我正在使用dataset库尝试将postgres数据库备份到sqlite文件中。我运行的代码如下:
local_db = "sqlite:///backup_file.db"
with dataset.connect(local_db) as save_to:
with dataset.connect(postgres_db) as download_from:
for row in download_from['outlook']:
save_to['outlook'].insert(row)
如果打印表中的一行,则如下所示:
^{pr2}$但是,当我到达save_to['outlook'].insert(row)
行时,我得到一个错误,其中包含以下堆栈跟踪:
Traceback (most recent call last):
File "/home/anton/Development/Python/TTC/backup_db.py", line 25, in <module>
save_to['outlook'].insert(dict(row))
File "/home/anton/.virtualenvs/flexity/lib/python3.6/site-packages/dataset/table.py", line 79, in insert
row = self._sync_columns(row, ensure, types=types)
File "/home/anton/.virtualenvs/flexity/lib/python3.6/site-packages/dataset/table.py", line 278, in _sync_columns
self._sync_table(sync_columns)
File "/home/anton/.virtualenvs/flexity/lib/python3.6/site-packages/dataset/table.py", line 245, in _sync_table
self._table.append_column(column)
File "/home/anton/.virtualenvs/flexity/lib/python3.6/site-packages/sqlalchemy/sql/schema.py", line 681, in append_column
column._set_parent_with_dispatch(self)
File "/home/anton/.virtualenvs/flexity/lib/python3.6/site-packages/sqlalchemy/sql/base.py", line 431, in _set_parent_with_dispatch
self._set_parent(parent)
File "/home/anton/.virtualenvs/flexity/lib/python3.6/site-packages/sqlalchemy/sql/schema.py", line 1344, in _set_parent
self.key, table.fullname))
sqlalchemy.exc.ArgumentError: Trying to redefine primary-key column 'id' as a non-primary-key column on table 'outlook'
你知道我做错了什么吗?我已经在python2.7.14和3.6.3中尝试过这种方法
假设您有一个为“outlook”创建的架构和表,那么您是否创建了PK字段?你让sqlite决定哪个字段组成PK字段了吗?在
你试图插入id两次是非常重要的。一旦sqlite插入了自己,其他的则来自其他表记录。在
我想出来了!所以,诀窍在于,默认情况下,
database
库生成具有自动递增整数主键的表。但是,我的数据已经有一个'id'列。为了避免这个问题,我应该在尝试向表中添加行之前定义表,并且定义它时不使用主键,如下所示:通过执行
.create_table(table_name, primary_key=False)
操作,我可以确保可以在表中插入我自己的id值。在我通过reading the docs找到了这个解决方案。在
相关问题 更多 >
编程相关推荐