Python Flask Migrate 没有忽略我的模型之外的数据库中的现有表
Python Flask Migrate is not ignoring existing tables in database outside my models
在 link 之后：https://alembic.sqlalchemy.org/en/latest/cookbook.html#don-t-generate-any-drop-table-directives-with-autogenerate 我希望 flask db migrate 忽略应用程序上下文之外的现有 tables，我认为我需要做的就是添加来自 link 的函数并将其设置在上下文中。
这是我的 env.py 文件，但是 flask migrate 仍然出错，因为我的“测试”table 存在于我的数据库中，但不存在于我的模型中：
from __future__ import with_statement
import logging
from logging.config import fileConfig
from flask import current_app
from alembic import context
# this is the Alembic Config object, which provides
# access to the values within the .ini file in use.
config = context.config
# Interpret the config file for Python logging.
# This line sets up loggers basically.
fileConfig(config.config_file_name)
logger = logging.getLogger('alembic.env')
# add your model's MetaData object here
# for 'autogenerate' support
# from myapp import mymodel
# target_metadata = mymodel.Base.metadata
config.set_main_option(
'sqlalchemy.url',
str(current_app.extensions['migrate'].db.get_engine().url).replace(
'%', '%%'))
target_metadata = current_app.extensions['migrate'].db.metadata
# other values from the config, defined by the needs of env.py,
# can be acquired:
# my_important_option = config.get_main_option("my_important_option")
# ... etc.
def run_migrations_offline():
"""Run migrations in 'offline' mode.
This configures the context with just a URL
and not an Engine, though an Engine is acceptable
here as well. By skipping the Engine creation
we don't even need a DBAPI to be available.
Calls to context.execute() here emit the given string to the
script output.
"""
def include_object(object, name, type_, reflected, compare_to):
if type_ == "table" and reflected and compare_to is None:
return False
else:
return True
url = config.get_main_option("sqlalchemy.url")
context.configure(
url=url,
include_object=include_object,
target_metadata=target_metadata,
literal_binds=True
)
with context.begin_transaction():
context.run_migrations()
def run_migrations_online():
"""Run migrations in 'online' mode.
In this scenario we need to create an Engine
and associate a connection with the context.
"""
# this callback is used to prevent an auto-migration from being generated
# when there are no changes to the schema
# reference: http://alembic.zzzcomputing.com/en/latest/cookbook.html
def process_revision_directives(context, revision, directives):
if getattr(config.cmd_opts, 'autogenerate', False):
script = directives[0]
if script.upgrade_ops.is_empty():
directives[:] = []
logger.info('No changes in schema detected.')
def include_object(object, name, type_, reflected, compare_to):
if type_ == "table" and reflected and compare_to is None:
return False
else:
return True
connectable = current_app.extensions['migrate'].db.get_engine()
with connectable.connect() as connection:
context.configure(
include_object=include_object,
connection=connection,
target_metadata=target_metadata,
process_revision_directives=process_revision_directives,
**current_app.extensions['migrate'].configure_args
)
with context.begin_transaction():
context.run_migrations()
if context.is_offline_mode():
run_migrations_offline()
else:
run_migrations_online()
这是运行迁移的脚本：
flask db init || true
flask db migrate -m "db migration."
flask db upgrade
这是错误：
raise exc.NoSuchTableError(table.name)
sqlalchemy.exc.NoSuchTableError: testing
对于遇到此问题的任何其他人，我通过修改 sqlalchemy 解决了它，因为这是抛出错误的原因。 alembic 文档是正确的，但是当 sqlalchemy 抛出 table not found 错误时 alembic 失败。
这些是我的库版本：
Package Version
---------------- -------
alembic 1.6.5
click 8.0.1
Flask 1.1.2
Flask-Migrate 3.0.1
Flask-Script 2.0.6
Flask-SQLAlchemy 2.4.1
greenlet 1.1.0
itsdangerous 2.0.1
Jinja2 3.0.1
Mako 1.1.4
MarkupSafe 2.0.1
pip 19.2.3
psycopg2 2.9.1
python-dateutil 2.8.1
python-editor 1.0.4
setuptools 41.2.0
six 1.16.0
SQLAlchemy 1.4.18
SQLAlchemy-Utils 0.37.7
Werkzeug 2.0.1
如果你打开 reflection.py 文件（位置会有所不同，我的是 lib/python3.8/site-packages/sqlalchemy/engine/reflection.py）并向下滚动并注释掉第 787 行和 788 行，你可以忽略错误：
# Comment these out to perform the migration
# if not found_table:
# raise exc.NoSuchTableError(table.name)
对于我们的应用程序的启动，我们简单地注释掉这些行，运行 迁移，然后用 bash 取消注释它们，不是最干净的但对我们有用：
#!/bin/bash
# Hacky fix to not delete tables outside our application context (i.e tables that arent in our models)
# Comment out when in docker image
if [ ! -z ${MOD_SQLALCHEMY_CODE+x} ]; then
echo "MOD_SQLALCHEMY_CODE is set"
sed -i '/^ if not found_table:/ s/./#&/' /opt/app-root/lib/python3.8/site-packages/sqlalchemy/engine/reflection.py
sed -i '/^ raise exc.NoSuchTableError(table.name)/ s/./#&/' /opt/app-root/lib/python3.8/site-packages/sqlalchemy/engine/changed-reflection.py
else
echo "MOD_SQLALCHEMY_CODE is not set, running with dev configuration."
fi
# Comment out for local dev TODO add in working sed for mac users
# Check to see if we need to do a migration on our database:
echo "Running database migrations."
flask db init || true
chmod 777 /root/jira-app/env.py
cp /root/jira-app/env.py /root/jira-app/migrations/env.py
# incase db needs alembic table < flask db stamp head >
flask db migrate -m "db migration."
flask db upgrade
echo "Database migrations complete."
# undo hacky fix after migrations are completed
if [ ! -z ${MOD_SQLALCHEMY_CODE+x} ]; then
sed -i 's/# if not found_table:/ if not found_table:/g' /opt/app-root/lib/python3.8/site-packages/sqlalchemy/engine/reflection.py
sed -i 's/# raise exc.NoSuchTableError(table.name)/ raise exc.NoSuchTableError(table.name)/g' /opt/app-root/lib/python3.8/site-packages/sqlalchemy/engine/reflection.py
echo "Undoing sqlalchemy code modifications."
fi
我的 env.py 文件有效：
from __future__ import with_statement
import logging
from logging.config import fileConfig
from flask import current_app
from alembic import context
# this is the Alembic Config object, which provides
# access to the values within the .ini file in use.
config = context.config
# Interpret the config file for Python logging.
# This line sets up loggers basically.
fileConfig(config.config_file_name)
logger = logging.getLogger('alembic.env')
# add your model's MetaData object here
# for 'autogenerate' support
# from myapp import mymodel
# target_metadata = mymodel.Base.metadata
config.set_main_option(
'sqlalchemy.url',
str(current_app.extensions['migrate'].db.get_engine().url).replace(
'%', '%%'))
target_metadata = current_app.extensions['migrate'].db.metadata
# other values from the config, defined by the needs of env.py,
# can be acquired:
# my_important_option = config.get_main_option("my_important_option")
# ... etc.
def run_migrations_offline():
"""Run migrations in 'offline' mode.
This configures the context with just a URL
and not an Engine, though an Engine is acceptable
here as well. By skipping the Engine creation
we don't even need a DBAPI to be available.
Calls to context.execute() here emit the given string to the
script output.
"""
url = config.get_main_option("sqlalchemy.url")
context.configure(
url=url, target_metadata=target_metadata, literal_binds=True
)
with context.begin_transaction():
logging.inf(context)
context.run_migrations()
def run_migrations_online():
"""Run migrations in 'online' mode.
In this scenario we need to create an Engine
and associate a connection with the context.
"""
# New Function
def include_object(object, name, type_, reflected, compare_to):
if type_ == "table" and reflected and compare_to is None:
return False
else:
return True
# this callback is used to prevent an auto-migration from being generated
# when there are no changes to the schema
# reference: http://alembic.zzzcomputing.com/en/latest/cookbook.html
def process_revision_directives(context, revision, directives):
if getattr(config.cmd_opts, 'autogenerate', False):
script = directives[0]
if script.upgrade_ops.is_empty():
directives[:] = []
logger.info('No changes in schema detected.')
connectable = current_app.extensions['migrate'].db.get_engine()
with connectable.connect() as connection:
context.configure(
include_object = include_object,
connection=connection,
target_metadata=target_metadata,
process_revision_directives=process_revision_directives,
**current_app.extensions['migrate'].configure_args
)
with context.begin_transaction():
context.run_migrations()
if context.is_offline_mode():
run_migrations_offline()
else:
run_migrations_online()
在 link 之后：https://alembic.sqlalchemy.org/en/latest/cookbook.html#don-t-generate-any-drop-table-directives-with-autogenerate 我希望 flask db migrate 忽略应用程序上下文之外的现有 tables，我认为我需要做的就是添加来自 link 的函数并将其设置在上下文中。
这是我的 env.py 文件，但是 flask migrate 仍然出错，因为我的“测试”table 存在于我的数据库中，但不存在于我的模型中：
from __future__ import with_statement
import logging
from logging.config import fileConfig
from flask import current_app
from alembic import context
# this is the Alembic Config object, which provides
# access to the values within the .ini file in use.
config = context.config
# Interpret the config file for Python logging.
# This line sets up loggers basically.
fileConfig(config.config_file_name)
logger = logging.getLogger('alembic.env')
# add your model's MetaData object here
# for 'autogenerate' support
# from myapp import mymodel
# target_metadata = mymodel.Base.metadata
config.set_main_option(
'sqlalchemy.url',
str(current_app.extensions['migrate'].db.get_engine().url).replace(
'%', '%%'))
target_metadata = current_app.extensions['migrate'].db.metadata
# other values from the config, defined by the needs of env.py,
# can be acquired:
# my_important_option = config.get_main_option("my_important_option")
# ... etc.
def run_migrations_offline():
"""Run migrations in 'offline' mode.
This configures the context with just a URL
and not an Engine, though an Engine is acceptable
here as well. By skipping the Engine creation
we don't even need a DBAPI to be available.
Calls to context.execute() here emit the given string to the
script output.
"""
def include_object(object, name, type_, reflected, compare_to):
if type_ == "table" and reflected and compare_to is None:
return False
else:
return True
url = config.get_main_option("sqlalchemy.url")
context.configure(
url=url,
include_object=include_object,
target_metadata=target_metadata,
literal_binds=True
)
with context.begin_transaction():
context.run_migrations()
def run_migrations_online():
"""Run migrations in 'online' mode.
In this scenario we need to create an Engine
and associate a connection with the context.
"""
# this callback is used to prevent an auto-migration from being generated
# when there are no changes to the schema
# reference: http://alembic.zzzcomputing.com/en/latest/cookbook.html
def process_revision_directives(context, revision, directives):
if getattr(config.cmd_opts, 'autogenerate', False):
script = directives[0]
if script.upgrade_ops.is_empty():
directives[:] = []
logger.info('No changes in schema detected.')
def include_object(object, name, type_, reflected, compare_to):
if type_ == "table" and reflected and compare_to is None:
return False
else:
return True
connectable = current_app.extensions['migrate'].db.get_engine()
with connectable.connect() as connection:
context.configure(
include_object=include_object,
connection=connection,
target_metadata=target_metadata,
process_revision_directives=process_revision_directives,
**current_app.extensions['migrate'].configure_args
)
with context.begin_transaction():
context.run_migrations()
if context.is_offline_mode():
run_migrations_offline()
else:
run_migrations_online()
这是运行迁移的脚本：
flask db init || true
flask db migrate -m "db migration."
flask db upgrade
这是错误：
raise exc.NoSuchTableError(table.name)
sqlalchemy.exc.NoSuchTableError: testing
对于遇到此问题的任何其他人，我通过修改 sqlalchemy 解决了它，因为这是抛出错误的原因。 alembic 文档是正确的，但是当 sqlalchemy 抛出 table not found 错误时 alembic 失败。
这些是我的库版本：
Package Version
---------------- -------
alembic 1.6.5
click 8.0.1
Flask 1.1.2
Flask-Migrate 3.0.1
Flask-Script 2.0.6
Flask-SQLAlchemy 2.4.1
greenlet 1.1.0
itsdangerous 2.0.1
Jinja2 3.0.1
Mako 1.1.4
MarkupSafe 2.0.1
pip 19.2.3
psycopg2 2.9.1
python-dateutil 2.8.1
python-editor 1.0.4
setuptools 41.2.0
six 1.16.0
SQLAlchemy 1.4.18
SQLAlchemy-Utils 0.37.7
Werkzeug 2.0.1
如果你打开 reflection.py 文件（位置会有所不同，我的是 lib/python3.8/site-packages/sqlalchemy/engine/reflection.py）并向下滚动并注释掉第 787 行和 788 行，你可以忽略错误：
# Comment these out to perform the migration
# if not found_table:
# raise exc.NoSuchTableError(table.name)
对于我们的应用程序的启动，我们简单地注释掉这些行，运行 迁移，然后用 bash 取消注释它们，不是最干净的但对我们有用：
#!/bin/bash
# Hacky fix to not delete tables outside our application context (i.e tables that arent in our models)
# Comment out when in docker image
if [ ! -z ${MOD_SQLALCHEMY_CODE+x} ]; then
echo "MOD_SQLALCHEMY_CODE is set"
sed -i '/^ if not found_table:/ s/./#&/' /opt/app-root/lib/python3.8/site-packages/sqlalchemy/engine/reflection.py
sed -i '/^ raise exc.NoSuchTableError(table.name)/ s/./#&/' /opt/app-root/lib/python3.8/site-packages/sqlalchemy/engine/changed-reflection.py
else
echo "MOD_SQLALCHEMY_CODE is not set, running with dev configuration."
fi
# Comment out for local dev TODO add in working sed for mac users
# Check to see if we need to do a migration on our database:
echo "Running database migrations."
flask db init || true
chmod 777 /root/jira-app/env.py
cp /root/jira-app/env.py /root/jira-app/migrations/env.py
# incase db needs alembic table < flask db stamp head >
flask db migrate -m "db migration."
flask db upgrade
echo "Database migrations complete."
# undo hacky fix after migrations are completed
if [ ! -z ${MOD_SQLALCHEMY_CODE+x} ]; then
sed -i 's/# if not found_table:/ if not found_table:/g' /opt/app-root/lib/python3.8/site-packages/sqlalchemy/engine/reflection.py
sed -i 's/# raise exc.NoSuchTableError(table.name)/ raise exc.NoSuchTableError(table.name)/g' /opt/app-root/lib/python3.8/site-packages/sqlalchemy/engine/reflection.py
echo "Undoing sqlalchemy code modifications."
fi
我的 env.py 文件有效：
from __future__ import with_statement
import logging
from logging.config import fileConfig
from flask import current_app
from alembic import context
# this is the Alembic Config object, which provides
# access to the values within the .ini file in use.
config = context.config
# Interpret the config file for Python logging.
# This line sets up loggers basically.
fileConfig(config.config_file_name)
logger = logging.getLogger('alembic.env')
# add your model's MetaData object here
# for 'autogenerate' support
# from myapp import mymodel
# target_metadata = mymodel.Base.metadata
config.set_main_option(
'sqlalchemy.url',
str(current_app.extensions['migrate'].db.get_engine().url).replace(
'%', '%%'))
target_metadata = current_app.extensions['migrate'].db.metadata
# other values from the config, defined by the needs of env.py,
# can be acquired:
# my_important_option = config.get_main_option("my_important_option")
# ... etc.
def run_migrations_offline():
"""Run migrations in 'offline' mode.
This configures the context with just a URL
and not an Engine, though an Engine is acceptable
here as well. By skipping the Engine creation
we don't even need a DBAPI to be available.
Calls to context.execute() here emit the given string to the
script output.
"""
url = config.get_main_option("sqlalchemy.url")
context.configure(
url=url, target_metadata=target_metadata, literal_binds=True
)
with context.begin_transaction():
logging.inf(context)
context.run_migrations()
def run_migrations_online():
"""Run migrations in 'online' mode.
In this scenario we need to create an Engine
and associate a connection with the context.
"""
# New Function
def include_object(object, name, type_, reflected, compare_to):
if type_ == "table" and reflected and compare_to is None:
return False
else:
return True
# this callback is used to prevent an auto-migration from being generated
# when there are no changes to the schema
# reference: http://alembic.zzzcomputing.com/en/latest/cookbook.html
def process_revision_directives(context, revision, directives):
if getattr(config.cmd_opts, 'autogenerate', False):
script = directives[0]
if script.upgrade_ops.is_empty():
directives[:] = []
logger.info('No changes in schema detected.')
connectable = current_app.extensions['migrate'].db.get_engine()
with connectable.connect() as connection:
context.configure(
include_object = include_object,
connection=connection,
target_metadata=target_metadata,
process_revision_directives=process_revision_directives,
**current_app.extensions['migrate'].configure_args
)
with context.begin_transaction():
context.run_migrations()
if context.is_offline_mode():
run_migrations_offline()
else:
run_migrations_online()