June 2010
Intermediate to advanced
328 pages
7h 51m
English
Content preview from SQL Antipatterns
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Chapter 3Naive Trees
A tree is a tree—how many more do you need to look at?
Ronald Reagan
Suppose you work as a software developer for a famous website for science and technology news.
This is a modern website, so readers can contribute comments and even reply to each other, forming threads of discussion that branch and extend deeply. You choose a simple solution to track these reply chains: each comment references the comment to which it replies.
| Trees/intro/parent.sql | |
| | CREATE TABLE Comments ( |
| | comment_id SERIAL PRIMARY KEY, |
| | parent_id BIGINT UNSIGNED, |
| | comment TEXT NOT NULL, |
| | FOREIGN KEY (parent_id) REFERENCES Comments(comment_id) |
| | ); |
It soon becomes clear, however, that it’s hard to retrieve a long chain of replies ...
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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.
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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.