Question

我昨天遇到了这个问题，同时尝试使用我在＆＃34;应用SQL转换＆＃34;中使用的相同sqlite脚本。 Azure ML中的模块，Azure ML中的Sqlite over Python模块：

with tbl as (select * from t1)
select * from tbl

这是我得到的错误：

[Critical]     Error: Error 0085: The following error occurred during script evaluation, please view the output log for more information:
---------- Start of error message from Python interpreter ----------
  File "C:\server\invokepy.py", line 169, in batch
data:text/plain,Caught exception while executing function: Traceback (most recent call last):
    odfs = mod.azureml_main(*idfs)
  File "C:\pyhome\lib\site-packages\pandas\io\sql.py", line 388, in read_sql
  File "C:\temp\azuremod.py", line 193, in azureml_main
    results = pd.read_sql(query,con)
    coerce_float=coerce_float, parse_dates=parse_dates)
  File "C:\pyhome\lib\site-packages\pandas\io\sql.py", line 1017, in execute
  File "C:\pyhome\lib\site-packages\pandas\io\sql.py", line 1022, in read_sql
    cursor = self.execute(*args)
    raise_with_traceback(ex)
  File "C:\pyhome\lib\site-packages\pandas\io\sql.py", line 1006, in execute
---------- End of error message from Python  interpreter  ----------
    cur.execute(*args)
DatabaseError: Execution failed on sql:  with tbl as (select * from t1)
                    select * from tbl

和Python代码：

def azureml_main(dataframe1 = None, dataframe2 = None):
    import pandas as pd
    import sqlite3 as lite
    import sys
    con = lite.connect('data1.db')
    con.text_factory = str
    with con:
        cur = con.cursor()

        if (dataframe1 is not None):
            cur.execute("DROP TABLE IF EXISTS t1")
            dataframe1.to_sql('t1',con)
        query = '''with tbl as (select * from t1)
                    select * from tbl'''                      
        results = pd.read_sql(query,con)    

    return results,

用以下代码替换查询时

select * from t1

它按预期工作。正如您可能知道的那样，公用表表达式是Sqlite中的一个关键特性，运行递归代码的能力是“必须具备的”＃34;在任何功能语言中，例如Sqlite。

我还尝试在Azure中的Jupyter Notebook中运行我的Python脚本，该脚本也按预期工作。

我们是否有可能在Python模块中为Sqlite配置不同于Jupyter Notebook和＆＃34;应用SQL转换＆＃34;模块？

Answer 1

我转发了您的问题，并在http://pandas.pydata.org/pandas-docs/stable/io.html#sql-queries审核了SQL Queries pandas.io.sql的{{1}}文档。我尝试使用read_sql_query来解决它，但失败了。

根据pandas doc，似乎Pandas不支持此SQL语法的用法。

根据我的经验并根据您的SQL，我尝试使用SQL select * from (select * from t1) as tbl而不是适用于Pandas的SQL。

希望它有所帮助。最好的祝福。

Azure ML in＆＃34;执行Python脚本＆＃34; module：sqlite3不支持公用表表达式

1 个答案: