Chapter 12: Manipulating data
In all previous chapters we’ve been writing SELECT queries. We queried nicely structured data to gether insights, but how this data end up in a database?
Motivation
In real life, you might not always have a nicely structured dataset to work with. Time constraints, new research idea – it means you’ll have to take care of structuring the data yourself.
We’ve already been doing this – every CTE (Common Table Expression aka subquery) is an attempt to structure the data for our research. In the case of a giant unstructured dataset (for example, raw server logs) it’s better to cache a CTE – to save a subquery result set as a proper table.
What you’ll learn
There’re 4 major commands in SQL – SELECT, UPDATE, DELETE and INSERT.
I guess it’s straightforward what each command does. If you already have a nicely structured Data Warehouse at your company, you’ll be writing SELECT queries 99% of the time (the number varies depending on your role, of course).
There’s still this 1% where you need to insert, update or delete records from the database. That’s exactly what you’ll learn in this chapter. Let’s go! 
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1. Adding records to a tableStart
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2. Updating recordsStart
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3. Deleting records from a tableStart
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4. Making subqueries available with VIEWsStart
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5. ETL: Extract, Transform, LoadStart
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6. Manipulating data recapStart
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7. RIGHT JOINStart
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8. Epilogue
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Lessons and exercises
![Anatoli Makarevich, author of SQL Habit]()
About SQL Habit
About SQL Habit
Hi, it’s Anatoli, the author of SQL Habit. 
SQL Habit is a course (or, as some of the students say, “business simulator”). It’s based on a story of a fictional startup called Bindle. You’ll play a role of their Data Analyst 
and solve real-life challenges from Business, Marketing, and Product Management.
SQL Habit course is made of 13 chapters (you’re looking at one atm) that contain 273 bite-sized lessons and exercises. All of them have a real-life setting and detailed explanations. You can immediately apply everything you’ve learned at work.
The 2nd part of the course is called Practice. It’s made of standalone exercises based on multiple datasets – E-commerce, Finance and Meditation app a-la Headspace or Calm. Practice exercises are harder than in the main course. They’ll get you ready for any challenge at work or an interview. 