3 ms·

Incorrect: you need to know the "how" to create more complex and optimal queries. Your example is like saying, in Python, you just need to write print("Hello Wo

by wslh 2y ago

Incorrect: you need to know the "how" to create more complex and optimal queries. Your example is like saying, in Python, you just need to write print("Hello World!") to print something.

moomin 2y ago
That’s every programming language abstraction. All of them break when you get a fair amount of complexity or performance requirements.
- wslh 2y ago
  Imagine this concrete example: you are the best developer in the world in some specific area(s), except for UX/UI. If you wanted to create a relatively simple yet secure site with user authentication, even if described declaratively as “create a secure site with user authentication,” it would still take a significant amount of time to learn technologies like React and put everything in place. There are zillions of development teams doing the same work around the world.
lkuty 2y ago
I wouldn't say that since SQL was an improvement over previous ways to query data which were more concrete, like writing C code to get what you need. As such we are on a level of abstraction higher. Thus SQL specifies the "what", not the "how", with respect to those previous methods. However in complex queries, since we are constrained by the relational model (PK/FK), we may have a feeling of having to specify too much details.
SoftTalker 2y ago
That's why I said "somewhat." You aren't telling the database how to get those results from the files on the disk. You are telling it what values you want, matching what conditions, and (in the case of joins) what related data you want. If you want an aggregation grouped by some criteria you say what values you want summed (or averaged, etc.) and what the grouping criteria are, but not how to do it. Not a perfect example and it breaks entirely if you get into stuff like looping over a cursor but it is why SQL is usually called a declarative language.

by wslh 2y ago

Incorrect: you need to know the "how" to create more complex and optimal queries. Your example is like saying, in Python, you just need to write print("Hello World!") to print something.

moomin 2y ago

That’s every programming language abstraction. All of them break when you get a fair amount of complexity or performance requirements.

wslh 2y ago
Imagine this concrete example: you are the best developer in the world in some specific area(s), except for UX/UI. If you wanted to create a relatively simple yet secure site with user authentication, even if described declaratively as “create a secure site with user authentication,” it would still take a significant amount of time to learn technologies like React and put everything in place. There are zillions of development teams doing the same work around the world.

lkuty 2y ago

I wouldn't say that since SQL was an improvement over previous ways to query data which were more concrete, like writing C code to get what you need. As such we are on a level of abstraction higher. Thus SQL specifies the "what", not the "how", with respect to those previous methods. However in complex queries, since we are constrained by the relational model (PK/FK), we may have a feeling of having to specify too much details.

SoftTalker 2y ago

That's why I said "somewhat." You aren't telling the database how to get those results from the files on the disk. You are telling it what values you want, matching what conditions, and (in the case of joins) what related data you want. If you want an aggregation grouped by some criteria you say what values you want summed (or averaged, etc.) and what the grouping criteria are, but not how to do it. Not a perfect example and it breaks entirely if you get into stuff like looping over a cursor but it is why SQL is usually called a declarative language.