AttributeError: объект 'int' не имеет атрибута '_compiler_dispatch'

Question

Я использую расширение flask-sqlalchemy с alembic для переноса. Когда я пытаюсь добавить новый файл миграции и обновления схемы до последней один, я получаю следующее сообщение об ошибке:

AttributeError: 'int' object has no attribute '_compiler_dispatch' 

Содержание миграции файла:

revision = 'ec2c2d40eb1' 
down_revision = '28dda873b826' 

from alembic import op 
import sqlalchemy as sa 


def upgrade(): 
    op.alter_column(
     'users', 
     'wiki_permission', 
     new_column_name='wiki_group', 
     nullable=False, 
     existing_nullable=False, 
     type_=sa.Integer(), 
     existing_type=sa.Integer(), 
     server_default=1, 
     existing_server_default=1   # Line of error - 27 
    ) 


def downgrade(): 
    op.alter_column(
     'users', 
     'wiki_group', 
     new_column_name='wiki_permission', 
     nullable=False, 
     existing_nullable=False, 
     type_=sa.Integer(), 
     existing_type=sa.Integer(), 
     server_default=1, 
     existing_server_default=1 
    ) 

Спасибо, что нашли время Помоги мне.

Edit:

Полное сообщение об ошибке:

INFO [alembic.migration] Context impl MySQLImpl. 
INFO [alembic.migration] Will assume non-transactional DDL. 
INFO [alembic.migration] Running upgrade 28dda873b826 -> ec2c2d40eb1, users change column wiki_permission to wiki_group 
Traceback (most recent call last): 
    File "/home/kevin/Code/python/flask/terminus/venv/bin/alembic", line 9, in <module> 
    load_entry_point('alembic==0.6.5', 'console_scripts', 'alembic')() 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/alembic/config.py", line 298, in main 
    CommandLine(prog=prog).main(argv=argv) 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/alembic/config.py", line 293, in main 
    self.run_cmd(cfg, options) 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/alembic/config.py", line 279, in run_cmd 
    **dict((k, getattr(options, k)) for k in kwarg) 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/alembic/command.py", line 125, in upgrade 
    script.run_env() 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/alembic/script.py", line 203, in run_env 
    util.load_python_file(self.dir, 'env.py') 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/alembic/util.py", line 212, in load_python_file 
    module = load_module_py(module_id, path) 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/alembic/compat.py", line 58, in load_module_py 
    mod = imp.load_source(module_id, path, fp) 
    File "alembic/env.py", line 77, in <module> 
    run_migrations_online() 
    File "alembic/env.py", line 70, in run_migrations_online 
    context.run_migrations() 
    File "<string>", line 7, in run_migrations 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/alembic/environment.py", line 688, in run_migrations 
    self.get_context().run_migrations(**kw) 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/alembic/migration.py", line 258, in run_migrations 
    change(**kw) 
    File "alembic/versions/ec2c2d40eb1_users_change_column_wiki_permission_to_.py", line 27, in upgrade 
    existing_server_default=1, 
    File "<string>", line 7, in alter_column 
    File "<string>", line 1, in <lambda> 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/alembic/util.py", line 329, in go 
    return fn(*arg, **kw) 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/alembic/operations.py", line 317, in alter_column 
    existing_autoincrement=existing_autoincrement 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/alembic/ddl/mysql.py", line 44, in alter_column 
    else existing_autoincrement 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/alembic/ddl/impl.py", line 76, in _exec 
    conn.execute(construct, *multiparams, **params) 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 720, in execute 
    return meth(self, multiparams, params) 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/sqlalchemy/sql/ddl.py", line 67, in _execute_on_connection 
    return connection._execute_ddl(self, multiparams, params) 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 768, in _execute_ddl 
    compiled = ddl.compile(dialect=dialect) 
    File "<string>", line 1, in <lambda> 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/sqlalchemy/sql/elements.py", line 468, in compile 
    return self._compiler(dialect, bind=bind, **kw) 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/sqlalchemy/sql/ddl.py", line 25, in _compiler 
    return dialect.ddl_compiler(dialect, self, **kw) 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/sqlalchemy/sql/compiler.py", line 197, in __init__ 
    self.string = self.process(self.statement, **compile_kwargs) 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/sqlalchemy/sql/compiler.py", line 220, in process 
    return obj._compiler_dispatch(self, **kwargs) 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/sqlalchemy/ext/compiler.py", line 410, in <lambda> 
    lambda *arg, **kw: existing(*arg, **kw)) 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/sqlalchemy/ext/compiler.py", line 448, in __call__ 
    return fn(element, compiler, **kw) 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/alembic/ddl/mysql.py", line 171, in _mysql_change_column 
    autoincrement=element.autoincrement 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/alembic/ddl/mysql.py", line 190, in _mysql_colspec 
    spec += " DEFAULT %s" % _render_value(compiler, server_default) 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/alembic/ddl/mysql.py", line 179, in _render_value 
    return compiler.sql_compiler.process(expr) 
    File "/home/kevin/Code/python/flask/terminus/venv/local/lib/python2.7/site-packages/sqlalchemy/sql/compiler.py", line 220, in process 
    return obj._compiler_dispatch(self, **kwargs) 
AttributeError: 'int' object has no attribute '_compiler_dispatch' 

Answer 1

Хорошо, я только что прошел через этот же вопрос. Я не использую фляжку-sqlalchemy, просто прямолинейную, но она должна быть одинаковой.

1. Во-вторых, он работал для меня с sa.Integer без каких-либо скобок, поэтому я бы рекомендовал.

2. alembic docs говорят:

   When producing MySQL-compatible migration files, it is recommended that the existing_type, existing_server_default, and existing_nullable parameters be present, if not being altered.

   Так как кажется, вы не изменения этих столбцов, то документы предполагают, что они должны присутствовать. Итак:

   • Удалить nullable, type_ и server_default. Они не меняются.
   • Удерживать existing_nullable, existing_type и existing_server_default.