Node.js does have Node.js
worker_threads however.Some usage examples under: Section "Sequelize example".
As of 2021, this library is extremely painful to use. It does feel semi-mature, but there are just too much horrible things going on;
- the documentation is a bit messy and misses a lot of stuff. The examples are often too short, and it is hard to understand what specific options they are talking about do because they lack clear input/expected output pairs. Examples:
- the implementation has several inelegant/unintuitive annoyances/requirements of code repetition that drive you mad.The association API feels notably bad, it took a few days for Ciro Santilli to learn to do what he considers "basic" association operations, knowledge which he dumped to: stackoverflow.com/questions/22958683/how-to-implement-many-to-many-association-in-sequelize/67973948#67973948See also: how to decide if an ORM is good?.
- bugs are piling up. It appears that many key devs left, and current maintainers are just not being able to keep up.
Some glaring issues are listed at the horrors of Sequelize.
Two-dimensional Yang–Mills theory is a gauge theory that generalizes the concept of Yang–Mills theories to two spatial dimensions. In general, Yang–Mills theories are constructed from a gauge field that transforms under a symmetry group (the gauge group), and they play a crucial role in modern theoretical physics, particularly in quantum field theory and the Standard Model of particle physics.
To run examples on a specific database:All examples can be tested on all databases with:
./index.jsor./index.js l: SQLite./index.js p: PostgreSQL. You must manually create a database calledtmpand ensure that peer authentication works for it
cd sequelize
./testOverview of the examples:
- nodejs/sequelize/index.js: a bunch of basic examples
- nodejs/sequelize/update.js: This file is also where we are storing our expression-foo for now, e.g. how to do stuff like
col1 + col2. Such knowledge can however be used basically anywhere else however, e.g. inASorWHEREclauses, not just inUPDATE. - nodejs/sequelize/count.js: a simplified single-table count example. In practice, this will be usually done together with JOIN queries across multiple tables. Answers: stackoverflow.com/questions/22627258/how-does-group-by-works-in-sequelize/69896449#69896449
- nodejs/sequelize/date.js: automatic date typecasts
- nodejs/sequelize/like.js: LIKE
- nodejs/sequelize/camel_case.js: trying to get everything in the database camel cased, columns starting with lowercase, and tables starting with uppercase. The defaults documented on getting started documentation do uppercase foreign keys, and lowercase non-foreign keys. It's a mess.
- nodejs/sequelize/ignore_duplicates.js: ignore query on unique violation with
ignoreDuplicates: truewhich does SQLiteINSERT OR IGNORE INTOor PostgreSQLON CONFLICT DO NOTHING. Closely related Upsert versions:- Upsert
- nodejs/sequelize/upsert.js:
.upsertselects the conflict column automatically by unique columns. Both SQLite and PostgreSQL doINSERT INTO ON CONFLICT. PostgreSQL usesRETURNING, which was added too recently to SQLite: www.sqlite.org/lang_returning.html - nodejs/sequelize/update_on_duplicate.js:
.bulkCreate({}, { updateOnDuplicate: ['col1', col2'] }. Produces queries analogous to.upsert. This method is cool because it can upsert multiple columns at once. But it is annoying that you have to specify all fields to be updated one by one manually. - stackoverflow.com/questions/29063232/how-to-get-the-id-of-an-inserted-or-updated-record-in-sequelize-upsert/72092277#72092277
- stackoverflow.com/questions/55531860/sequelize-bulkcreate-updateonduplicate-for-postgresql
- Upsert
- nodejs/sequelize/inc.js: demonstrate the
incrementmethod. In SQLite, it produces a statement of type:UPDATE `IntegerNames` SET `value`=`value`+ 1,`updatedAt`='2021-11-03 10:23:45.409 +00:00' WHERE `id` = 3 - nodejs/sequelize/sync_alter.js: illustrates
Model.sync({alter: true})to modify a table definition, answers: stackoverflow.com/questions/54898994/bulkupdate-in-sequelize-orm/69044138#69044138 - nodejs/sequelize/truncate_key.js
- nodejs/sequelize/validation.js: is handled by a third-party library: github.com/validatorjs/validator.js. They then add a few extra validators on top of that.The
args: truething is explained at: stackoverflow.com/questions/58522387/unhandled-rejection-sequelizevalidationerror-validation-error-cannot-create-pr/70263032#70263032 - nodejs/sequelize/composite_index.js: stackoverflow.com/questions/34664853/sequelize-composite-unique-constraint
- nodejs/sequelize/indent_log.js: stackoverflow.com/questions/34664853/sequelize-composite-unique-constraint
- association examples:
- nodejs/sequelize/one_to_many.js: basic one-to-many examples.
- nodejs/sequelize/many_to_many.js: basic many-to-many examples, each user can like multiple posts. Answers: stackoverflow.com/questions/22958683/how-to-implement-many-to-many-association-in-sequelize/67973948#67973948
- ORDER BY include:
- nodejs/sequelize/many_to_many_custom_table.js: many-to-many example, but where we craft our own table which can hold extra data. In our case, users can like posts, but likes have a integer weight associated with them. Related threads:
- nodejs/sequelize/many_to_many_same_model.js: association between a model and itself: users can follow other users. Related:
- nodejs/sequelize/many_to_many_same_model_super.js
- nodejs/sequelize/many_to_many_super.js: "Super many to many": sequelize.org/master/manual/advanced-many-to-many.html This should not exist and shows how bad this library is for associations, you need all that boilerplate in order to expose certain relationships that aren't otherwise exposed by a direct
hasManywith implicit join table.
- nested includes to produce queries with multiple JOIN:
- nodejs/sequelize/nested_include.js: find all posts by users that a given user follows. Answers: stackoverflow.com/questions/42632943/sequelize-multiple-where-clause/68018083#68018083
- nodejs/sequelize/nested_include_super.js: like nodejs/sequelize/nested_include.js but with a super many to many. We should move this to nodejs/sequelize/many_to_many_super.js.
- two relationships between two specific tables: we need to use
as:to disambiguate them- nodejs/sequelize/many_to_many_double.js: users can both follow and like posts
- nodejs/sequelize/one_to_many_double.js: posts have the author and a mandatory reviewer
- hooks
- internals:
- nodejs/sequelize/common.js: common utilities used across examples, most notably:
- to easily setup different DBRM
- nodejs/sequelize/min_nocommon.js: to copy paste to Stack Overflow
- nodejs/sequelize/min.js: template for new exapmles in the folder
- nodejs/sequelize/common.js: common utilities used across examples, most notably:
The list of nuclear incidents in Japan includes various accidents, leaks, and problems related to nuclear power plants, research facilities, and other nuclear-related activities. Here are some significant incidents: 1. **Tokaimura Nuclear Accident (1999)**: A criticality accident occurred at a uranium processing facility in Tokaimura, Ibaraki Prefecture, resulting in two deaths and several others exposed to radiation. It was the first serious nuclear accident in Japan since the start of the nuclear power program.
The Jupiter trojans are a group of asteroids that share Jupiter's orbit around the Sun, located at the L4 and L5 Lagrange points, which are approximately 60 degrees ahead of and behind Jupiter in its orbit. The ones denoted as part of the "Greek camp" typically refer to those that are positioned at the L4 point.
The Jupiter trojans are a group of asteroids that share Jupiter's orbit around the Sun, clustering around the two stable Lagrange points (L4 and L5) which are 60 degrees ahead and behind Jupiter in its orbit, respectively. The List of Jupiter Trojans (Trojan camp) from 300001 to 400000 includes numerous numbered asteroids in that range.
The list of minor planets from 135001 to 136000 includes various asteroids that have been assigned numerical designations. This is part of the systematic cataloging of small celestial bodies within our solar system, primarily focusing on those that have been discovered and confirmed. Each minor planet is typically named after a person, place, or concept related to science, culture, or history.
The list of minor planets numbered 168001 to 169000 includes a range of asteroids and other small celestial bodies that have been assigned numbers by the Minor Planet Center. Each of these minor planets has its own unique characteristics, orbits, and sometimes names. The list typically includes details such as their designation numbers, discovery dates, and names (if applicable).
The list of minor planets numbered between 202001 and 203000 includes a wide range of asteroids and other small celestial bodies that have been assigned a number by the Minor Planet Center. These minor planets can vary in size, composition, and orbit characteristics, and they come from various regions of the solar system, including the asteroid belt and beyond.
The "List of minor planets: 205001–206000" refers to the cataloging of minor planets (also known as asteroids) that have been assigned numeric designations between 205001 and 206000. These minor planets are typically designated with a number upon discovery, and many may have additional names or designations based on mythological, historical, or other significant figures or events.
The list of minor planets from 218001 to 219000 includes various small celestial bodies that orbit the Sun. Minor planets, often referred to as asteroids, include a wide range of objects, including those found in the asteroid belt, trans-Neptunian objects, and centaurs. Each minor planet is designated with a unique number, and many also have names.
The list of minor planets designated with numbers from 228001 to 229000 includes various small celestial bodies, primarily asteroids, that have been cataloged by the Minor Planet Center. Each minor planet is assigned a unique number upon discovery. You can find detailed information about each of these minor planets, including their orbits, size, and discovery circumstances, on platforms like the JPL Small-Body Database or the Minor Planet Center's website.
Isomorphism theorems are fundamental results in abstract algebra that relate the structure of groups, rings, or other algebraic objects via homomorphisms. These theorems provide insight into how substructures correspond to quotient structures and how these correspondences reveal important properties of the algebraic system. The most well-known isomorphism theorems apply to groups, but similar ideas can be extended to rings and modules.
Pinned article: Introduction to the OurBigBook Project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 3. Visual Studio Code extension installation.Figure 4. Visual Studio Code extension tree navigation.Figure 5. Web editor. You can also edit articles on the Web editor without installing anything locally.Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.Video 4. OurBigBook Visual Studio Code extension editing and navigation demo. Source. - Infinitely deep tables of contents:
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact





