feat: add junior-2 and junior-3 program

backend/node.js/README.md

@@ -1,7 +1,10 @@
 # Список уровней:
 
 - **Junior:**
-    * [junior-1](./junior-1/README.md)
+
+  - [junior-1](./junior-1/README.md)
+  - [junior-2](./junior-2/)
+  - [junior-3](./junior-3/README.md)
 
 - **Middle**
 

backend/node.js/junior-1/databases/PostgreSQL.md

@@ -1,28 +1,27 @@
 # PostgreSQL
 
-* What is PostreSQL?
-* What are the basic most commonly used types?
-* What are domains? How to create a domain? How to create custom type? Enum type?
-* What is constraint?
-* How to use this constraints?
-  * Primary Key
-  * Foreign Key
-  * Unique
-  * Not Null
-* How to use transactions in sql?
-* How to create dump?
-* How to restore dump?
-* What is a View table?
-  * How to create it?
-  * How to update it?
-  * What is materialized views?
-
+- What is PostgreSQL?
+- What are the basic most commonly used types?
+- What are domains? How to create a domain? How to create custom type? Enum type?
+- What is constraint?
+- How to use this constraints?
+  - Primary Key
+  - Foreign Key
+  - Unique
+  - Not Null
+- How to use transactions in sql?
+- How to create dump?
+- How to restore dump?
+- What is a View table?
+  - How to create it?
+  - How to update it?
+  - What is materialized views?
 
 ### Resources
 
-* [Postgresql documentation: Chapter 8. Data Types](https://www.postgresql.org/docs/current/datatype.html)
-* [A Look at PostgreSQL User-defined Data Types](https://neon.tech/postgresql/postgresql-tutorial/postgresql-user-defined-data-types)
-* [PostgreSQL enum](https://neon.tech/postgresql/postgresql-tutorial/postgresql-enum)
-* [Postgres Constraints for Newbies](https://www.crunchydata.com/blog/postgres-constraints-for-newbies)
-* [PostgreSQL Transaction](https://neon.tech/postgresql/postgresql-tutorial/postgresql-transaction)
-* [PostgreSQL Views](https://neon.tech/postgresql/postgresql-views)
+- [Postgresql documentation: Chapter 8. Data Types](https://www.postgresql.org/docs/current/datatype.html)
+- [A Look at PostgreSQL User-defined Data Types](https://neon.tech/postgresql/postgresql-tutorial/postgresql-user-defined-data-types)
+- [PostgreSQL enum](https://neon.tech/postgresql/postgresql-tutorial/postgresql-enum)
+- [Postgres Constraints for Newbies](https://www.crunchydata.com/blog/postgres-constraints-for-newbies)
+- [PostgreSQL Transaction](https://neon.tech/postgresql/postgresql-tutorial/postgresql-transaction)
+- [PostgreSQL Views](https://neon.tech/postgresql/postgresql-views)

backend/node.js/junior-2/README.md

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+# Node.js Junior 2 level
+
+- [Docker](../../shared/junior-2/docker.md)
+- [Linux](../../shared/junior-2/linux.md)
+- [SQL](./databases/sql.md)
+- [Integration Tests](./tests/intergation-tests.md)

backend/node.js/junior-2/databases/sql.md

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+# Junior-2 Sql level
+
+##### `The Postgresql DBMS dialect`
+
+- ###### `ORDER BY`
+
+- What is an `ORDER BY` and what is it used for?
+- What types of `ORDER BY` sorting exist?
+
+- ###### `LIMIT and OFFSET`
+
+- What is the `LIMIT`?
+- What is the `OFFSET`?
+- Give an example of how `LIMIT` and `OFFSET` can be used.
+
+### Tasks
+
+- Write an sql script that will pick up all users and sort them by id and creation time (descending sort), the script should pick up only 5 users. Table schema:
+
+```
+      user table
+ ________________________________
+| id | email | created_at | name |
+```
+
+### Resources
+
+- [Postgresql documentation: Order by](https://www.postgresql.org/docs/current/queries-order.html)
+- [Postgresql documentation: Take and limit](https://www.postgresql.org/docs/current/queries-limit.html)

backend/node.js/junior-2/tests/intergation-tests.md

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+# Basics and terminology:
+
+- What is integration testing and how does it differ from unit testing?
+- Which components are usually tested in an integration test?
+- What are the advantages and disadvantages of integration testing?
+- What tools do you know for conducting integration testing in Node.js ?
+- What is the complexity of integration testing compared to unit testing?
+
+### Recommendations
+
+- It is best to raise a separate database that is designed specifically for testing (for example, raise the database via docker)
+
+### Resources
+
+- [Jest documentation](https://jestjs.io/docs)
+- [Jest documentation: Getting started](https://jestjs.io/docs/getting-started)
+- [Integration testing](https://en.wikipedia.org/wiki/Integration_testing)
+- [Cypress](https://www.cypress.io)

backend/node.js/junior-3/README.md

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+# Node.js Junior 3 level
+
+- [Design Principles](../../../shared/junior-3/basicCodingAndDesignPrinciples.md)
+- [Git](../../../shared/junior-3/git.md)
+- [Testing](../../../shared/junior-3/testing.md)
+- [Typescript](./ts/ts.md)
+- [SQL](./databases/sql.md)
+- [NoSql](./databases/nosql.md)
+- [Patterns](./patterns/patterns.md)

backend/node.js/junior-3/databases/nosql.md

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+# Junior-3 level Not only Sql
+
+- `BASE`, what is it?
+- What kind of in-memory database do you know and what can it be used for?
+
+### Resources
+
+- [BASE](https://www.lifewire.com/abandoning-acid-in-favor-of-base-1019674)
+- [Redis documentation](https://master--redis-doc.netlify.app/docs/)
+- [Dev: Caching](https://dev.to/aseemwangoo/using-redis-for-caching-2022-2og5?ysclid=m55dcpi0cw300594505)

backend/node.js/junior-3/databases/sql.md

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+# Junior-3 level Sql
+
+##### `The Postgresql DBMS dialect`
+
+- ###### `aggregation functions`
+
+* What are `aggregation functions`?
+* What are the `aggregation functions` for?
+* What does each of these `aggregation functions` do? `COUNT`, `MIN`, `MAX`, `AVG`, `ARRAY_AGG`, `JSON_AGG`, `JSON_ARRAYAGG`, `SUM`, `XMLAGG`
+* What is the `GROUP BY`?
+* What is the `HAVING`?
+
+- ###### `JSON structure in database`
+
+* What is the `JSONB`?
+* Which data structure might `JSONB` be suitable for?
+
+- ###### `JOIN`
+
+* What is the `SELF JOIN`?
+
+- ###### `General`
+
+* `ACID`, what is it?
+
+### Resources
+
+- [Postgresql documentation: Aggregate functions](https://www.postgresql.org/docs/current/functions-aggregate.html)
+- [Dev: Aggregate functions](https://dev.to/timescale/how-postgresql-aggregation-works-and-how-it-inspired-our-hyperfunctions-design-33k6?ysclid=m55b6zmvxm400507156)
+- [Postgresql documentation: JSONB](https://www.postgresql.org/docs/current/datatype-json.html)
+- [ACID](https://en.wikipedia.org/wiki/ACID)
+- [Dev: ACID](https://dev.to/karimerrahli/acid-in-database-systems-11ih?ysclid=m55d6li2ol351610386)

backend/node.js/junior-3/patterns/patterns.md

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+# Junior-3 level Patterns
+
+- What is `MVC`?
+- What is `MVVM`?
+
+### Resources
+
+- [MVC pattern](https://doka-guide.vercel.app/tools/architecture-mvc/)
+- [MVVM pattern](https://dev.to/nhannguyendevjs/basic-mvvm-architecture-in-javascript-with-knockoutjs-14nk?ysclid=m57ynnexqh42409593)

backend/node.js/junior-3/ts/ts.md

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+# Typescript
+
+- What is metadata in typescript?
+- Where can I use metadata?
+- Which library would you use for metadata?
+- What is a property descriptor?
+- What types of decorators are there?
+- What is function overloading?
+- What properties do I need to include in tsconfig in order for the decorators to work?
+- What are alias paths for in typescript?
+
+### Task
+
+- Write a decorator that will collect dependency data in the constructor.
+- Write a decorator that, when a class method is instantiated, outputs a message with the class name to the console.
+
+### Resources
+
+- [Official documentation: decorators](https://www.typescriptlang.org/docs/handbook/decorators.html)
+- [Reflect metadata](https://techsparx.com/nodejs/typescript/decorators/reflection.html)
+- [Dev: functions overload](https://dev.to/logrocket/implementing-function-overloading-in-typescript-2o7j?ysclid=m55bql87gj305756575)