Question

我正在尝试运行以下查询。由于某种原因，我需要加入不同的表，其中包括所有表的结果。

假设查询是：

Traceback (most recent call last):
  File "./twitter_scraper.py", line 29, in <module>
    twint_scrape(username, username)
  File "./twitter_scraper.py", line 20, in twint_scrape
    twint.run.Search(c)
  File "C:\Users\seant\Anaconda3\lib\site-packages\twint\run.py", line 201, in Search
    run(config)
  File "C:\Users\seant\Anaconda3\lib\site-packages\twint\run.py", line 153, in run
    get_event_loop().run_until_complete(Twint(config).main())
  File "C:\Users\seant\Anaconda3\lib\asyncio\base_events.py", line 573, in run_until_complete
    return future.result()
  File "C:\Users\seant\Anaconda3\lib\site-packages\twint\run.py", line 121, in main
    await self.tweets()
  File "C:\Users\seant\Anaconda3\lib\site-packages\twint\run.py", line 97, in tweets
    await self.Feed()
  File "C:\Users\seant\Anaconda3\lib\site-packages\twint\run.py", line 40, in Feed
    response = await get.RequestUrl(self.config, self.init, headers=[("User-Agent", self.user_agent)])
  File "C:\Users\seant\Anaconda3\lib\site-packages\twint\get.py", line 58, in RequestUrl
    response = await Request(_url, params=params, connector=_connector, headers=headers)
  File "C:\Users\seant\Anaconda3\lib\site-packages\twint\get.py", line 89, in Request
    return await Response(session, url, params)
  File "C:\Users\seant\Anaconda3\lib\site-packages\twint\get.py", line 94, in Response
    async with session.get(url, ssl=False, params=params) as response:
  File "C:\Users\seant\Anaconda3\lib\site-packages\aiohttp\client.py", line 1005, in __aenter__
    self._resp = await self._coro
  File "C:\Users\seant\Anaconda3\lib\site-packages\aiohttp\client.py", line 497, in _request
    await resp.start(conn)
  File "C:\Users\seant\Anaconda3\lib\site-packages\aiohttp\client_reqrep.py", line 844, in start
    message, payload = await self._protocol.read()  # type: ignore  # noqa
  File "C:\Users\seant\Anaconda3\lib\site-packages\aiohttp\streams.py", line 588, in read
    await self._waiter
aiohttp.client_exceptions.ClientOSError: [WinError 10054] 현재 연결은 원격 호스트에 의해 강제로 끊겼습니다

假设上述查询的结果是：

Select a.value1, b.value2, c.value3 
from a 
join b on a.some_value = b.some_value1 
join c on c.Some_other_value = b.some_diff_value 
where (my conditions)...

我想从上述结果集中删除value1不是1的值。

预期输出：

value1 | value2 | value3  
-------+--------+--------
1      | val1   | val2
1      | some1  | some2
2      | othr1  | othr2
3      | diff2  | diff3

postgresql中有什么方法可以实现这一目标？搜索了不同的主题，但没有其他任何线索。任何建议表示赞赏。

Answer 1

使用子查询，然后在where子句中过滤a.value1=1

select * from
( 
Select a.value1,b.value2,c.value3 
        from a join b on a.some_value=b.some_value1 
        join c on c.Some_othr_value=b.some_diff_value 
    where your conditions
)AA where a.value1=1

从SQL中的结果集中删除一行

1 个答案: