Erreur 500 à la connexion

[christophe]

Je viens de supprimer les tables pour refaire une migration

Code :

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/2.2/ref/databases/#mysql-sql-mode
Operations to perform:
 Apply all migrations: activities, assistants, auth, billing, commercial, contenttypes, creme_config, creme_core, crudity, documents, emails, events, geolocation, graphs, opportunities, persons, products, projects, recurrents, reports, sessions, tickets
Running migrations:
 Applying creme_core.0001_initial...Traceback (most recent call last):
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/db/backends/utils.py", line 82, in _execute
   return self.cursor.execute(sql)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/db/backends/mysql/base.py", line 71, in execute
   return self.cursor.execute(query, args)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/MySQLdb/cursors.py", line 209, in execute
   res = self._query(query)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/MySQLdb/cursors.py", line 315, in _query
   db.query(q)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/MySQLdb/connections.py", line 239, in query
   _mysql.connection.query(self, query)
MySQLdb._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 10, in <module>
   execute_from_command_line(sys.argv)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/core/management/__init__.py", line 381, in execute_from_command_line
   utility.execute()
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/core/management/__init__.py", line 375, in execute
   self.fetch_command(subcommand).run_from_argv(self.argv)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/core/management/base.py", line 323, in run_from_argv
   self.execute(*args, **cmd_options)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/core/management/base.py", line 364, in execute
   output = self.handle(*args, **options)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/core/management/base.py", line 83, in wrapped
   res = handle_func(*args, **kwargs)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/core/management/commands/migrate.py", line 234, in handle
   fake_initial=fake_initial,
 File "/home/cintranet/venv_creme/lib/python3.5/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/cintranet/venv_creme/lib/python3.5/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/cintranet/venv_creme/lib/python3.5/site-packages/django/db/migrations/executor.py", line 245, in apply_migration
   state = migration.apply(state, schema_editor)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/db/migrations/migration.py", line 124, in apply
   operation.database_forwards(self.app_label, schema_editor, old_state, project_state)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/db/migrations/operations/models.py", line 92, in database_forwards
   schema_editor.create_model(model)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/db/backends/base/schema.py", line 307, in create_model
   self.execute(sql, params or None)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/db/backends/base/schema.py", line 137, in execute
   cursor.execute(sql, params)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/db/backends/utils.py", line 67, in execute
   return self._execute_with_wrappers(sql, params, many=False, executor=self._execute)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/db/backends/utils.py", line 76, in _execute_with_wrappers
   return executor(sql, params, many, context)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/db/backends/utils.py", line 84, in _execute
   return self.cursor.execute(sql, params)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/db/utils.py", line 89, in __exit__
   raise dj_exc_value.with_traceback(traceback) from exc_value
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/db/backends/utils.py", line 82, in _execute
   return self.cursor.execute(sql)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/django/db/backends/mysql/base.py", line 71, in execute
   return self.cursor.execute(query, args)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/MySQLdb/cursors.py", line 209, in execute
   res = self._query(query)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/MySQLdb/cursors.py", line 315, in _query
   db.query(q)
 File "/home/cintranet/venv_creme/lib/python3.5/site-packages/MySQLdb/connections.py", line 239, in query
   _mysql.connection.query(self, query)
django.db.utils.OperationalError: (1071, 'Specified key was too long; max key length is 767 bytes')

je suis sur Maria DB

merci pour votre aide
Christophe