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Taming the beast that is the Django ORM – An introduction

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Re: Taming the beast that is the Django ORM – An introduction

#61

Post by jampekka »

exceptione wrote: post #58
santiagobasulto wrote: post #41

I think Django's ORM is just AMAZING. And as with every other tool, it has to be used wisely. First, it let's you get started quickly and prototype. You can write unit tests, make sure everything is working as expected, then count queries and make sure you're being efficient with your SQL engine. Second, and even more importantly, it's crucial in the definition of the app and the Schema. Thinking in high level "class…

There is one part in me that says to not destroy your positive mood, there is another part in me that wishes to yell at the pythonistas in general to look outside the Python world. Too often I come across Python projects that are hyped and when I dive into it I find it rather underwhelming to say it politely. Invariably it turns out that those people don´t know any other language than Python. I see that as a general…

For pythonistas reading this: JVM and .NET frameworks are better for large projects in the sense that they turn even the simplest projects into large messes of pointless byzantine buggy architecture, which in some circles is a sign of "high quality".

Edit: That said, learning multiple programming languages (paradigms) is a very good idea. A reasonable dose of e.g. Java, .NET or C++ for example is great for understanding how programming languages and software should not be written. Learning modern JavaScript makes it obvious how Python really suffers from weak functional programming support, very bad performance and a horrible packaging system.

Re: Taming the beast that is the Django ORM – An introduction

#62

Post by greenchair »

juahan wrote: post #60
exceptione wrote: post #58

Earlier quoted context omitted.

There is one part in me that says to not destroy your positive mood, there is another part in me that wishes to yell at the pythonistas in general to look outside the Python world. Too often I come across Python projects that are hyped and when I dive into it I find it rather underwhelming to say it politely. Invariably it turns out that those people don´t know any other language than Python. I see that as a general…

How are those better?

job security for one big one

Re: Taming the beast that is the Django ORM – An introduction

#63

Post by eru »

exceptione wrote: post #58
santiagobasulto wrote: post #41

I think Django's ORM is just AMAZING. And as with every other tool, it has to be used wisely. First, it let's you get started quickly and prototype. You can write unit tests, make sure everything is working as expected, then count queries and make sure you're being efficient with your SQL engine. Second, and even more importantly, it's crucial in the definition of the app and the Schema. Thinking in high level "class…

There is one part in me that says to not destroy your positive mood, there is another part in me that wishes to yell at the pythonistas in general to look outside the Python world. Too often I come across Python projects that are hyped and when I dive into it I find it rather underwhelming to say it politely. Invariably it turns out that those people don´t know any other language than Python. I see that as a general…

ORMs are a bad idea in the first place: relations are a great way to organise your data, why would you want to sully that by converting to something object oriented?

> Too often I come across Python projects that are hyped and when I dive into it I find it rather underwhelming to say it politely. Invariably it turns out that those people don´t know any other language than Python.

To give a nice counterexample: Python's hypothesis library is really great, and compares favourably to its Haskell inspiration of QuickCheck.

Re: Taming the beast that is the Django ORM – An introduction

#64

Post by eru »

ebcode wrote: post #40

Anytime I hear ORM, I always think of this: https://blog.codinghorror.com/object-relational-mapping-is-t...

Yes. Object orientation is the problem here. Relations are (mostly) great to model business logic with. The article you linked mentions this:

> This eliminates the problem quite neatly, because if there are no objects, there is no impedance mismatch.

But:

> Integration of relational concepts into the languages. Developers simply accept that this is a problem that should be solved by the language, not by a library or framework.

> Over the last several years, however, interest in "scripting" languages with far stronger set and list support, like Ruby, has sparked the idea that perhaps another solution is appropriate: bring relational concepts (which, at heart, are set-based) into mainstream programming languages, making it easier to bridge the gap between "sets" and "objects".

I agree that bringing relations into your language is a good thing, but many languages are strong enough to do that as libraries, there's no need for baking support into your language. Just as hash-tables can be implemented as a library in most languages.

We have relations as a library in a Haskell dialect I was working with in a previous job. Worked like a charm, and no language support was needed. Python would also be flexible enough to use relations as a user-defined datatype. And so would many other languages.

Re: Taming the beast that is the Django ORM – An introduction

#65

Post by jampekka »

eru wrote: post #63
exceptione wrote: post #58

Earlier quoted context omitted.

There is one part in me that says to not destroy your positive mood, there is another part in me that wishes to yell at the pythonistas in general to look outside the Python world. Too often I come across Python projects that are hyped and when I dive into it I find it rather underwhelming to say it politely. Invariably it turns out that those people don´t know any other language than Python. I see that as a general…

ORMs are a bad idea in the first place: relations are a great way to organise your data, why would you want to sully that by converting to something object oriented? > Too often I come across Python projects that are hyped and when I dive into it I find it rather underwhelming to say it politely. Invariably it turns out that those people don´t know any other language than Python. To give a nice counterexample: Python…

> ORMs are a bad idea in the first place: relations are a great way to organise your data, why would you want to sully that by converting to something object oriented?

One big why is SQL. It's a horrible language/API but sadly practically all relational databases are SQL.

Re: Taming the beast that is the Django ORM – An introduction

#66

Post by LtWorf »

roze_sha wrote: post #16
wg0 wrote: post #13

Earlier quoted context omitted.

Nope. Python type hinting is far far from Java like types. And yes, I guess OP has now a large system that needs types enforced by the system to reduce the friction in evolving the stack.

What about using pydantic?

pydantic + sql database?

So have 2 components that ensure the types are correct? Why?

Re: Taming the beast that is the Django ORM – An introduction

#67

Post by agumonkey »

andybak wrote: post #51
bruce343434 wrote: post #48

Earlier quoted context omitted.

We've had serious trouble with migration merges when two people work on different parts of the code, yet in the same module, and they both generate a "migration nr. 6" on their feature branches.

Not at my desk but from memory, this is a something with a clearly documented "solution". I put that word in quotes because I don't want to imply it's a problem - it's just something you need to know how to handle.

Something in the official docs or more like shared through blogs or stackoverflow ?

Re: Taming the beast that is the Django ORM – An introduction

#68

Post by itsoktocry »

exceptione wrote: post #58
santiagobasulto wrote: post #41

I think Django's ORM is just AMAZING. And as with every other tool, it has to be used wisely. First, it let's you get started quickly and prototype. You can write unit tests, make sure everything is working as expected, then count queries and make sure you're being efficient with your SQL engine. Second, and even more importantly, it's crucial in the definition of the app and the Schema. Thinking in high level "class…

There is one part in me that says to not destroy your positive mood, there is another part in me that wishes to yell at the pythonistas in general to look outside the Python world. Too often I come across Python projects that are hyped and when I dive into it I find it rather underwhelming to say it politely. Invariably it turns out that those people don´t know any other language than Python. I see that as a general…

Wow, I didn't think people still thought like this in 2024.

The widespread use of Python is a problem? People should learn java? Okay.

I'll note you don't talk about the usefulness of the projects themselves, only your opinion of what the code "looks like".

Re: Taming the beast that is the Django ORM – An introduction

#69

Post by DarkNova6 »

santiagobasulto wrote: post #41

I think Django's ORM is just AMAZING. And as with every other tool, it has to be used wisely. First, it let's you get started quickly and prototype. You can write unit tests, make sure everything is working as expected, then count queries and make sure you're being efficient with your SQL engine. Second, and even more importantly, it's crucial in the definition of the app and the Schema. Thinking in high level "class…

May I ask, what experience do you have with other ORMs?

Re: Taming the beast that is the Django ORM – An introduction

#70

Post by 9dev »

ninetyninenine wrote: post #50

orms are exercises in OCD. Databases are the bottleneck your classic website. We choose to query these databases in a extremely high level language called SQL. This language is so high level that you need to come up with tricks and query analyzers in order to hack the high level query into something performant. A better abstraction would be one that's a bit more similar to a standard programming language with an std…

You are correct in your entire assessment, yet, you seem to underestimate the number of boring CRUD applications serviced by mediocre programmers. Limiting the number of technologies required to have at least a little knowledge in is a benefit, even if it hampers performance, because performance doesn’t matter for the vast majority of cases. Software engineers tend to overvalue that bit; the users of line-of-business apps don’t have a say anyway, but what matters is quick adaptability to changes in business logic.

So having an ORM in place that is tightly integrated in Python and Django lets even the junior developer fresh from the bootcamp make changes to an existing application.

It’s not a pretty story, but in my opinion the reason for staggering layers of complexity is the ability to move quickly even without experts on the team.

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