Why You Should Learn SQL

eilert - 2020-01-21 00:00:00.00

To Get Answers

SQL is how you interact with data.
Data answers questions.
So if you want to answer questions, you'll need to look at data, and SQL will help you do that.

Of course you may have some reports to get your data, but what happens if you want to know some metric that isn't in any existing report?

For example, maybe I'm curious to know (roughly) the average number of words in the blog posts on this site and that doesn't happen to exist in any report.

SELECT AVG(LEN(content) - LEN(REPLACE(content, ' ', ''))) FROM posts

Done.

Well to be honest, there are some flaws with that so it's not 100%, but it does give a rough idea.

"I Already Know SQL"

A little or a lot?

When I say "learn SQL" I don't mean

SELECT first_name, last_name FROM users WHERE id = 123;

I mean...
(complex query with cross join and left join recursive cte and window function)
LIKE with basic regular expression?

Everything Is Data

Seriously.

How many blog posts a month?
5 Tallest buildings in each major city?
HTML markup is data a browser uses to render a web page. Same with the css in it.
Process duration trends over time.
How many third party cookies are on that site?
A letter's ASCII code.
The way you tie your shoelaces. Standard or two loop? what percent of people might do it some other way? It's data.

How Can I Learn SQL?

There are a ton of resources out there, but of course the teacher is experience. Think of different ways you'd like to look at data and figure out how to write a query to do that.
Remember: you can probably do that in SQL.

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