pymysql 查询：无法回滚

Question

连接没问题，但是查询语句好像有问题

query1 = """SELECT * FROM `DATABASE` WHERE `coin` = 'LTC'"""
query2 = """SELECT * FROM `DATABASE` WHERE `coin` = 'LTC' AND `date` > '2019-01-01 15:06:23'"""

然后

import pandas as pd    
result = pd.read_sql(query, connection)

它在 query1 上工作得很好，但在 query2 上出现这样的错误：结果 = pd.read_sql（查询，连接）

Traceback (most recent call last):

  File "<ipython-input-25-c7c27cfd9a6b>", line 1, in <module>
    result = pd.read_sql(query, connection)

  File "C:\Users\luzhe\Anaconda3\lib\site-packages\pandas\io\sql.py", line 381, in read_sql
    chunksize=chunksize)

  File "C:\Users\luzhe\Anaconda3\lib\site-packages\pandas\io\sql.py", line 1413, in read_query
    cursor = self.execute(*args)

  File "C:\Users\luzhe\Anaconda3\lib\site-packages\pandas\io\sql.py", line 1386, in execute
    raise_with_traceback(ex)

  File "C:\Users\luzhe\Anaconda3\lib\site-packages\pandas\compat\__init__.py", line 404, in raise_with_traceback
    raise exc.with_traceback(traceback)

  File "C:\Users\luzhe\Anaconda3\lib\site-packages\pandas\io\sql.py", line 1382, in execute
    self.con.rollback()

  File "C:\Users\luzhe\Anaconda3\lib\site-packages\pymysql\connections.py", line 808, in rollback
    self._execute_command(COMMAND.COM_QUERY, "ROLLBACK")

  File "C:\Users\luzhe\Anaconda3\lib\site-packages\pymysql\connections.py", line 1122, in _execute_command
    raise err.InterfaceError("(0, '')")

DatabaseError: Execution failed on sql: SELECT * FROM `DATABASE` WHERE `coin` = 'LTC' AND `date` > '2019-01-01 15:06:23'
(0, '')
unable to rollback

我想知道这个"unable to rollback"是什么意思以及如何在PyMySQL中解决这个多条件选择

Answer 1

unable to rollback

表示您的查询没有成功执行。

未关闭的连接通常是该错误的原因。您可能没有关闭以前的连接。您通常可以使用与连接实例关联的 close 方法来执行此操作。

pymysql 查询：无法回滚

pymysql query : unable to rollback

mysql

sql

python-3.x

pandas

pymysql