使用 sqlalchemy 和 postgresql 编码错误 [英] Encoding error with sqlalchemy and postgresql

问题描述

我将金字塔用于带有 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使用 wtforms 填充选择字段时出现此错误:

I'm using pyramid for a web application with a postgres database, wtforms, sqlalchemy and jinja2 and I'm having this error when the application try to get the issues types from database to fill a select field with wtforms:

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:

this is the issue types table into model.py:

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:

Into bd I have this:

# 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

这是回溯

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)

我试过了，但没有用ascii 作为 python 中的默认编码

我尝试了类似的方法，但没有用

and I try something like this, but it did not work

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')

推荐答案

您需要配置 Psycopg2 的客户端编码.请参阅 SQLAlchemy 文档:

You need to configure Psycopg2's client encoding. See the SQLAlchemy documentation:

默认情况下，psycopg2 驱动程序使用 psycopg2.extensions.UNICODE 扩展，这样 DBAPI 直接接收和返回所有字符串作为 Python Unicode 对象 - SQLAlchemy 不加更改地传递这些值.此处的 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，这可以更改为 utf-8，作为更有用的默认值:

By default, the psycopg2 driver uses the psycopg2.extensions.UNICODE extension, such that the DBAPI receives and returns all strings as Python Unicode objects directly - SQLAlchemy passes these values through without change. Psycopg2 here will encode/decode string values based on the current "client encoding" setting; by default this is the value in the postgresql.conf file, which often defaults to SQL_ASCII. Typically, this can be changed to utf-8, as a more useful default:

#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 Psycopg2 中设置它.SQLAlchemy 将调用 psycopg2 的 set_client_encoding() 方法(参见:http://initd.org/psycopg/docs/connection.html#connection.set_client_encoding) 基于传递给 create_engine() 的值使用 client_encoding 参数:

A second way to affect the client encoding is to set it within Psycopg2 locally. SQLAlchemy will call psycopg2’s set_client_encoding() method (see: http://initd.org/psycopg/docs/connection.html#connection.set_client_encoding) on all new connections based on the value passed to create_engine() using the client_encoding parameter:

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

这会覆盖 Postgresql 客户端配置中指定的编码.

This overrides the encoding specified in the Postgresql client configuration.

client_encoding 参数可以指定为引擎 URL 中的查询字符串:

The client_encoding parameter can be specified as a query string in the engine URL:

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

这篇关于使用 sqlalchemy 和 postgresql 编码错误的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！