sqlalchemy 和 flask-sqlalchemy 分表
对于 sqlalchemy 和 flask-sqlalchemy 分表的方案，网上的资料很少，经过google和自己项目的尝试，找到比较合适的解决的方案。
下面的 user 表根据用户的ID % 100 分布在 0 - 99 张表中。
另外，如果要处理分库的话，只需要在model中加入 __bind_key__，等于分库的规则。
sqlalchemy 分表示例： #!/usr/bin/env python # -*- coding: utf-8 -*- from sqlalchemy import Column, Integer, String, BigInteger, SmallInteger from sqlalchemy import create_engine from sqlalchemy.orm import Session from sqlalchemy.ext.declarative import declarative_base Base = declarative_base() class UserData(object): _mapper = {} @staticmethod def model(user_id): table_index = user_id % 100 class_name = 'user_%d' % table_index ModelClass = UserData._mapper.get(class_name, None) if ModelClass is None: ModelClass = type(class_name, (Base,), dict( __module__=__name__, __name__=class_name, __tablename__='user_%d' % table_index, id=Column(BigInteger, primary_key=True), name=Column(String(255)), picture=Column(String(255)), valid=Column(SmallInteger), utime=Column(Integer), ctime=Column(Integer) )) UserData._mapper[class_name] = ModelClass cls = ModelClass return cls if __name__ == '__main__': engine = create_engine('mysql+pymysql://%s:%s@%s:%s/%s' % ('root', 'root', '127.0.0.1', '3306', 'test'), encoding='utf8') Base.metadata.create_all(engine) session = Session(engine) # user_id = 100001 user_id = 1000001 user = UserData.model(user_id) result_1 = session.query(user).count() result_2 = session.query(user).filter(user.name == "test", user.valid == 0).all() result_3 = session.query(user).filter_by(name="test", valid=0).all() print(result_1, result_2, result_3) flask-sqlalchemy 分表示例： #!/usr/bin/env python # -*- coding: utf-8 -*- from flask import Flask, jsonify from flask_sqlalchemy import SQLAlchemy app = Flask(__name__) app.config.from_pyfile('flask-sqlalchmey-sharding.cfg') db = SQLAlchemy(app) class User(object): '''用户分表''' _mapper = {} @staticmethod def model(user_id): table_index = user_id % 100 # db_index = int((user_id % 100) / 25) class_name = 'user_%d' % table_index ModelClass = User._mapper.get(class_name, None) if ModelClass is None: ModelClass = type(class_name, (db.Model,), { '__module__': __name__, '__name__': class_name, '__tablename__': 'user_%d' % table_index, 'id': db.Column(db.BigInteger, primary_key=True), 'name': db.Column(db.String(100)), 'phone': db.Column(db.String(20)), 'status': db.Column(db.SmallInteger, default=0), 'ctime': db.Column(db.Integer, default=0), 'utime': db.Column(db.Integer, default=0) }) User._mapper[class_name] = ModelClass cls = ModelClass return cls @app.route('/ /test', methods=['GET', 'POST']) def test(user_id): user = User.model(user_id) count = user.query.filter_by(id=user_id).count() item = user.query.filter(user.id == user_id, user.status == 0).first() # default name = item.name if item else "default" return jsonify(count=count, name=name) if __name__ == '__main__': app.run()
flask-sqlalchmey-sharding.cfg 文件： SQLALCHEMY_DATABASE_URI = = 'mysql+pymysql://root:root@localhost:3306/test' SQLALCHEMY_ECHO = True SECRET_KEY = '\xfb\x12\xd ...
