使用sqlalchemy和postgresql编码错误

Question

我正在将金字塔用于带有postgres数据库,wtforms,sqlalchemy和jinja2的Web应用程序,当应用程序尝试从数据库中获取问题类型以填充带有wtforms的选择字段时,我遇到此错误:

Error: 'ascii' codec can't decode byte 0xc3 in position 5: ordinal not in range(128)

这是model.py中的问题类型表:

class Mixin(object):
    id = Column(Integer, primary_key=True, autoincrement=True)
    created = Column(DateTime())
    modified = Column(DateTime())

    __table_args__ = {
        'mysql_engine': 'InnoDB',
        'mysql_charset': 'utf8'
    }
    __mapper_args__ = {'extension': BaseExtension()}

class IssueType(Mixin, Base):
    __tablename__ = "ma_issue_types"
    name = Column(Unicode(40), nullable=False)

    def __init__(self, name):
        self.name = name

进入bd我有这个:

# select name from ma_issue_types where id = 3;
name    
------------
Teléfono

这是发生错误的部分

# -*- coding: utf-8 -*-

from issuemall.models import DBSession, IssueType


class IssueTypeDao(object):

    def getAll(self):
        dbsession = DBSession()
        return dbsession.query(IssueType).all() #HERE THROWS THE ERROR

这是Traceback

Traceback (most recent call last):
  File "/issueMall/issuemall/controller/issueRegisterController.py", line 16, in issue_register
    form = IssueRegisterForm(request.POST)
  File "/env/lib/python2.7/site-packages/wtforms/form.py", line 178, in __call__
    return type.__call__(cls, *args, **kwargs)
  File "/env/lib/python2.7/site-packages/wtforms/form.py", line 224, in __init__
    super(Form, self).__init__(self._unbound_fields, prefix=prefix)
  File "/env/lib/python2.7/site-packages/wtforms/form.py", line 39, in __init__
    field = unbound_field.bind(form=self, name=name, prefix=prefix, translations=translations)
  File "/env/lib/python2.7/site-packages/wtforms/fields/core.py", line 301, in bind
    return self.field_class(_form=form, _prefix=prefix, _name=name, _translations=translations, *self.args, **dict(self.kwargs, **kwargs))
  File "/issueMall/issuemall/form/generalForm.py", line 11, in __init__
    types = issueTypeDao.getAll()
  File "/issueMall/issuemall/dao/master/issueTypeDao.py", line 11, in getAll
    return self.__dbsession.query(IssueType).all()
  File "build/bdist.linux-x86_64/egg/sqlalchemy/orm/query.py", line 2115, in all
    return list(self)
  File "build/bdist.linux-x86_64/egg/sqlalchemy/orm/query.py", line 2341, in instances
    fetch = cursor.fetchall()
  File "build/bdist.linux-x86_64/egg/sqlalchemy/engine/base.py", line 3205, in fetchall
    l = self.process_rows(self._fetchall_impl())
  File "build/bdist.linux-x86_64/egg/sqlalchemy/engine/base.py", line 3172, in _fetchall_impl
    return self.cursor.fetchall()
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 5: ordinal not in range(128)

我试试这个,但它不能在python中作为默认编码使用 ascii

我尝试这样的东西,但它没有用

gae python ascii编解码器无法解码字节

return dbsession.query(IssueType.id, IssueType.name.encode('utf-8')).all() #or decode('utf-8')

Answer 1

您需要配置Psycopg2的客户端编码.请参阅SQLAlchemy文档:

默认情况下,psycopg2驱动程序使用psycopg2.extensions.UNICODE扩展,以便DBAPI直接接收并返回所有字符串作为Python Unicode对象 - SQLAlchemy无需更改即可传递这些值.这里的Psycopg2将根据当前的"客户端编码"设置对字符串值进行编码/解码; 默认情况下,这是postgresql.conf文件中的值,通常默认为SQL_ASCII.通常,这可以更改utf-8为更有用的默认值:

#client_encoding = sql_ascii # actually, defaults to database
                             # encoding
client_encoding = utf8

影响客户端编码的第二种方法是在本地将其设置在Psycopg2中.SQLAlchemy的将调用psycopg2的set_client_encoding()方法(参见:http://initd.org/psycopg/docs/connection.html#connection.set_client_encoding)基于传递到值的所有新连接create_engine()使用的client_encoding参数:

engine = create_engine("postgresql://user:pass@host/dbname", client_encoding='utf8')

这将覆盖Postgresql客户端配置中指定的编码.

该client_encoding参数可以指定为引擎URL中的查询字符串:

 postgresql://user:pass@host/dbname?client_encoding=utf8