114-解决mysqlclient安装失败,及django使用mysql的一个天坑
作者:互联网
安装好MySQL之后,直接用Python进行操作是可以的,假设要在django中使用mysql,还需要安装pymysql,话不多说,直接安装:
pip3 install pymysql --user
安装完之后,在setting进行如下配置:
1、首先在django工程的setting.py里,引入pymysql:
import os import pymysql pymysql.install_as_MySQLdb()
2、接着,在mysql里创建一个数据库,用来存储django里要存取的表格:
lzh@lzh-pc:~$ mysql -u root -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 9 Server version: 8.0.17 MySQL Community Server - GPL Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> CREATE DATABASE test_app CHARACTER SET utf8; Query OK, 1 row affected, 1 warning (0.01 sec) mysql> SHOW DATABASES; +--------------------+ | Database | +--------------------+ | information_schema | | mysql | | performance_schema | | sys | | test_app | +--------------------+ 5 rows in set (0.00 sec)
3、最后,配置django工程里的setting.py的database部分。其中name是在mysql里定义的某个数据库名:
# Database # https://docs.djangoproject.com/en/2.2/ref/settings/#databases DATABASES = { 'default': { 'ENGINE': 'django.db.backends.mysql', 'NAME': 'test_app', 'USER': 'root', 'PASSWORD': '19830427', 'HOST': 'localhost', 'PORT': '3306', } }
4、高能预警!
此时无论是直接runserver,还是makemigrations,都会报错,大致是:
raise ImproperlyConfigured('mysqlclient 1.3.13 or newer is required; you have %s.' % Database.__version__) django.core.exceptions.ImproperlyConfigured: mysqlclient 1.3.13 or newer is required; you have 0.9.3.
但是请注意,如果用pip3 list查看,是根本没有mysqlclient这个包的,一定会有人想,如果没有这个包(或者版本太低),装一下不就行了。
5、安装mysqlclient,官网上列举了这些前置需求:
sudo apt-get install python3-dev
sudo apt-get install
default-libmysqlclient-dev
如果把这两个安装完成后,再安装mysqlclient,仍然会报错,而且会报错一整屏幕红字,非常惊悚,仔细一看,主要是这里的问题:
/usr/bin/ld: 找不到 -lssl /usr/bin/ld: 找不到 -lcrypto
安装其中一个即可:sudo apt-get install libssl-dev
【注意是libssl,少一个l】
到这里,就能正常安装mysqlclient了,使用命令:pip3 install mysqlclient --user
然后再用pip3 list就能查看到:
mysqlclient 1.4.4
到了这里,你以为问题解决了,然后能愉快地运行runserver或makemigrations?非常遗憾!
仍然会报错:django.core.exceptions.ImproperlyConfigured: mysqlclient 1.3.13 or newer is required; you have 0.9.3.
这就不是版本的问题了,而是它永远都会出错!!!
File "/home/lzh/.local/lib/python3.6/site-packages/django/db/backends/mysql/base.py", line 36, in <module> raise ImproperlyConfigured('mysqlclient 1.3.13 or newer is required; you have %s.' % Database.__version__) django.core.exceptions.ImproperlyConfigured: mysqlclient 1.3.13 or newer is required; you have 0.9.3.
6、大部分的人(网上看到的各种笔记,blog,经验分享)都是选择直接跳过这个错误,方法是编辑报错文件:gedit /home/yourusername/.local/lib/python3.6/site-packages/django/db/backends/mysql/base.py
将以下两行注释掉:
# if version < (1, 3, 13): # raise ImproperlyConfigured('mysqlclient 1.3.13 or newer is required; you have %s.' % Database.__version__)
尝试运行runserver或makemigrations,仍然出错:
File "/home/lzh/.local/lib/python3.6/site-packages/django/db/backends/mysql/operations.py", line 146, in last_executed_query query = query.decode(errors='replace') AttributeError: 'str' object has no attribute 'decode'
解决这个报错的方法是:gedit /home/lzh/.local/lib/python3.6/site-packages/django/db/backends/mysql/opetions.py
将decode改为encode,代码为:
def last_executed_query(self, cursor, sql, params): # With MySQLdb, cursor objects have an (undocumented) "_executed" # attribute where the exact query sent to the database is saved. # See MySQLdb/cursors.py in the source distribution. query = getattr(cursor, '_executed', None) if query is not None: query = query.encode(errors='replace') return query
7、后记
安装了MySQL,然后安装了pymysql,就直接开始使用的,当报错时直接使用《6》的方法解决即可,个人怀疑是检查兼容性的代码有bug;
实际上,在bug没有解决前,费劲心思安装mysqlclient一点用处没有!
标签:天坑,mysqlclient,django,报错,mysql,query,安装 来源: https://www.cnblogs.com/lzhshn/p/11439021.html