Differences Between MySQL and Postgres

 

MySQL and Postgres are two of the most popular SQL databases. They have some key differences in syntax and features which can make jumping between the two a bit tricky.

Here are 5 differences that can have impact in your queries, that I faced personally.

1. MySQL is case insensitive, Postgres is case sensitive

- 𝚜𝚎𝚕𝚎𝚌𝚝 𝙸𝙳, 𝙽𝙰𝙼𝙴 𝚏𝚛𝚘𝚖 𝚞𝚜𝚎𝚛𝚜 𝚠𝚑𝚎𝚛𝚎 𝚗𝚊𝚖𝚎 = '𝙹𝚘𝚑𝚗'

- 𝚜𝚎𝚕𝚎𝚌𝚝 𝚒𝚍, 𝚗𝚊𝚖𝚎 𝚏𝚛𝚘𝚖 𝚞𝚜𝚎𝚛𝚜 𝚠𝚑𝚎𝚛𝚎 𝚗𝚊𝚖𝚎 = '𝚓𝚘𝚑𝚗'

- In Postgres, searching for "john" vs "John" will yield different results, whereas in MySQL it will return the same result set

- Also, selecting "ID, NAME" will throw an error in Postgres if the columns are lowercase (which they should be for Postgres)

2. MySQL allows camelCase for identifiers, Postgres does not

- select dob as 𝚍𝚊𝚝𝚎𝙾𝚏𝙱𝚒𝚛𝚝𝚑 from users where id = 1

- This query will return the dataset with the 𝚍𝚊𝚝𝚎𝙾𝚏𝙱𝚒𝚛𝚝𝚑 column for MySQL, but 𝚍𝚊𝚝𝚎𝚘𝚏𝚋𝚒𝚛𝚝𝚑 for Postgres. Be careful when mapping raw query results to objects in code.

3. MySQL allows ON UPDATE to auto-update column values, but Postgres does not

- For columns like updated_at, in MySQL we can simply declare the table definition as “𝚌𝚘𝚕𝚞𝚖𝚗 𝚞𝚙𝚍𝚊𝚝𝚎𝚍_𝚊𝚝 𝚍𝚊𝚝𝚎𝚝𝚒𝚖𝚎 𝚘𝚗 𝚞𝚙𝚍𝚊𝚝𝚎 𝚌𝚞𝚛𝚛𝚎𝚗𝚝_𝚝𝚒𝚖𝚎𝚜𝚝𝚊𝚖𝚙”

- In postgres, you have to create a separate trigger on the table to achieve the same thing

4. MySQL allows the use of boolean column values interchangeably between 1/0 and TRUE/FALSE, while Postgres only uses TRUE/FALSE values.

- For columns like updated_at, in MySQL we can simply declare the table definition as “column updated_at datetime on update current_timestamp”

- In Postgres, you have to create a separate trigger on the table to achieve the same thing

    - select * from users where is_active = 1

    - let’s say is_active is a boolean column. this query will work in mysql but not in postgres

    

5. MySQL allows bulk-updating multiple rows for a partial set of columns, while for Postgres you must pass the whole row’s values

- In MySQL you can do something like this, where you can update columns for multiple records by the primary ID (or unique constraint), while keeping other columns intact.

  𝙸𝙽𝚂𝙴𝚁𝚃 𝙸𝙽𝚃𝙾 𝚝𝟷 (𝚒𝚍,𝚗𝚊𝚖𝚎) 𝚅𝙰𝙻𝚄𝙴𝚂 (𝟷,'𝙹𝚘𝚑𝚗'),(𝟸,'𝙹𝚊𝚗𝚎') 𝙰𝚂 𝚗𝚎𝚠

  𝙾𝙽 𝙳𝚄𝙿𝙻𝙸𝙲𝙰𝚃𝙴 𝙺𝙴𝚈 𝚄𝙿𝙳𝙰𝚃𝙴 𝚗𝚊𝚖𝚎 = 𝚗𝚎𝚠.𝚗𝚊𝚖𝚎;

- For Postgres there is a similar "𝙾𝙽 𝙲𝙾𝙽𝙵𝙻𝙸𝙲𝚃 (𝚒𝚍) 𝙳𝙾 𝚄𝙿𝙳𝙰𝚃𝙴” statement, but for that you cannot just have “id,name”, you will need to pass all the columns of the user table for the bulk-update to work.

1. MySQL is case insensitive, Postgres is not

2. MySQL allows camelCase identifiers, Postgres does not

3. MySQL allows "ON UPDATE" for columns, Postgres needs a trigger for the same

4. MySQL allows 1/0 and TRUE/FALSE for Boolean, while Postgres only allows 1/0

5. MySQL allows bulk-updating a partial set of columns for multiple records, Postgres does not

6. Postgres has no autoincrement. Mysql allows for an autoincrement on PRIMARY KEY.

MySQL also has a 'heartbeat' for easy replication/synchronization. Postgres does not.

Best Free Video Production Tools

Unleashing Your Creativity with OBS Studio: A Powerful Broadcasting Tool

Introduction:

In an era where content creation and live streaming have become increasingly popular, having the right tools to capture, produce, and share your creations is essential. Enter OBS Studio, a versatile and feature-rich software that has emerged as the go-to choice for both aspiring and professional content creators. This article explores the essence of OBS Studio, its key features, and why it has become an indispensable tool for individuals across various domains.

What is OBS Studio?

OBS Studio, short for Open Broadcaster Software Studio, is a free and open-source software for video recording and live streaming. Originally developed by Hugh "Jim" Bailey as a personal project, OBS Studio has evolved into a robust platform that supports Windows, macOS, and Linux, making it accessible to a wide range of users.

Key Features of OBS Studio:

Live Streaming: OBS Studio enables users to effortlessly broadcast their content across popular platforms such as Twitch, YouTube, Facebook Live, and more. With support for multiple stream profiles and customizable settings, it offers flexibility for various streaming requirements.

Scene Composition: The software's scene system allows users to create complex layouts by combining multiple sources such as captured windows, images, text, webcams, and more. Users can seamlessly switch between scenes during a live stream or recording, enhancing visual engagement for viewers.

Audio Mixing: OBS Studio facilitates precise audio control through a mixer, enabling users to manage multiple audio sources independently. This feature is particularly valuable for live streamers who often need to balance game audio, microphone input, music, and other sound effects.

Transition Effects: Smoothly transitioning between scenes is crucial for maintaining a polished production. OBS Studio offers a range of transition effects, including fade, swipe, stinger, and more. These transitions add a professional touch to content and improve viewer experience.

Video Recording: In addition to live streaming, OBS Studio allows users to record high-quality videos locally. It offers various encoding options, allowing users to choose the desired resolution, frame rate, and bitrate to suit their recording needs.

Plugin Support: OBS Studio's plugin architecture empowers users to extend the software's functionality and customize their workflows. A vibrant community of developers has contributed numerous plugins, expanding the software's capabilities even further.

Why Use OBS Studio?

Versatility: OBS Studio caters to a wide range of users, from gamers and podcasters to educators and professionals. Whether you're a content creator sharing gameplay footage, a teacher delivering online lectures, or a business conducting webinars, OBS Studio provides the tools you need.

Cost-effective: OBS Studio's open-source nature means it is entirely free to use, making it an attractive choice for individuals and organizations with budget constraints. Despite its cost-effectiveness, OBS Studio doesn't compromise on quality or functionality.

User-Friendly Interface: While OBS Studio boasts advanced features, its interface remains intuitive and user-friendly. The software provides a straightforward setup process and offers extensive documentation and community support to assist users of all skill levels.

High Performance: OBS Studio is known for its low system resource usage, ensuring smooth performance even during resource-intensive tasks. It leverages hardware acceleration, optimizing performance while minimizing strain on the CPU.

Official Website: https://obsproject.com/

KDenLive: Empowering Video Editing with Open-Source Excellence

Introduction:

When it comes to video editing, having a reliable and feature-rich software can make all the difference in creating captivating content. KDenLive, an open-source non-linear video editing software, has emerged as a powerful tool for both amateur and professional video editors. In this article, we will delve into the world of KDenLive, exploring its features, advantages, and why it has become a compelling alternative to proprietary software like Adobe Premiere Pro.

What is KDenLive?

KDenLive is a free and open-source video editing software, designed to provide a comprehensive solution for creating high-quality videos. Developed for Linux systems, it is also compatible with Windows and macOS, making it accessible to a wide range of users. KDenLive utilizes a non-linear editing approach, allowing editors to work with multiple video and audio tracks simultaneously.

Key Features of KDenLive:

Multitrack Editing: KDenLive enables users to work with an unlimited number of video and audio tracks, providing flexibility in creating complex compositions. This feature is particularly beneficial when dealing with multi-camera footage or incorporating multiple audio sources.

Advanced Effects and Transitions: With KDenLive, editors can apply a wide range of effects and transitions to enhance their videos creatively. From basic adjustments like color correction and cropping to advanced effects such as chroma keying and keyframing, KDenLive offers comprehensive tools to elevate the visual appeal of your content.

Timeline and Clip Management: The software provides an intuitive timeline interface, allowing precise control over the arrangement and duration of clips. Users can easily trim, split, and rearrange clips, simplifying the editing process and improving overall workflow efficiency.

Proxy Editing: To ensure smooth editing of high-resolution footage, KDenLive offers proxy editing. This feature generates lower-resolution proxy files for editing, reducing the strain on system resources. Editors can switch seamlessly between proxy and original files for faster editing while maintaining the quality during the final render.

Audio Mixing and Keyframing: KDenLive provides comprehensive audio editing capabilities, including volume adjustment, audio keyframing, and noise reduction. This allows editors to achieve a balanced audio mix, enhance dialogue clarity, and control audio levels throughout the video.

Why Use KDenLive?

Open-Source Freedom: KDenLive's open-source nature means it is free to download, use, and modify. This makes it an appealing choice for individuals and organizations with limited budgets. Additionally, the open-source community provides regular updates, bug fixes, and feature enhancements, ensuring a continuously evolving software.

Cross-Platform Compatibility: KDenLive's compatibility with Linux, Windows, and macOS enables users to seamlessly transition between different operating systems without compromising their projects. This flexibility allows video editors to work with their preferred system or adapt to different environments as needed.

User-Friendly Interface: Despite its robust capabilities, KDenLive boasts a user-friendly interface, making it accessible to both beginners and experienced editors. The software offers an intuitive layout, customizable workspace, and extensive documentation, providing a smooth learning curve for newcomers.

Integration with Other Tools: KDenLive integrates well with other open-source tools, expanding its functionality and allowing users to enhance their editing process. From audio tools like Audacity to graphic design software like GIMP, KDenLive seamlessly integrates with various applications, providing a comprehensive editing ecosystem.

KDenLive  VS Adobe Premiere Pro

While Adobe Premiere Pro is a widely-used proprietary software, KDenLive offers several advantages:

• Cost: KDenLive is free, making it a cost-effective choice, especially for those on a tight budget.
• Open-Source Customization: KDenLive's open-source nature allows users to modify and extend the software, tailoring it to their specific needs.
• Cross-Platform Compatibility: KDenLive supports multiple operating systems, enabling editors to work seamlessly across platforms without additional licensing costs.
• Community Support: KDenLive benefits from a passionate open-source community that actively contributes to its development and provides support through forums and online resources.

Official Website: https://kdenlive.org/en/download/

Audacity: The Sound of Creativity and Versatility

Introduction:

When it comes to audio editing and recording, having a reliable and feature-rich software can make all the difference in achieving professional-quality results. Audacity, an open-source audio editing software, has become a go-to choice for both beginners and experts in the field. In this article, we will explore the world of Audacity, its powerful features, and the reasons why it has gained widespread popularity among audio enthusiasts.

What is Audacity?

Audacity is a free and open-source digital audio workstation (DAW) that provides a comprehensive suite of tools for recording, editing, and mixing audio. Compatible with Windows, macOS, and Linux, Audacity offers a user-friendly interface that allows users to manipulate audio files with precision and flexibility.

Key Features of Audacity:

Recording and Editing: Audacity allows users to record audio directly or import existing audio files for editing. With its multi-track capability, users can work with multiple audio sources simultaneously, making it ideal for podcasts, music production, voiceovers, and more.

Editing Tools: Audacity provides a wide range of editing tools, enabling users to perform precise adjustments to their audio. These tools include cut, copy, paste, trim, and delete, allowing for seamless editing and arrangement of audio clips.

Effects and Plugins: Audacity offers a plethora of built-in audio effects and supports third-party plugins. Users can apply effects like equalization, noise reduction, compression, reverb, and more to enhance the quality and creativity of their audio projects.

Spectrogram View: The spectrogram view in Audacity provides a visual representation of audio frequencies over time. This feature is particularly useful for analyzing and editing audio recordings, identifying specific sound frequencies, and troubleshooting audio issues.

Batch Processing: Audacity's batch processing feature allows users to apply the same set of effects or editing actions to multiple audio files simultaneously. This saves time and effort, especially when working with large batches of audio files.

Export and Import Options: Audacity supports a wide range of audio file formats, including WAV, MP3, AIFF, FLAC, and more. It also allows users to export audio projects to various formats, making it easy to share and distribute their creations.

Why Use Audacity?

Free and Open Source: Audacity is free to download and use, making it an affordable option for audio enthusiasts, professionals, and those with limited budgets. Its open-source nature also encourages community contributions, resulting in regular updates, bug fixes, and improvements.

User-Friendly Interface: Despite its powerful capabilities, Audacity boasts a user-friendly interface that caters to both beginners and advanced users. The software offers a straightforward layout, intuitive controls, and comprehensive documentation, ensuring a smooth learning curve for all users.

Versatility and Flexibility: Audacity is a versatile tool that caters to a wide range of audio editing needs. Whether you're editing podcasts, creating music, cleaning up recordings, or conducting audio research, Audacity provides the tools necessary for professional-quality results.

Extensive Editing Tools: Audacity's comprehensive set of editing tools allows users to perform precise adjustments, corrections, and enhancements to their audio. From basic edits to advanced effects and processing, Audacity empowers users to achieve their desired audio outcomes.

Supportive Community: Audacity benefits from a dedicated community of users and developers who actively contribute to its development and provide support. Online forums, tutorials, and resources are readily available, ensuring assistance is always within reach.

Official Website: https://www.audacityteam.org/download/

Sololearn: Create a timer program that will take the number of seconds as input, output the remaining time and countdown to 0.

Create a timer program that will take the number of seconds as input, output the remaining time and countdown to 0.

Example:
Input: 3

Expected Output:
3
2
1
0

------------------------------

In Python3

# take the number as input number = int(input()) #use a while loop for the countdown while number >= 0: print(number) number -= 1

--------------------------

In JS

let num = parseInt(readLine(), 10); //your code goes here while (num > -1) { console.log(num); num--; }

--------------

In C++

#include <iostream> using namespace std; int main() { int seconds; cin >> seconds; while (0 <= seconds){ cout << seconds << endl; seconds--; } return 0; }

Visual Studio Code Theme to PyCharm, PhpStorm, WebStorm, Jetbrain Theme Convertion

Health OS - REPLIQ Junior Django Developers Quiz 2023

 

 Is the Django ORM slow?

Ans: Yes, it's at least slower than raw sql queries

 When should You use Model.objects.select_related(...)?

Ans: 

What is a template in Django?

Templates are usually text files that are placeholders for static and dynamic content

Templates are files that contain HTML

Templates are files that contain XML

All of the above

None of the above

 How would You extend/customize Django's User model with custom fields?

I would define a One-To-One field named "profile" and connect it to a model named Profile and then define my fields there

I would use the AbstractBaseUser class and then extend it with a CustomUser model

I would write my own class from scratch in order to customize logic

I would write a signal that connect the built in User model to a second model that will hold my custom fields

All of the above makes sense

None of the above makes sense

What does MVT stand for?

Model View Tag

Model Validation Tool

Model View Template

Model Verification Tag

You want to store a floating point number in a model. What built-in model field would You use to store it?

DecimalField

IntegerField

CharField

FloatField

All of the above

None of the above

What type of logic should You store in a model?

Database validation logic

Logic related to an instance/row in the database

Store column information and meta data

Primary keys and their relationships

Store index related configuration

All of the above

None of the above

Does Django handle migrations for You?

Yes

Only if You write some specific logic

No

What is a Django management script?

It is a way to run code outside of the request/response loop

It is a script that generates static HTML in a Django project

It is some arbitrary code that runs every hour to do some cleanup

All of the above

None of the above

When should one use serializers.SerializerMethodField(...)?

When I want to represent some data in a model in a different way than the way it is stored in the model

When I want to calculate a certain value not related to the model

When I want to ignore model data but return something useful

All of the above

None of the above

What is REST?

A protocol for storing data in the backend

A client that handles communication between the server and the database

A method to communicate between client and server

An HTTP layer that handles communication between two parties

All of the above

None of the above

What is the purpose of Abstract classes?

An abstract class is a class that uses the same table but You can specify customized behavior

An abstract class is a blueprint that other classes can use in order to inherit certain attrbutes and methods

An abstract class is a class which defines an interface so that other classes can expect a defined set of behaviours from it

When should You use Model.objects.select_related(...)? 

When I want to fetch known field data from related tables and not fetch the data lazily

When I want to load many rows at once and cache the queryset

When I want to load relational meta data before I traverse the data in Python

What is the purpose of Proxy models in Django?

Proxy models share the same table but You can customize its logic and behavior in Python

Proxy models work as interfaces that every instance inherits to share the same logic

You set proxy = True in the class Meta to use a Django proxy model

All of the above

None of the above

How would You write a Django REST Framework view that only allows for changing a single field in a model thru a REST call?

Create a serializer with one defined field and map it to a UpdateView view where url can be something like '/api/v1/fruits/<slug>/fieldname'

Use a ModelSerializer and expose one field and then make it accessible so that the developer can make a PATCH request

Define a raw function that takes the form data and manually validate it and then sets a specific field

I would use a ListView with a custom serializer that checks the request data and removes all other data except the data related to one field

I would define a Django ModelForm instance with one single exposed field

Is the Django ORM slow?

Yes

Yes, it's at least slower than raw sql queries

No

It depends

All of the above

None of the above

Not if You know what it does

What does a normal serializer do Django REST Framework?

It stores session data

It stores instance data

It has logic for converting between JSON data and Python objects

It handles conversion logic between XML and HTML

What is the purpose of MVC frameworks?

Clear separation of logic

More readable code

Better project structure

All of the above

None of the above

Is Django opinionated?

Yes!

It depends, what do You mean by opinionated?

No, frameworks do not have opinions

What database engine would You preferably use with Django?

MySQL

PostgreSQL

MongoDB

SQLite

Redis

ElasticSearch

Memcached

Celery

GraphQL

What does the root URL file do in Django?

It enlists all the REST endpoints

It is like an index of all the urls of a Django project

It holds all the urls in a certain module

What is Celery in the context of Django?

It is a vegetable that is used by the community as a mascot

It is cache invalidation service customized for Django

It is an asynchronous task queue that plays well with Django

All of the above

None of the above

Can You handle REST calls with Django out of the box?

Yes

No

Maybe

Can You store a Django model in an ElasticSearch index?

Yes, if You serialize the data and store it as XML

Yes, if You serialize the data and store it as JSON

Yes, only if You strip the HTML tags

Yes, as a string

No

What is the purpose of managers in Django?

Managers can handle logic related to many rows in the database

You can write custom methods to return filtered querysets

You can write methods for creating new instances

You can write methods to update many rows at once

All of the above

None of the above

How would You handle static files in Django?

I would upload them via an FTP call to a FTP server and then store the path in the database

I would store my files on AWS S3 or something similar and store the path in the database

I would store the whole file in my database as a BLOB

I would setup a static fileserver on my laptop and run Apache on it to serve the files

I would use a CDN service

All of the above

None of the above

How would You handle static files in Django?

I would upload them via an FTP call to a FTP server and then store the path in the database

I would store my files on AWS S3 or something similar and store the path in the database

I would store the whole file in my database as a BLOB

I would setup a static fileserver on my laptop and run Apache on it to serve the files

I would use a CDN service

All of the above

None of the above