March 2016
Beginner
414 pages
9h 29m
English
Content preview from Learning PHP 7Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
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Joining tables
Even though querying MySQL is quite fast, especially if it is in the same server as our PHP application, we should try to reduce the number of queries that we will execute to improve the performance of our application. So far, we have queried data from just one table, but this is rarely the case. Imagine that you want to retrieve information about borrowed books: the table contains only IDs and dates, so if you query it, you will not get very meaningful data, right? One approach would be to query the data in borrowed_books, and based on the returning IDs, query the book and customer tables by filtering by the IDs we are interested in. However, this approach consists of at least three queries to MySQL and a lot of work with arrays ...
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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.
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.