June 2010
Intermediate to advanced
328 pages
7h 51m
English
Content preview from SQL Antipatterns
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Chapter 6Entity-Attribute-Value
If you try and take a cat apart to see how it works, the first thing you have in your hands is a non-working cat.
Douglas Adams
“How do I count the number of rows by date?” This is an example of a simple task for a database programmer. This solution is covered in any introductory tutorial on SQL. It involves basic SQL syntax:
| EAV/intro/count.sql | |
| | SELECT date_reported, COUNT(*) |
| | FROM Bugs |
| | GROUP BY date_reported; |
However, the simple solution assumes two things:
-
Values are stored in the same column, as in Bugs.date_reported.
-
Values can be compared to one another so that GROUP BY can accurately group dates with equal values together.
What if you can’t rely on those assumptions? What if the date ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
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.