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Learn SQL Once, Use It for 30 Years

86 pointsby karakoramlast Sunday at 5:16 PM47 commentsview on HN

Comments

wodenokototoday at 9:09 AM

I think the pretext of this articles is ridiculous.

Yes, SQL is based around relational algebra, but all programming languages are built on a theoretical foundation.

And SQL is very much a "fad" language - it just somehow managed to stick around. The goal was not some sort of mathematical purity, but rather to built a natural language data interface (sounds like something currently very hyped?) and it failed spectacularly at that goal.

It is so far from natural language that English speakers with statistical understanding won't be able to read it, but it is also inconsistent enough in its grammar design that it is unreasonably difficult to learn and needs large refactoring every time you want to query into the result of a query.

To continue my rant: Sometimes '=' is an identity test, sometimes it is `==`. Sometimes groups are called groups, sometimes they are partitions.

When creating a CTE, you put the name before "AS", but when creating a column, you put the name after "AS".

SQL is great because it is everywhere and it is definitely good enough, but it is not something great, that transcends other programming languages.

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gobdovantoday at 9:20 AM

> The Only Programming Language Built on Mathematics, Not Fashion

Had to reread the title again since I thought I opened a different article about TLA+.

As for SQL, if you're referring to DBMS systems, here's what E.F. Codd, inventor of relational algebra, had to say about them and the departure from his work: https://thaumatorium.com/articles/the-papers-of-ef-the-coddf...

aledevvtoday at 8:13 AM

> If you are a junior developer, “learn SQL properly” is the most valuable 40 hours you can spend. Not a tutorial. Not an ORM. Actual SQL: joins, subqueries, window functions, query plans. That investment pays you back at every job, in every stack, for decades

This is the power of low-level reasoning.

Today, even for a junior developers, even if they have AI that solves syntax problems, SQL teaches you to reason and approach problems logically. Without any wrapper masking low-level logic.

It's something like the letters of the alphabet that form concepts: why should they change?

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teleforcelast Monday at 7:29 AM

>The Only Programming Language Built on Mathematics, Not Fashion

As a modern array language D4M is the natural successor for SQL [1].

D4M is based on mathematics like SQL, specifically associative array algebra but not relational unlike SQL. It's more generic since can it caters to most modern data abstractions including spreadsheets, database tables, matrices, and graphs [2].

You can achieve 100M database inserts per second with D4M and Accumulo more than a decade ago back in 2014 [3].

[1] D4M: Dynamic Distributed Dimensional Data Model:

https://d4m.mit.edu/

[2] Mathematics of Big Data: Spreadsheets, Databases, Matrices, and Graphs:

https://direct.mit.edu/books/monograph/5691/Mathematics-of-B...

[3] Achieving 100M database inserts per second using Apache Accumulo and D4M (2017 - 46 comments):

https://news.ycombinator.com/item?id=13465141

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ciconiatoday at 7:15 AM

I've been slowly transitioning from using an ORM to just plain SQL. It's so much simpler. Less magic, more explicitness, and more control. Also, much better performance. I think the thing is to construct your model around the different queries you need to perform. In many cases, especially a CRUD-type situation, you'll end up with 10-20 different SQL queries, and that's it.

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WAtoday at 6:22 AM

- I recently read that most programmers SQL knowledge is outdated by 20 years and it’s true for me. There are quite a lot of features in most DBs that feel very "new" to me.

- Comparing SQL to React weakens the argument. SQL is the language, React is a piece of software. You certainly can run 30 year old JS today in modern browsers.

alpertoday at 8:46 AM

One of the best things that happened to me is my boss giving me a crash course in advanced SQL at my first job. In the database we used at work, he gave me increasingly difficult questions to answer with queries.

It was a great foundation and has served me well to this day.

glimshetoday at 8:52 AM

Alternatives come and go, SQL stays.

It's not that I like or dislike SQL, it is just that it has such raw power and mature tooling/resources, I wonder what an alternative could even offer me.

It's like C. It does such a great job at being structured assembly that it is hard to displace it for similar reasons.

AnonHPtoday at 8:34 AM

I’ve always felt that SQL is somewhat easy to grasp for basic queries, but gets complex and difficult for even moderate to higher complexity use cases. My eyes glaze over when I read long stored procedures that someone else has written. Any recommended resources to go from beginner/beginner-intermediate to advanced?

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veqqtoday at 6:28 AM

> Edgar Codd formalised relational algebra in 1970. SQL sits on top of it as a declarative interface. You describe what you want. The database engine decides how to get it. The engine improves every year. Your query stays the same.

Although SQL is of course not relational Algebra (and others like Datalog and D4M are better), it's still cool. It inspired kSQL like Lil uses https://beyondloom.com/decker/lil.html#lilthequerylanguage , which inspired the code I'm most proud of: https://codeberg.org/veqq/declarative-dsls A common query language, a common idiom, for many data structures (arrays, hashmaps, datafremas) is liberating, permitting you to e.g. solve sudoku, make mandelbrot sets or calculate primes directly:

    (def n 40) # to reach primes up to, left is sqr of n, right n/2, then multiply them for rows
    (def composites
    (df/select :from (range 2 (+ 1 (math/floor (math/sqrt n))))
               :cross (range 2 (+ 1 (/ n 2)))
               :where |(<= (* ($ :value_left) ($ :value_right)) n)
               [[:value_left :value_right] :value
                |(* ($ :value_left) ($ :value_right))]))
    (df/select :from (range 2 (+ 1 n)) :exclude composites)
Or e.g.

    (import declarative-dsls/dataframes :as df)
    (def people (df/dataframe :name :age :job))
    (df/dataframe? people)
    
    (df/insert! {:name "Bob" :age 30 :job "Developer"} :into people)
    (df/insert! {:name "Alice" :age 27 :job "Sales"} :into people)
    (df/update! :set {:job "Engineer"}
             :where |(= ($ :job) "Developer")
             :from people)
    
    (df/save-csv people "people.csv" :sep "\\t")
    (def people2 (df/load-csv "people.csv" :sep "\\t"))
    
    (-> people2
       df/dataframe->rows
       df/rows->dataframe
       df/print-as-table)
The tests file has many such things (like the sudoku solver) and even datalog and minikanren implemented on top of this!
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meszmatetoday at 7:05 AM

I’ve been using Postgres for over 6 years (since I started), and I honestly think it’s one of the best investments you can make as a developer

pjmlptoday at 7:28 AM

Additionally learn stored procedures.

Helps simplify complex SQL queries and no need to waste network traffic on data that client side is never going to use, and waste CPU cycles processing it.

Yes, what about database portability?

I am on my 50s and it only mattered on a single project, which was anyway a middleware for application servers.

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vbezhenartoday at 7:57 AM

That's true. SQL knowledge is one of the few skills that didn't age.

1. C language.

2. *nix tools (shell and friends).

3. SQL.

4. Basic IPv4 networking.

These things I learned around 20 years ago, they didn't change much and they are useful for me to this day.

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drayfieldtoday at 7:27 AM

For me SQL has long been the gateway to the world of development. I work in the UK non-profit sector and traditionally this kind of technical knowledge is rare, so for any team I've worked with I've built learning pathways that start with SQL before pushing out into Python, Linux, and other things. We're not exactly at the bleeding edge of current technologies, but SQL has consistently proved to be a great jumping-off point for novices who have even a passing interest in computing.

mihaictoday at 7:19 AM

I've learned SQL around 20 years ago, and in all this time I've felt it was just a poorly designed language. It was always infuriating to write because of its verbose nature. Keywords were split into two words. I'm still shocked it's not "GROUPBY". There is no composition and modularization of logic, queries become massive expressions.

I know I'm in the minority in places like this, but I've spent all my life using ORMs, and never once regretted it. And I'm the kind of person that actually likes low-level C from time to time. SQL just feels like a poor abstraction layer: either go higher or lower.

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ivolimmentoday at 7:07 AM

Same can be said for learning an OO programming language or a procedural programming language. I learned C++ at school and started using Java on my first job. I forgot how to work correctly with pointers but I have tried multiple languages (using the same paradigms) and managed to build working software

grugdev42today at 8:22 AM

Agreed. SQL has been one of the most stable and useful skills I have.

Rivalled only by Linux, shell scripts, and Cron!

frollogastontoday at 6:54 AM

Everyone knows SQL already. The harder parts that pay off are schema design, knowing how to interact with your DB in code, and knowing all the ins and outs of whatever DBMS you're using.

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lanycrostlast Monday at 12:28 PM

I've played once with codesignal to pass SQL chapters and it really helped to advance querying skills.

einpoklumtoday at 8:43 AM

> SQL is the only programming language

SQL is not a programming language. You do not write programs in SQL. It's a declarative language (or set-of-sublanguages).

> a working developer can learn once and > use for 30 years without rewriting their mental model.

There is any number of long-living languages which satisfy this.

Plus, SQL it's not even really a single language, because the spec changes, and is huge, and few people know it fully; and the dialects have non-trivial differences; and if you switch DBMSes, you often switch SQL dialect. In that sense, it is very much like other programming languages which evolve, like C++ or Fortran or even C.

deepsuntoday at 6:58 AM

Just, for god's sake, move SELECT after GROUP BY, I beg you.

curtisblainetoday at 6:43 AM

> JavaScript is an imperative language that browser wars, framework trends, and open-source maintainer preferences reshaped every few years. It rewards you for keeping up. > Take a React component from 2015

Javascript is actually fully backwards-compatible, to not break the Web. Any javascript from 10 years ago works in the browser. This is good but also a bit of a burden, since the language can only expand but not shrink. React is a library, and like all libraries it has breaking versions. Not understanding the basic difference between the two kinda undermines the credibility of the article.

Also, in a similar way, core, ANSI SQL is largely backwards compatible, but all the SQL dialects linked to various DBMS implementation are generally incompatible. Obviously that's not mentioned in the article.

> Not a tutorial. Not an ORM. Actual SQL: joins, subqueries, window functions, query plans.

Not text written by a human. Not a style that an real writer would ever use. Actual AI slop: Short sentences. Incorrect facts. Not X, Y.

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NetOpWibbytoday at 6:49 AM

I refuse to learn SQL. I'm not a computer, I'll let them deal with that.

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