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悬赏园豆:20 [已解决问题] 解决于 2015-12-17 18:03

根据资料上的demo,完成了orm功能,但是一直不能连接到数据库,麻烦看一下!我用的是python3.

orm.py  

# encoding: utf-8
__author__ = 'lenovo'

"""
@author: lenovo
@software: PyCharm
@file: orm.py
@time: 2015/11/28 15:54
@function:ORM框架
"""
import asyncio, logging
import aiomysql

def log(sql, args=()):
logging.info('SQL: %s' % sql)

@asyncio.coroutine
def create_pool(loop, **kw):
logging.info('create database connection pool...')
global __pool
__pool = yield from aiomysql.create_pool(
host=kw.get('host', 'localhost'),
port=kw.get('port', 3306),
user=kw['user'],
password=kw['password'],
db=kw['db'],
charset=kw.get('charset', 'utf8'),
autocommit=kw.get('autocommit', True),
maxsize=kw.get('maxsize', 10),
minsize=kw.get('minsize', 1),
loop=loop
)

@asyncio.coroutine
def select(sql, args, size=None):
log(sql, args)
global __pool
with (yield from __pool) as conn:
cur = yield from conn.cursor(aiomysql.DictCursor)
yield from cur.execute(sql.replace('?', '%s'), args or ())
if size:
rs = yield from cur.fetchmany(size)
else:
rs = yield from cur.fetchall()
yield from cur.close()
logging.info('rows returned: %s' % len(rs))
return rs

@asyncio.coroutine
def execute(sql, args, autocommit=True):
log(sql)
with (yield from __pool) as conn:
if not autocommit:
yield from conn.begin()
try:
cur = yield from conn.cursor()
yield from cur.execute(sql.replace('?', '%s'), args)
affected = cur.rowcount
yield from cur.close()
if not autocommit:
yield from conn.commit()
except BaseException as e:
if not autocommit:
yield from conn.rollback()
raise
return affected

def create_args_string(num):
L = []
for n in range(num):
L.append('?')
return ', '.join(L)

class Field(object):

def __init__(self, name, column_type, primary_key, default):
self.name = name
self.column_type = column_type
self.primary_key = primary_key
self.default = default

def __str__(self):
return '<%s, %s:%s>' % (self.__class__.__name__, self.column_type, self.name)

class StringField(Field):

def __init__(self, name=None, primary_key=False, default=None, ddl='varchar(100)'):
super().__init__(name, ddl, primary_key, default)

class BooleanField(Field):

def __init__(self, name=None, default=False):
super().__init__(name, 'boolean', False, default)

class IntegerField(Field):

def __init__(self, name=None, primary_key=False, default=0):
super().__init__(name, 'bigint', primary_key, default)

class FloatField(Field):

def __init__(self, name=None, primary_key=False, default=0.0):
super().__init__(name, 'real', primary_key, default)

class TextField(Field):

def __init__(self, name=None, default=None):
super().__init__(name, 'text', False, default)

class ModelMetaclass(type):

def __new__(cls, name, bases, attrs):
if name=='Model':
return type.__new__(cls, name, bases, attrs)
tableName = attrs.get('__table__', None) or name
logging.info('found model: %s (table: %s)' % (name, tableName))
mappings = dict()
fields = []
primaryKey = None
for k, v in attrs.items():
if isinstance(v, Field):
logging.info(' found mapping: %s ==> %s' % (k, v))
mappings[k] = v
if v.primary_key:
# 找到主键:
if primaryKey:
raise BaseException('Duplicate primary key for field: %s' % k)
primaryKey = k
else:
fields.append(k)
if not primaryKey:
raise BaseException('Primary key not found.')
for k in mappings.keys():
attrs.pop(k)
escaped_fields = list(map(lambda f: '`%s`' % f, fields))
attrs['__mappings__'] = mappings # 保存属性和列的映射关系
attrs['__table__'] = tableName
attrs['__primary_key__'] = primaryKey # 主键属性名
attrs['__fields__'] = fields # 除主键外的属性名
attrs['__select__'] = 'select `%s`, %s from `%s`' % (primaryKey, ', '.join(escaped_fields), tableName)
attrs['__insert__'] = 'insert into `%s` (%s, `%s`) values (%s)' % (tableName, ', '.join(escaped_fields), primaryKey, create_args_string(len(escaped_fields) + 1))
attrs['__update__'] = 'update `%s` set %s where `%s`=?' % (tableName, ', '.join(map(lambda f: '`%s`=?' % (mappings.get(f).name or f), fields)), primaryKey)
attrs['__delete__'] = 'delete from `%s` where `%s`=?' % (tableName, primaryKey)
return type.__new__(cls, name, bases, attrs)

class Model(dict, metaclass=ModelMetaclass):

def __init__(self, **kw):
super(Model, self).__init__(**kw)

def __getattr__(self, key):
try:
return self[key]
except KeyError:
raise AttributeError(r"'Model' object has no attribute '%s'" % key)

def __setattr__(self, key, value):
self[key] = value

def getValue(self, key):
return getattr(self, key, None)

def getValueOrDefault(self, key):
value = getattr(self, key, None)
if value is None:
field = self.__mappings__[key]
if field.default is not None:
value = field.default() if callable(field.default) else field.default
logging.debug('using default value for %s: %s' % (key, str(value)))
setattr(self, key, value)
return value

@classmethod
@asyncio.coroutine
def findAll(cls, where=None, args=None, **kw):
' find objects by where clause. '
sql = [cls.__select__]
if where:
sql.append('where')
sql.append(where)
if args is None:
args = []
orderBy = kw.get('orderBy', None)
if orderBy:
sql.append('order by')
sql.append(orderBy)
limit = kw.get('limit', None)
if limit is not None:
sql.append('limit')
if isinstance(limit, int):
sql.append('?')
args.append(limit)
elif isinstance(limit, tuple) and len(limit) == 2:
sql.append('?, ?')
args.extend(limit)
else:
raise ValueError('Invalid limit value: %s' % str(limit))
rs = yield from select(' '.join(sql), args)
return [cls(**r) for r in rs]

@classmethod
@asyncio.coroutine
def findNumber(cls, selectField, where=None, args=None):
' find number by select and where. '
sql = ['select %s _num_ from `%s`' % (selectField, cls.__table__)]
if where:
sql.append('where')
sql.append(where)
rs = yield from select(' '.join(sql), args, 1)
if len(rs) == 0:
return None
return rs[0]['_num_']

@classmethod
@asyncio.coroutine
def find(cls, pk):
' find object by primary key. '
rs = yield from select('%s where `%s`=?' % (cls.__select__, cls.__primary_key__), [pk], 1)
if len(rs) == 0:
return None
return cls(**rs[0])

@asyncio.coroutine
def save(self):
args = list(map(self.getValueOrDefault, self.__fields__))
args.append(self.getValueOrDefault(self.__primary_key__))
rows = yield from execute(self.__insert__, args)
if rows != 1:
logging.warn('failed to insert record: affected rows: %s' % rows)

@asyncio.coroutine
def update(self):
args = list(map(self.getValue, self.__fields__))
args.append(self.getValue(self.__primary_key__))
rows = yield from execute(self.__update__, args)
if rows != 1:
logging.warn('failed to update by primary key: affected rows: %s' % rows)

@asyncio.coroutine
def remove(self):
args = [self.getValue(self.__primary_key__)]
rows = yield from execute(self.__delete__, args)
if rows != 1:
logging.warn('failed to remove by primary key: affected rows: %s' % rows)

test.py
import Combat.www.orm as orm,asyncio
from Combat.www.models import User, Blog, Comment

def test():
yield from orm.create_pool(loop = asyncio.get_event_loop(),host='192.168.10.3', user='root', password='admin', db='awesome')
u = User(name='Test', email='test@example.com', password='1234567890', image='about:blank')
yield from u.save()
for x in test():
pass
瀞默的主页 瀞默 | 初学一级 | 园豆:149
提问于:2015-12-01 17:56
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最佳答案
0

参考一下:http://www.tuicool.com/articles/yqayEv

收获园豆:20
silianpan | 小虾三级 |园豆:571 | 2015-12-04 04:02
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