The role of foreign keys in SQL database

Category: Ruby :: Published at: 31.05.2023

5 rules, why we use Foreign Keys in our databases:


  1. Relationships establishment - we can create relations between tables, and even inner join relation within one table between two records
  2. Data Integrity - for example, you can create an order with client_id for client which does not exist in the database
  3. Data consistency and accuracy - when foreign key is defined, it restricts the values that can be inserted or updated in the referencing column
  4. Data querying - thanks to the foreign keys we can retrieve data from multiple tables faster and easier
  5. Data maintenance - it helps cascading updates and deletions, preventing locks mechanisms

MonkeyPatching in Ruby - simple example

Category: Ruby :: Published at: 25.05.2023

MonkeyPatching in Ruby is actually extremely easy to understand and use.

We can monkey patch any ruby class, and this is how to do it.

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Run one spec multiple times

Category: Ruby :: Published at: 22.05.2023

Simple code to run one spec multiple times:

for i in `seq 10`; do rspec spec; done

How to create simple Docker container with Python code?

Category: Machine Learning :: Published at: 04.03.2023

This is how i usually create a simple Docker container for Python code:

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How to download sql dump and import it into pg database on local env

Category: SQL :: Published at: 23.02.2023

This is the simple instruction on how to download the dump file with sql database and import it to the local postgreqsql database

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How to use basic Redis commands?

Category: Ruby :: Published at: 30.01.2023

Redis is quite easy to use, it's just basic key->value database which can be used in many different cases.

Let's assume, we already have Redis server setup in our application, and only need to use it.

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