当我试图从Django默认使用的SQLite数据库更改为MySQL数据库时,运行python manage.py migrate --database mysql
时遇到了这个棘手的错误:
Traceback (most recent call last):
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/backends/mysql/base.py", line 15, in <module>
import MySQLdb as Database
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/MySQLdb/__init__.py", line 18, in <module>
import _mysql
ImportError: dlopen(/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/_mysql.cpython-37m-darwin.so, 2): Library not loaded: @rpath/libmysqlclient.21.dylib
Referenced from: /Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/_mysql.cpython-37m-darwin.so
Reason: image not found
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "manage.py", line 20, in <module>
execute_from_command_line( sys.argv )
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/__init__.py", line 381, in execute_from_command_line
utility.execute()
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/__init__.py", line 375, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/base.py", line 316, in run_from_argv
self.execute(*args, **cmd_options)
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/base.py", line 350, in execute
self.check()
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/base.py", line 379, in check
include_deployment_checks=include_deployment_checks,
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/commands/migrate.py", line 59, in _run_checks
issues = run_checks(tags=[Tags.database])
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/checks/registry.py", line 71, in run_checks
new_errors = check(app_configs=app_configs)
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/checks/database.py", line 9, in check_database_backends
for conn in connections.all():
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/utils.py", line 217, in all
return [self[alias] for alias in self]
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/utils.py", line 217, in <listcomp>
return [self[alias] for alias in self]
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/utils.py", line 202, in __getitem__
backend = load_backend(db['ENGINE'])
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/utils.py", line 110, in load_backend
return import_module('%s.base' % backend_name)
File "/usr/local/Cellar/python/3.7.0/Frameworks/Python.framework/Versions/3.7/lib/python3.7/importlib/__init__.py", line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
File "<frozen importlib._bootstrap>", line 983, in _find_and_load
File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 728, in exec_module
File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/backends/mysql/base.py", line 20, in <module>
) from err
django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module.
Did you install mysqlclient?
我已经通过pip install mysqlclient
安装了mysqlclient,并通过Homebrew使用brew install mysql-connector-c
安装了它的连接器,但仍然收到了这个错误。即使按照连接器说明修改了连接器bin文件夹中的mysql_config
文件,我仍然遇到了这个问题。鉴于这个连接器已知的bug文档,这似乎与我正在运行的macOS有关。
进一步检查我的堆栈跟踪后,我注意到顶部出现了Library not loaded: @rpath/libmysqlclient.21.dylib
错误。紧接着是另一个可能的线索:Reason: image not found
,但我不确定这是什么意思。
我在/usr/local/Cellar/mysql-connector-c
中查看了一下我安装的连接器是否有什么可能丢失的东西,果然,libmysqlclient.21.dylib
文件丢失了。取而代之的是我认为是旧版本的文件,因为它被命名为libmysqlclient.18.dylib
。出于好奇,我复制了MySQL安装所带的.dylib
并将该副本移动到相同名称的连接器文件夹和/usr/local/lib
,在那里我还找到了另一个libmysqlclient.18.dylib
文件。然而,我的迁移仍然失败了,但我确实得到了稍微不同的堆栈跟踪:
Traceback (most recent call last):
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/backends/mysql/base.py", line 15, in <module>
import MySQLdb as Database
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/MySQLdb/__init__.py", line 18, in <module>
import _mysql
ImportError: dlopen(/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/_mysql.cpython-37m-darwin.so, 2): Library not loaded: @rpath/libmysqlclient.21.dylib
Referenced from: /Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/_mysql.cpython-37m-darwin.so
Reason: no suitable image found. Did find:
/usr/local/lib/libmysqlclient.21.dylib: file too short
/usr/local/lib/libmysqlclient.21.dylib: file too short
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "manage.py", line 20, in <module>
execute_from_command_line( sys.argv )
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/__init__.py", line 381, in execute_from_command_line
utility.execute()
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/__init__.py", line 375, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/base.py", line 316, in run_from_argv
self.execute(*args, **cmd_options)
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/base.py", line 350, in execute
self.check()
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/base.py", line 379, in check
include_deployment_checks=include_deployment_checks,
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/management/commands/migrate.py", line 59, in _run_checks
issues = run_checks(tags=[Tags.database])
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/checks/registry.py", line 71, in run_checks
new_errors = check(app_configs=app_configs)
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/core/checks/database.py", line 9, in check_database_backends
for conn in connections.all():
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/utils.py", line 217, in all
return [self[alias] for alias in self]
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/utils.py", line 217, in <listcomp>
return [self[alias] for alias in self]
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/utils.py", line 202, in __getitem__
backend = load_backend(db['ENGINE'])
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/utils.py", line 110, in load_backend
return import_module('%s.base' % backend_name)
File "/usr/local/Cellar/python/3.7.0/Frameworks/Python.framework/Versions/3.7/lib/python3.7/importlib/__init__.py", line 127, in import_module
return _bootstrap._gcd_import(name[level:], package, level)
File "<frozen importlib._bootstrap>", line 1006, in _gcd_import
File "<frozen importlib._bootstrap>", line 983, in _find_and_load
File "<frozen importlib._bootstrap>", line 967, in _find_and_load_unlocked
File "<frozen importlib._bootstrap>", line 677, in _load_unlocked
File "<frozen importlib._bootstrap_external>", line 728, in exec_module
File "<frozen importlib._bootstrap>", line 219, in _call_with_frames_removed
File "/Users/xoadra/Programming/Syntax/Python/Environments/pfitzer/lib/python3.7/site-packages/django/db/backends/mysql/base.py", line 20, in <module>
) from err
django.core.exceptions.ImproperlyConfigured: Error loading MySQLdb module.
Did you install mysqlclient?
这次我遇到了以下错误:
Reason: no suitable image found. Did find:
/usr/local/lib/libmysqlclient.21.dylib: file too short
/usr/local/lib/libmysqlclient.21.dylib: file too short
因此,我怀疑问题可能与MySQL连接器安装的.dylib
版本有关,但我不确定如何确切地解决这个问题。我发现仅仅复制一个文件就能微调我的堆栈跟踪,所以我想我应该更深入地研究一下这个问题。你有什么想法吗?
sudo ln -s /usr/local/mysql-8.0.19-macos10.15-x86_64/lib/libmysqlclient.21.dylib /usr/local/lib/libmysqlclient.21.dylib
。 - Ziyad Sfaxi