[英]Flask-SQLAlchemy create_all()
When i run the dbManager.create_all() command, it runs with out errors but fails to create the tables. 当我运行dbManager.create_all()命令时,它运行时没有错误但无法创建表。 When i delete the database and run the create_all() command, i get the no such database as ##### error which i should get but when the database does exist, nothing happens.
当我删除数据库并运行create_all()命令时,我得到没有这样的数据库作为#####错误我应该得到但是当数据库确实存在时,没有任何反应。 Please can anyone see what i'm doing wrong?
请任何人都能看到我做错了什么?
from blogconfig import dbManager
class Art(dbManager.Model):
id = dbManager.Column(dbManager.Integer, primary_key = True)
title = dbManager.Column(dbManager.String(64), index = True, unique = True)
content = dbManager.Column(dbManager.Text(5000))
def __repr__(self):
return '<Art %r>' %(self.title)
EDIT This is the shell command 编辑这是shell命令
from blogconfig import dbManager
>>> dbManager.create_all()
import models
>>> a = models.Art(title='des', content='asdfvhbdjbjdn')
>>> dbManager.session.add(a)
>>> dbManager.session.commit()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/scoping.py", line 149, in do
return getattr(self.registry(), name)(*args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 721, in commit
self.transaction.commit()
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 354, in commit
self._prepare_impl()
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 334, in _prepare_impl
self.session.flush()
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 1818, in flush
self._flush(objects)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 1936, in _flush
transaction.rollback(_capture_exception=True)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/util/langhelpers.py", line 58, in __exit__
compat.reraise(exc_type, exc_value, exc_tb)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 1900, in _flush
flush_context.execute()
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/unitofwork.py", line 372, in execute
rec.execute(self)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/unitofwork.py", line 525, in execute
uow
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/persistence.py", line 64, in save_obj
table, insert)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/persistence.py", line 569, in _emit_insert_statements
execute(statement, params)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 662, in execute
params)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 761, in _execute_clauseelement
compiled_sql, distilled_params
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 874, in _execute_context
context)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1024, in _handle_dbapi_exception
exc_info
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/util/compat.py", line 195, in raise_from_cause
reraise(type(exception), exception, tb=exc_tb)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 867, in _execute_context
context)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/default.py", line 324, in do_execute
cursor.execute(statement, parameters)
File "/usr/lib/python2.7/dist-packages/MySQLdb/cursors.py", line 174, in execute
self.errorhandler(self, exc, value)
File "/usr/lib/python2.7/dist-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler
raise errorclass, errorvalue
sqlalchemy.exc.ProgrammingError: (ProgrammingError) (1146, "Table 'blog.art' doesn't exist") 'INSERT INTO art (title, content) VALUES (%s, %s)' ('des', 'asdfvhbdjbjdn')
dbManager will not know about the models you define in other modules unless they are imported before running create_all
. dbManager不会知道您在其他模块中定义的模型,除非在运行
create_all
之前导入它们。
In a real application this shouldn't matter because running the flask app should set up the db and import views/blueprints to register them. 在实际的应用程序中,这应该无关紧要,因为运行烧瓶应用程序应该设置db并导入视图/蓝图以注册它们。 Since the views use the models, the models are indirectly imported and are available to the dbManager.
由于视图使用模型,因此模型是间接导入的,并且可供dbManager使用。
Either import your models in the blogconfig
module after creating the dbManager instance, or change the order of you shell commands to be 在创建dbManager实例后,在
blogconfig
模块中导入模型,或者更改shell命令的顺序
>>> from blogconfig import dbManager
>>> import models
>>> dbManager.create_all()
SQLAlchemy will only create tables, the database must already exist, which is why you're seeing the other error when you delete the database. SQLAlchemy只会创建表,数据库必须已经存在,这就是删除数据库时看到其他错误的原因。
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