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我想用板条箱试一试。我首先通过加载一些 twitter 数据并成功从管理 UI 进行查询来尝试它。但是，当我尝试使用 SQLAlchemy 进行查询时，出现以下错误。

OperationalError: (crate.client.exceptions.ConnectionError) 
No more Servers available, exception from last server: HTTPConnectionPool(host='localhost', port=4200): 
Max retries exceeded with url: 
/_sql (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7f51485b2c18>:
Failed to establish a new connection: [Errno 111] Connection refused'))

[SQL: SELECT * FROM tweets LIMIT 100; ]

(Background on this error at: http://sqlalche.me/e/e3q8)

这是我运行的导致错误的代码。

from crate import client
import sqlalchemy as sa
import pandas as pd

engine = sa.create_engine('crate://localhost:4200')
query = (
            "SELECT * "
            "FROM tweets "
            "LIMIT 100; "
    )
df = pd.read_sql(query, engine)

知道如何修复它（设置都是默认的）？

更新：

Crate 在主机系统上运行，而 Jupyter 在同一台机器上的容器中运行。我可以通过主机上的“ http://localhost:4200 ”访问 Crate，但不能从同一 natwork 中的其他机器执行“ http://xxx.xxx.xxx.xxx:4200 ”。

我都试过了：

engine = sa.create_engine('crate://10.7.116.222:4200')
engine = sa.create_engine('crate://')

这导致了同样的错误：

Removed server http://127.0.0.1:4200 from active pool
Removed server http://127.0.0.1:4200 from active pool

OperationalError: (crate.client.exceptions.ConnectionError) 
No more Servers available, exception from last server: 
HTTPConnectionPool(host='127.0.0.1', port=4200): 
Max retries exceeded with url: 
/_sql (Caused by NewConnectionError('<urllib3.connection.HTTPConnection object at 0x7f5147faaa58>: 
Failed to establish a new connection: [Errno 111] Connection refused'))
[SQL: SELECT * FROM tweets LIMIT 10; ]
(Background on this error at: http://sqlalche.me/e/e3q8)
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1 回答 1

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我还没有尝试过，但根据文档'localhost：4200'假设所以你可以使用只是engine = sa.create_engine('crate://')

于 2019-06-24T00:43:21.013 回答