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Haskell Cookbook

You're reading from   Haskell Cookbook Build functional applications using Monads, Applicatives, and Functors

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Product type Paperback
Published in Sep 2017
Publisher Packt
ISBN-13 9781786461353
Length 396 pages
Edition 1st Edition
Languages
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Author (1):
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Yogesh Sajanikar Yogesh Sajanikar
Author Profile Icon Yogesh Sajanikar
Yogesh Sajanikar
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Table of Contents (13) Chapters Close

Preface 1. Foundations of Haskell FREE CHAPTER 2. Getting Functional 3. Defining Data 4. Working with Functors, Applicatives, and Monads 5. More about Monads 6. Working with Common Containers and Strings 7. Working with Relational and NoSQL Databases 8. Working with HTML and Templates 9. Working with Snap Framework 10. Working with Advanced Haskell 11. Working with Lens and Prism 12. Concurrent and Distributed Programming in Haskell

Managing migrations

When you are working on the databases, and trying to abstract the model on the backend at the same time, you already know that you will need a change in the model, database, or both at some point in time. Catering to changes in the requirements, performance criteria, database schema, or the data model on the backend is inevitable. Changing the database schema without breaking the backend becomes an important and time-consuming task.

In this recipe, we will look at migrations and see how Persistent approaches this issue. We will create a simple model and make a change to the model and run migrations again. We will be using SQLite as the backend.

How to do it...

  1. Create a new project called managing-migrations...
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