[英]Using a variable on sqlalchemy query filter
它可以在过滤器上使用变量吗?
我的实际代码:
import sqlalchemy
from sqlalchemy import Table, MetaData, Column, Integer, String
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.declarative import declarative_base
location = 'localhost'
engine_str = 'mysql+mysqlconnector://xxx:xxx@xxx/xxx'.format(location)
engine = sqlalchemy.create_engine(engine_str, echo=False)
session = sessionmaker(bind=engine)
connection = engine.connect()
session = session(bind=connection)
metadata = MetaData()
Base = declarative_base()
class Services(Base):
"""
Service details on database
"""
__tablename__ = 'some_table'
id = Column(Integer, primary_key=True)
color= Column(String)
shape= Column(String)
def __repr__(self):
return self.shape
这有效:
for c in session.query(Services).filter(Services.name.in_(['blue','red'])):
print(c)
结果:
circle, square
但是使用可变的,返回:
services = ('blue','red')
for c in session.query(Services).filter(Services.name.in_([services])):
print(c)
结果:
mysql.connector.errors.ProgrammingError: Failed processing pyformat-parameters; 'MySQLConverter' object has no attribute '_tuple_to_mysql'
提前致谢!
services
已经是一个序列,不需要将它包装在一个列表中:
for c in session.query(Services).filter(Services.name.in_(services)):
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