jupyter 笔记本中的 SQL 魔法

Question

我是 Jupyter Notebook 的新手，但想学习它。目前我正在尝试使用 sql magic 进行一些基本的数据库操作。我可以建立连接并创建一个新表。但是当我尝试读出该表时，会发生此非特定错误。有人可以帮我吗？

我的“代码”：

1. 正在加载东西：

import sys
print(sys.executable)
from sqlalchemy.engine import create_engine
import pandas as pd
%load_ext sql

#setup database connection
%sql postgresql://postgres:postgres@localhost:5432/rain

2. 创建表：

%%sql
CREATE TABLE people (first text, last text, drink text);
INSERT INTO people (first,last,drink)
VALUES
    ('zaphod','beeblebrox','pan galactic gargle blaster'),
    ('arthur','dent','tea'),
    ('ford','prefect','old janx spirit')
    ;

3. 试图拿到桌子：

%sql select * from people;

错误：

---------------------------------------------------------------------------
KeyError                                  Traceback (most recent call last)
Cell In[40], line 1
----> 1 get_ipython().run_cell_magic('sql', '', '\nselect * from people;\n')

File ~/.local/share/pipx/venvs/jupyterlab/lib/python3.12/site-packages/IPython/core/interactiveshell.py:2541, in InteractiveShell.run_cell_magic(self, magic_name, line, cell)
   2539 with self.builtin_trap:
   2540     args = (magic_arg_s, cell)
-> 2541     result = fn(*args, **kwargs)
   2543 # The code below prevents the output from being displayed
   2544 # when using magics with decorator @output_can_be_silenced
   2545 # when the last Python token in the expression is a ';'.
   2546 if getattr(fn, magic.MAGIC_OUTPUT_CAN_BE_SILENCED, False):

File ~/.local/share/pipx/venvs/jupyterlab/lib/python3.12/site-packages/sql/magic.py:219, in SqlMagic.execute(self, line, cell, local_ns)
    216     return
    218 try:
--> 219     result = sql.run.run(conn, parsed["sql"], self, user_ns)
    221     if (
    222         result is not None
    223         and not isinstance(result, str)
   (...)
    226         # Instead of returning values, set variables directly in the
    227         # user's namespace. Variable names given by column names
    229         if self.autopandas:

File ~/.local/share/pipx/venvs/jupyterlab/lib/python3.12/site-packages/sql/run.py:374, in run(conn, sql, config, user_namespace)
    372     if result and config.feedback:
    373         print(interpret_rowcount(result.rowcount))
--> 374 resultset = ResultSet(result, config)
    375 if config.autopandas:
    376     return resultset.DataFrame()

File ~/.local/share/pipx/venvs/jupyterlab/lib/python3.12/site-packages/sql/run.py:116, in ResultSet.__init__(self, sqlaproxy, config)
    114         list.__init__(self, sqlaproxy.fetchall())
    115     self.field_names = unduplicate_field_names(self.keys)
--> 116     self.pretty = PrettyTable(self.field_names, style=prettytable.__dict__[config.style.upper()])
    117 else:
    118     list.__init__(self, [])

KeyError: 'DEFAULT'

Answer 1

从日志消息来看，prettyTable 抛出错误，可能与结果的呈现方式有关。 尝试设置此选项，这将以纯文本格式返回结果。

%config SqlMagic.style = 'PLAIN'

也尝试为 PrettyTable 设置此项

%config SqlMagic.style = 'DEFAULT'