问题
I have been trying this problem for a very long time. But I just cannot seem to find the solution. I am trying to deploy my project on pythonanywhere, where I have chosen MySQL. Whenever I try to migrate my models with python manage.py migrate. I get the following error:
This is my models.
models.py
from django.db import models
from django.contrib.auth.models import User
# Create your models here.
class Thing(models.Model):
thing_name = models.CharField(max_length=64, unique=True)
def __str__(self):
return self.hobby_name
class Person(models.Model):
user = models.OneToOneField(
User,
on_delete=models.CASCADE,
)
first_name = models.CharField(max_length=64, null=True, blank=False)
last_name = models.CharField(max_length=64, null=True, blank=False)
hobbies = models.ManyToManyField(Hobby, blank=False)
email = models.EmailField(max_length=64, blank=True, null=True, unique=True)
city = models.CharField(max_length=64, null=True, blank=False)
zip_code = models.CharField(max_length=10, null=True, blank=False)
description = models.TextField(max_length=2048, null=True, blank=True)
gender = models.CharField(max_length=1,
choices=(
('N', 'No answer'),
('M', 'Male'),
('F', 'Female'),
('O', 'Other')
), null=True, blank=True, default="N"
)
bad = models.BooleanField(default=False)
good = models.BooleanField(default=True)
maximum_hours = models.PositiveIntegerField(default=2)
def __str__(self):
try:
string = self.first_name + " " + self.last_name
except:
string = "name_error"
return string
Last note is that I have DROPPED and re-CREATED the database several times. Each time by:
CREATE DATABASE database_name DEFAULT CHARACTER SET utf8 DEFAULT COLLATE utf8_general_ci;
I am deploying all of this to Pythonanywhere.
The model Thing actually becomes a table. But the model Person does not.
Edit: Here is the full traceback
(hobbyin) 01:16 ~/hobbyin (master)$ python manage.py migrate
System check identified some issues:
WARNINGS:
?: (mysql.W002) MySQL Strict Mode is not set for database connection 'default'
HINT: MySQL's Strict Mode fixes many data integrity problems in MySQL, such as data truncation upon insertion, by escalating warnings into errors. It
is strongly recommended you activate it. See: https://docs.djangoproject.com/en/2.0/ref/databases/#mysql-sql-mode
Operations to perform:
Apply all migrations: account, admin, auth, contenttypes, external_page, sessions, sites, socialaccount
Running migrations:
Applying contenttypes.0001_initial... OK
Applying auth.0001_initial... OK
Applying account.0001_initial... OK
Applying account.0002_email_max_length... OK
Applying admin.0001_initial... OK
Applying admin.0002_logentry_remove_auto_add... OK
Applying contenttypes.0002_remove_content_type_name... OK
Applying auth.0002_alter_permission_name_max_length... OK
Applying auth.0003_alter_user_email_max_length... OK
Applying auth.0004_alter_user_username_opts... OK
Applying auth.0005_alter_user_last_login_null... OK
Applying auth.0006_require_contenttypes_0002... OK
Applying auth.0007_alter_validators_add_error_messages... OK
Applying auth.0008_alter_user_username_max_length... OK
Applying auth.0009_alter_user_last_name_max_length... OK
Applying external_page.0001_initial...Traceback (most recent call last):
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/db/backends/utils.py", line 83, in _execute
return self.cursor.execute(sql)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/db/backends/mysql/base.py", line 71, in execute
return self.cursor.execute(query, args)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/MySQLdb/cursors.py", line 250, in execute
self.errorhandler(self, exc, value)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/MySQLdb/connections.py", line 50, in defaulterrorhandler
raise errorvalue
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/MySQLdb/cursors.py", line 247, in execute
res = self._query(query)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/MySQLdb/cursors.py", line 412, in _query
rowcount = self._do_query(q)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/MySQLdb/cursors.py", line 375, in _do_query
db.query(q)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/MySQLdb/connections.py", line 276, in query
_mysql.connection.query(self, query)
_mysql_exceptions.OperationalError: (1071, 'Specified key was too long; max key length is 767 bytes')
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "manage.py", line 15, in <module>
execute_from_command_line(sys.argv)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/core/management/__init__.py", line 371, in execute_from_command_line
utility.execute()
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/core/management/__init__.py", line 365, in execute
self.fetch_command(subcommand).run_from_argv(self.argv)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/core/management/base.py", line 288, in run_from_argv
self.execute(*args, **cmd_options)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/core/management/base.py", line 335, in execute
output = self.handle(*args, **options)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/core/management/commands/migrate.py", line 200, in handle
fake_initial=fake_initial,
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/db/migrations/executor.py", line 117, in migrate
state = self._migrate_all_forwards(state, plan, full_plan, fake=fake, fake_initial=fake_initial)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/db/migrations/executor.py", line 147, in _migrate_all_forwards
state = self.apply_migration(state, migration, fake=fake, fake_initial=fake_initial)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/db/migrations/executor.py", line 244, in apply_migration
state = migration.apply(state, schema_editor)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/db/migrations/migration.py", line 122, in apply
operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/db/migrations/operations/models.py", line 92, in database_forwards
schema_editor.create_model(model)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/db/backends/base/schema.py", line 314, in create_model
self.execute(sql, params or None)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/db/backends/base/schema.py", line 133, in execute
cursor.execute(sql, params)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/db/backends/utils.py", line 68, in execute
return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/db/backends/utils.py", line 77, in _execute_with_wrappers
return executor(sql, params, many, context)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/db/backends/utils.py", line 85, in _execute
return self.cursor.execute(sql, params)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/db/utils.py", line 89, in __exit__
raise dj_exc_value.with_traceback(traceback) from exc_value
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/db/backends/utils.py", line 83, in _execute
return self.cursor.execute(sql)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/django/db/backends/mysql/base.py", line 71, in execute
return self.cursor.execute(query, args)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/MySQLdb/cursors.py", line 250, in execute
self.errorhandler(self, exc, value)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/MySQLdb/connections.py", line 50, in defaulterrorhandler
raise errorvalue
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/MySQLdb/cursors.py", line 247, in execute
res = self._query(query)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/MySQLdb/cursors.py", line 412, in _query
rowcount = self._do_query(q)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/MySQLdb/cursors.py", line 375, in _do_query
db.query(q)
File "/home/maxxie/.virtualenvs/hobbyin/lib/python3.6/site-packages/MySQLdb/connections.py", line 276, in query
_mysql.connection.query(self, query)
django.db.utils.OperationalError: (1071, 'Specified key was too long; max key length is 767 bytes')
回答1:
Found the answer. When you deploy your code to production. Make sure that your migration files are removed. Otherwise it might cause unexpected errors such as this one.
来源：https://stackoverflow.com/questions/51334487/django-deploying-on-mysql-gives-1071-error-specified-key-was-too-long