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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\xdf\xa1@i\xd6>V\xc0\xbb\x8fp\x16#Z\x0b\x81\xeb\x16'
DEBUG = True