nclass Emp(Base):\n    __tablename__='emp'\n    id=Column(Integer,primary_key=True,autoincrement=True)\n    ename=Column(String(32),nullable=False,index=True)\n    dep_id=Column(Integer,ForeignKey('dep.id'))\n\ndef init_db():\n    Base.metadata.create_all(egine)\n\ndef drop_db():\n    Base.metadata.drop_all(egine)\n\ndrop_db()\ninit_db()\nSession=sessionmaker(bind=egine)\nsession=Session()<\/code><\/pre>\n
\u589e<\/p>\n
#\u589e\nrow_obj=Dep(dname='\u9500\u552e') #\u6309\u5173\u952e\u5b57\u4f20\u53c2,\u65e0\u9700\u6307\u5b9aid,\u56e0\u5176\u662f\u81ea\u589e\u957f\u7684\nsession.add(row_obj)\nsession.add_all([\n    Dep(dname='\u6280\u672f'),\n    Dep(dname='\u8fd0\u8425'),\n    Dep(dname='\u4eba\u4e8b'),\n])\n\nsession.commit()<\/code><\/pre>\n
\u5220<\/p>\n
\n#\u5220\nsession.query(Dep).filter(Dep.id > 3).delete()\nsession.commit()\n<\/code><\/pre>\n
\u6539<\/p>\n
#\u6539\nsession.query(Dep).filter(Dep.id > 0).update({'dname':'\u54c7\u54c8\u54c8'})\nsession.query(Dep).filter(Dep.id > 0).update({'dname':Dep.dname+'_SB'},synchronize_session=False)\nsession.query(Dep).filter(Dep.id > 0).update({'id':Dep.id*100},synchronize_session='evaluate')\n\nsession.commit()<\/code><\/pre>\n
\u67e5<\/p>\n
#\u67e5\u6240\u6709,\u53d6\u6240\u6709\u5b57\u6bb5\nres=session.query(Dep).all() #for row in res:print(row.id,row.dname)\n\n#\u67e5\u6240\u6709,\u53d6\u6307\u5b9a\u5b57\u6bb5\nres=session.query(Dep.dname).order_by(Dep.id).all() #for row in res:print(row.dname)\n\nres=session.query(Dep.dname).first()\nprint(res) # ('\u54c7\u54c8\u54c8_SB',)\n\n#\u8fc7\u6ee4\u67e5\nres=session.query(Dep).filter(Dep.id > 1,Dep.id <1000) #\u9017\u53f7\u5206\u9694,\u9ed8\u8ba4\u4e3aand\nprint([(row.id,row.dname) for row in res])<\/code><\/pre>\n
\u56db \u5176\u4ed6\u67e5\u8be2\u76f8\u5173<\/h1>\n
\u4e00 \u51c6\u5907\u8868\u548c\u6570\u636e<\/h2>\n
\u590d\u5236\u4ee3\u7801\n\nfrom sqlalchemy import create_engine\nfrom sqlalchemy.ext.declarative import declarative_base\nfrom sqlalchemy import Column,Integer,String,ForeignKey\nfrom sqlalchemy.orm import sessionmaker\n\negine=create_engine('mysql+pymysql:\/\/root@127.0.0.1:3306\/db1?charset=utf8',max_overflow=5)\n\nBase=declarative_base()\n\n#\u591a\u5bf9\u4e00:\u5047\u8bbe\u591a\u4e2a\u5458\u5de5\u53ef\u4ee5\u5c5e\u4e8e\u4e00\u4e2a\u90e8\u95e8,\u800c\u591a\u4e2a\u90e8\u95e8\u4e0d\u80fd\u6709\u540c\u4e00\u4e2a\u5458\u5de5(\u53ea\u6709\u521b\u5efa\u516c\u53f8\u624d\u628a\u5458\u5de5\u5f53\u9a86\u9a7c\u7528,\u4e00\u4e2a\u5458\u5de5\u8eab\u517c\u6570\u804c)\nclass Dep(Base):\n    __tablename__='dep'\n    id=Column(Integer,primary_key=True,autoincrement=True)\n    dname=Column(String(64),nullable=False,index=True)\n\nclass Emp(Base):\n    __tablename__='emp'\n    id=Column(Integer,primary_key=True,autoincrement=True)\n    ename=Column(String(32),nullable=False,index=True)\n    dep_id=Column(Integer,ForeignKey('dep.id'))\n\ndef init_db():\n    Base.metadata.create_all(egine)\n\ndef drop_db():\n    Base.metadata.drop_all(egine)\n\ndrop_db()\ninit_db()\nSession=sessionmaker(bind=egine)\nsession=Session()\n\n# \u51c6\u5907\u6570\u636e\nsession.add_all([\n    Dep(dname='\u6280\u672f'),\n    Dep(dname='\u9500\u552e'),\n    Dep(dname='\u8fd0\u8425'),\n    Dep(dname='\u4eba\u4e8b'),\n])\n\nsession.add_all([\n    Emp(ename='\u6797\u6d77\u5cf0',dep_id=1),\n    Emp(ename='\u674e\u6770',dep_id=1),\n    Emp(ename='\u6b66\u914d\u9f50',dep_id=1),\n    Emp(ename='\u5143\u660a',dep_id=2),\n    Emp(ename='\u674e\u94a2\u5f39',dep_id=3),\n    Emp(ename='\u5f20\u4e8c\u4e2b',dep_id=4),\n    Emp(ename='\u674e\u5766\u514b',dep_id=2),\n    Emp(ename='\u738b\u5927\u70ae',dep_id=4),\n    Emp(ename='\u725b\u69b4\u5f39',dep_id=3)\n])\n\nsession.commit()<\/code><\/pre>\n
\u4e8c \u6761\u4ef6\u3001\u901a\u914d\u7b26\u3001limit\u3001\u6392\u5e8f\u3001\u5206\u7ec4\u3001\u8fde\u8868\u3001\u7ec4\u5408<\/h2>\n
<\/p>
<\/div>
\u67e5\u770b\u66f4\u591a<\/h2>
\u8054\u7cfb\u7ba1\u7406\u5458\u5fae\u4fe1tutu19192010\uff0c\u6ce8\u518c\u8d26\u53f7<\/p>\n<\/div>
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<\/div>","protected":false},"excerpt":{"rendered":"
\u4e00 \u4ecb\u7ecd SQLAlchemy\u662fPython\u7f16\u7a0b\u8bed\u8a00\u4e0b\u7684\u4e00\u6b3eORM\u6846\u67b6\uff0c\u8be5\u6846\u67b6\u5efa\u7acb\u5728\u6570\u636e\u5e93API\u4e4b\u4e0a\uff0c\u4f7f\u7528\u5173\u7cfb […]<\/p>\n","protected":false},"author":3,"featured_media":6750,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[3,403],"tags":[],"_links":{"self":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/4887"}],"collection":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4887"}],"version-history":[{"count":0,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/posts\/4887\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=\/wp\/v2\/media\/6750"}],"wp:attachment":[{"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4887"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4887"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/egonlin.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4887"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}