December 2017
Beginner
624 pages
15h 38m
Korean
Content preview from Head First Python, 개정판 : 스스로 질문하며 답을 찾는 파이썬 학습서(Python 3)
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458 Chapter 11
문제
데이터베이스의 가용 상태는
언제든 달라질 수 있어요
지금까지
vsearch4web
.
py
코드에서 네 가지 잠재적 문제를 발견했고 그 외에도 숨어 있는
문제가 있을 수 있다는 것을 알았습니다. 우선 발견한 네 가지 잠재적 문제를 하나씩 살펴봅시다.
문제를 해결하는 방법은 뒷부분에서 확인할 겁니다. 우선 백엔드 데이터베이스 문제부터 확인합니다.
데이터베이스 연결에 실패하면 무슨 일이 일어날까요?
우리 웹앱은 천진난만하게 백엔드 데이터베이스를 항상 이용할 수 있다고 가정하고
있습니다. 하지만 여러 가지 이유로 백엔드 데이터베이스 가용 상태는 달라질 수
있습니다. 우리 코드는 데이터베이스 실행이 멈춘 상태를 고려하지 않았으므로 만약
데이터베이스 실행이 멈춘다면 어떤 일이 일어날지 알 수 없습니다.
1
백엔드 데이터베이스 스위치를 끄면 무슨 일이 일어나는지 확인합시다. 아래에서 볼 수 있는
것처럼 웹앱 로드는 문제가 없지만 어떤 동작을 하려 하면 바로 에러 메시지가 나타납니다.
모두
정상으로
보입니다...
...하지만
‘
Do it!
’
버튼을
클릭하면
‘
InterfaceError
’
가
발생하면서 웹앱이
크래시됩니다.
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I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.