September 2017
Beginner to intermediate
396 pages
9h 46m
English
Content preview from Haskell Cookbook
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Using Esqueleto to do advanced SQL queries
We have used the Persistent library and SQL expressions using the Database.Persist.SQL module. We have used the generated types for each field in the filter, insert, and update expressions. But the complexity of the query can increase rapidly. Of course, there is a way to do a plain SQL query with the persistent library. Here, in this recipe, we will be using the Esqueleto library to do complex queries such as joins.
In this recipe, we will write a complex SQL query that is type-safe and easy to write. Being type-safe is good, because we will catch any major issues earlier on!
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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.