BC WEBDEV
Saved by @meera_w13

75+ SQL Interview Questions

⇩

 Level: Beginner to Medium
Topics:

➊ Introduction to RDBMS
➋ Normalisation
➌ Introduction to SQL
➍ Tables and Fields
➎ Constraints
➏ DDL
➐ DML & DQL
➑ Joins
➊ Introduction to RDBMS

➀ What is a Database?
➁ What are different types of Databases?
➂ What is DBMS?
➃ What is difference between Database and DBMS?
➄ What is RDBMS?
➅ Which are popular RDBMS vendors?
➆ What is ACID property in Database?
➋ Normalisation

➀ What is Normalisation?
➁ Why is Normalisation necessary?
➂ What are the disadvantages of not performing Normalisation?
➃ What are different Normal Forms (NF)?
➄ What is Denormalisation?
➌ Introduction to SQL

➀ What is SQL?
➁ What is the use of SQL?
➂ Is SQL a programming language?
➃ What are the different parts of SQL?
Or,
➄ Group SQL commands in different parts.
➅ What is DDL?
➆ What is DML?
➇ What is DQL?
➈ What is DCL?
➉ What is TCL?
➍ Tables and Fields

➀ What is a Table?
➁ What is a field in a Table?
➂ Write a SQL command to create a Table.
➃ How to change the name of a Table?
➄ How to truncate a table?
➅ How to drop a table?
➎ Constraints

➀ What is a constraint?
➁ What are different levels of constraints?
➂ Give examples of various constraints?
➃ What is a primary key?
➄ What is a unique key?
➅ Difference between a primary key and a unique key.
➆ What is a foreign key?
➇ What is NULL value?
➈ What is NOT NULL constraint?
➉ Is blank space or Zero (0) same as NULL?
➏ DDL

➀ Give some examples of DDL commands
➁ Write the syntax of creating a table
➂ How to specify the default value for a column?
➃ How to specify a foreign key?
➄ How to specify a unique key?
➅ How to specify multiple columns as the primary key?
➆ What are different constraints you can add to a column while creating a table?
➇ How to create a copy of a table? (both structure and, data)
➈ You have 'n' tables and asked to create a separate table which will contain a few columns from these tables with data being copied.
➉ What is SELECT INTO used for? (In SQL Server)
➀➀ Difference between ALTER and RENAME
➀➁ Can a previously nullable column be altered to a NOT NULL column? If yes, explain the steps.
➐ DML & DQL

➀ How to insert rows into a table?
➁ What are different syntaxes for inserting records into a table?
➂ What is the syntax to insert multiple records at a time?
➃ How to update data in a table?
➄ How to delete a row in a table?
➅ Difference between DELETE and TRUNCATE?
➆ Explain how DML operations are performed on a View.
Or,
➇ Are Views used only for SELECT queries?
➈ How to fetch rows of a table?
➉ What is a query condition? How to write it in SQL?
➀➀ How to sort the fetched records?
➀➁ What is grouping? How to write in SQL?
➀➂ How to find how many records are being fetched?
➀➃ How to find the maximum and minimum value for a field in fetched records?
➀➄ How to sum values in a field for all records?
➑ Joins

➀ What is a join in SQL?
➁ What are the different types of joins?
➂ What is Inner Join?
➃ What is Left Outer Join?
➄ What is Right Outer Join?
➅ What is Full Outer Join?
➆ What is Cross Join?
➇ What is a Self Join?
➈ What is Equi Join?
➉ What is Natural Join?

➀➀ Given a query in Cross Join, convert it into an Inner Join.

➀➁ Given a query in Right Outer Join, convert it into a Left Outer Join.
➀➂ Convert an Inner Join into an Equi Join.
Or,
➀➃ What is required to convert an Inner Join into an Equi Join?

➀➄ What should be taken care of to improve the performance of queries containing Joins.
🚥 Disclaimer

⬘ The questions covered here are mostly conceptual

⬗ I never claim only these types of questions are/should be asked during interviews

⬙ For interviews, you should have fundamentals strong. And you should be able to provide solutions to practical problems.
Hey 👋

I am a Tech Educator and, Mentor from India 🇮🇳

I am sharing Tutorials, Tips, Techniques, Infographics, Cheat Sheets, Practice Questions, Project Ideas and Roadmaps on Web Development, DSA and, Databases.

To never miss anything, Follow Me ✅

More from Swapna Kumar Panda

Swapna Kumar Panda
Swapna Kumar Panda
@swapnakpanda
JavaScript First, Then React?
Or,
JavaScript ✛ React?

⇩

👩‍💻 Beginning Words

There are 3 approaches one can take to start React journey

➊ Complete JavaScript. Then, start React.

➋ Learn the essentials of JavaScript. Then, start React. Finally, learn advanced JavaScript.

➌ Start React. Learn JavaScript alongside.

💭 Why is this Thread?

⬘ JavaScript is a language while React is one JavaScript-based library.

⬗ Looking at the popularity of React, few people directly start learning React without much/prior knowledge of JavaScript. Is this a good idea?

⬙ Whichever approach you may take, it's important to know what JavaScript concepts will make your React journey effective and, smoother.

⬖ We will discuss those essential concepts in this thread.

📋 JavaScript Essentials for React

➊ Basics
➋ String Methods
➌ Array Methods
➍ Array Destructuring
➎ Array Spread
➏ Object Destructuring
➐ Object Spread
➑ Template Literals
➒ ES Modules
➓ APIs & Others
ALL
Swapna Kumar Panda
Swapna Kumar Panda
@swapnakpanda
30+ resources to learn

❍ SQL
❍ PL/SQL
❍ NoSQL

⇩

➊.➀ freeCodeCamp

@mike_dane via @freeCodeCamp

➤ SQL Tutorial for

➊.➁ Web Dev Simplified (WDS)

@DevSimplified

➤ Learn SQL in 60

➊.➂ Programming with Mosh

@moshhamedani

➤ MySQL Tutorial for

➊.➃ Kevin Stratvert

@kevstrat

➤ SQL Tutorial for
SQL
Advertisement
Swapna Kumar Panda
Swapna Kumar Panda
@swapnakpanda
🌆 60+ CSS Shorthand Properties: Cheat Sheet


💎 Direct Link for High-Resolution Image

If you liked this one, give a ⭐️ to this GitHub repo to support my work.

✧ Direct

What did we cover?

Here are those.

➀ all
➁ background
➂ background-position
➃ font
➄ text-align
➅ text-decoration
➆ text-emphasis
➇ list-style
➈ offset
➉ overflow

➀➀ inset
➀➁ inset-block
➀➂ inset-inline
➀➃ margin
➀➄ margin-block
➀➅ margin-inline
➀➆ padding
➀➇ padding-block
➀➈ padding-inline
20. overscroll-behavior
➁➀ scroll-margin
➁➁ scroll-padding

➁➂ border
➁➃ border-top
➁➄ border-right
➁➅ border-bottom
➁➆ border-left
➁➇ border-block
➁➈ border-block-start
30. border-block-end
➂➀ border-inline
➂➁ border-inline-start
➂➂ border-inline-end
CATAGORY JEE
Swapna Kumar Panda \uea00
Swapna Kumar Panda ...
@swapnakpanda
🛣 Beginner's Roadmap for Front-End

HTML & CSS → 👩‍💻 → JavaScript → 👩‍💻
↓
👩‍💻 ← React* ← 👩‍💻 ← Tailwind*
↓
TypeScript → 👩‍💻 → Next.js* → 👩‍💻 → 🏁

⇩

What would we cover?

➊ HTML & CSS
➋ JavaScript
➌ CSS Frameworks
➍ UI Frameworks
➎ TypeScript
➏ Server-side Frameworks
➐ Practice, Practice and, Practice
➑ Other Skills
➒ Frequently Asked Questions

➊ HTML & CSS

⬘ Your Front-End journey shall always start from HTML & CSS and, ends with these as well.

⬗ Don't over burden yourself to learn everything at once. It's a continuous subject.

⬙ Do not separate HTML from CSS. That's


➋ JavaScript

JavaScript is essential. You should start with basics and move to complex subjects.

❍ JavaScript Syntaxes
(preferably ES6 onwards)
❍ HTML DOM API
❍ Event Handling
❍ Fetch


➌ CSS Frameworks

CSS Framework is necessary if you are planning to be a professional developer.

There are so many options available.

❍ Tailwind CSS
❍ Bootstrap
❍ Chakra
❍ Bulma
❍ Foundation
❍ Skeleton
❍ Pure CSS

Start with anything. You can switch any time.
FRONTEND
Swapna Kumar Panda
Swapna Kumar Panda
@swapnakpanda
👩‍💻 75+ SQL Practice Questions

❍ Oracle
❍ MySQL
❍ SQL Server
❍ PostgreSQL
❍ SQLite

⇩

Topics covered:

➊ Table
➋ Constraints
➀ Primary Key
➁ Unique
➂ Not Null
➃ Default
➄ Check
➅ Foreign Key
➌ Insert, Update, Delete
➍ Select

➊ Table

➀ Create a Table with a few fields by specifying their data types.

➁ Add a field to an existing table.

➂ Modify a field's data type of a table.

➃ Rename a field's name.

➄ Remove a field from a table.

➅ Rename a table's name.

➆ Drop a table.

➋ Constraints

➀ Primary Key
➁ Unique
➂ Not Null
➃ Default
➄ Check
➅ Foreign Key

➋.➀ Primary Key

➤ Create a Table with
➀ a single field as the primary key
➁ 2 or, more fields as the primary key
...

➤ Add a primary key to an existing table
➂ for a single field
➃ for 2 or, more fields
...
SQLBASICS

More from Webdev

Pratham
Pratham
@Prathkum
Five great icons websites for every web developer and designer ⏺️

A Thread 🧵👇🏻


1️⃣ Icons 8

- Icons8 is just more than icons. You can download illustrations, vector images, music and much more

🖇️ https://t.co/inHse0QXBh


2️⃣ Icon Monstr

- Black and white themed minimal icons which looks super great. You can also cuatomize the thickness

🖇️ https://t.co/dbQrJi0IHf


3️⃣ Icon Icons

- Over one thousand free icons which you can download as icons or images

🖇️ https://t.co/h5NlH5fGGr


4️⃣ Icons finder

Filter through the world’s largest marketplace for icons with flexibility and ease. Made up by submissions from top designers around the world, and curated by the team

🖇️ https://t.co/sqiZ6H9sR7
WEBDEV
Pratham
Pratham
@Prathkum
Use these 5 websites to learn web development for free in 2023 (take a look):

1. Codedamn

All-in-one platform for learning web development:

• Hands-on practice and projects bundled
• Video content along with interactive labs, quizzes, and articles
• Every course comes with a certificate
• code brushes AI in playgrounds

🔗 https://t.co/mXmUtJZnOU


2. Codepip

Codepip is the platform for your favorite web development games. Gain an edge in your following interview or project.

🔗 https://t.co/MjHNsLvkiL


3. RapidAPI Comics

Learn API development with RapidAPI Comics (sketch notes and fun analogies).

🔗 https://t.co/KONorFomgu


4. JS Visualizer 9000

Learn JavaScript by visualizing your code.

🔗 https://t.co/9NId4GjGAq
WEBDEV
Advertisement
George Moller
George Moller
@_georgemoller
🌟 2022 React developer roadmap.


1/4


2/4


3/4


4/4
WEBDEV
Sunil Kumar
Sunil Kumar
@sunilc_
Are you a web developer?

Here's a list of websites that offer free & beautiful website templates:

🧵👇🏻

1. HTML5UP: Very modern, unique responsive HTML5/CSS3 themes
https://t.co/Nx1IWM7Kho

2. Templatemo: Minimal, resume, gallery themes and more
https://t.co/IRtOxrujUh

3. Templated .co: Tons of minimalistic HTML5/CSS3

4. FreeHTML5: Free & premium HTML5 and Bootstrap themes
https://t.co/YFVkiDM3Th

5. StyleShout: Brilliantly crafted free website templates
https://t.co/AaGAkGlLTV

6. Start Bootstrap: Bootstrap starter

7. Zerotheme: HTML5, Bootstrap, Prestashop templates
https://t.co/UtlaNxGh6Q

8. HTML5xCSS3: Collection of wonderful templates in different categories
https://t.co/fm4AOthUdR

9. Colorlib: Almost any category of theme you can think

10: Free CSS: Huge collection of free templates
https://t.co/S5yQrkp1eq

11. Hubspot: Templates, infographics, banners and much more
https://t.co/T10zTgkIzp

12. Mobirise: Great looking HTML5/CSS3
WEBDEV
Pratham
Pratham
@Prathkum
Some of my handmade JavaScript notes and cheat sheets that can help you 🧵👇

1. JavaScript Function Anatomy


2. JavaScript Arrow Function


3. JavaScript Array Methods


4. JavaScript Date Methods
WEBDEV , ALL

You May Also Like

Greta Musk
Greta Musk
@GretaMusk
🚔 HUGE #Tesla SERVICE PROBLEMS THREAD🚔

You might remember my 3 prior threads on how
TESLA. TREATS. ITS. CUSTOMERS. LIKE. TRASH.

Here's the 4th installment.
@tomkeinan @jonsey_lisa @jwmooc @tchanpoker @bryanthediamond @EconomicManBlog
$TSLA $TSLAQ 1/22


Welcome to Greta's 4th edition of #Tesla customers getting used and abused. Because that's the Elon Musk way.
@coffeebreakls @KocgibiHarun @omaragha @JayGhahari
$TSLA $TSLAQ 2/22


"The best service is no service." - Elon Musk a.k.a. #SpaceKaren
@briansaziz @FarSha998899 @thinktankfour @Billoday1
#Tesla $TSLA $TSLAQ 3/22


These #Tesla customers represent just the very tip of the iceberg. They are ones who have Twitter, have decided to complain about their #TeslaServiceIssues publicly, and were found by yours truly.
@yanismydj @hajelatweets @AlanHeldman @francislongo5 $TSLA $TSLAQ 4/22


Dear #Tesla customers: In California, if your vehicle has been out of service for >30 days total, it's a lemon. You can get punitive damages and attorney's fees. Don't sit around and take Elon's abuse. @13arm13arm @cecimar12 @richardson_skip @shootinglee $TSLA $TSLAQ 5/22
TECH
SK
SK
@sk_diary1
A #story from #Thiruvilayadal puranam-one of divine leelas of Bhagwan Shiva

#threadseries #Madurai

Story 16- it is about how Bhagwan Shiva explained the meaning of Vedas to the Rishis.

வேதத்துக்குப் பொருள் அருளிச் செய்த படலம்


Once there was a great deluge,everything in the world was destroyed.All lifeforms that existed got perished.Afterwards ,due to Bhagwan Shiva creation started.Then from Bhagwan Shiv ji's mouth-birth of 🕉 OM- Pranavam happened.From Pranavam,4 vedas appeared. Rishis learned them.

Many Rishis in Naimisharanya learned Vedas&recited them but they didn't understand the meaning&essence of Vedas. They were worried as they couldn't find any guru who can teach them the meaning of Vedas.That time,Rishi Arabhatar visited them.Rishis told him about need their worry.

Rishi Arabhatar told them that Bhagwan Shiva has given Vedas &he would be grateful enough to teach the meaning as well.But for that rishis have to rigorous penance at a sacred place.Also told them to go to Sundareswarar temple in Madurai to do tapas in front of Dakshinamurthy.

Assured them that Dakshinamurthy himself will come & teach them.Rishis proceeded to Madurai & started their tapas in front of Dakshinamurthy sannidhi for almost a year starting from Karthigai month pournami to next year Karthigai month pournami following all rituals..annadan
ALL
Advertisement
KENYAN\U0001f1f0\U0001f1ea HISTORY\U0001f1f0\U0001f1ea
KENYAN🇰🇪 HISTORY🇰🇪...
@historykenya101
Have you ever wondered why the sons and daughters of the colonial chiefs and guards who were collaborators live a good life while those of the MAU MAU fighters live in abject poverty?

***THREAD***


It should be known that the colonialists reached a point that they knew they had 2 leave Kenya since they couldn't handle the Mau Mau war & the world was moving toward accepting independent Africa.However,the colonialists devised an evil scheme that still eats Kenya upto this day

Under this scheme, the colonial state came up with a plan that saw the first crop of chiefly “big men” being empowered financially to take their children to schools and eventually have those children go to England for further studies...

...and eventually providing a ready-made socio-economic & political class whom state power could be entrusted in the post-colonial era.This explains why their children & grandchildren still hold majority of important positions in govt or in the private sector supported by state.

This also explains why children and grandchildren of these homeguards are always given preferential treatment when it comes to government appointments. Wewe na masomo yako you are always asking why you can never get a job in government...yet you're qualified..now you know.
HISTORY
Vibhu Vashisth
Vibhu Vashisth
@VIBHU_Tweet
RANI NAIKI DEVI AND THE BATTLE OF KASAHRADA

Mohammad Ghori, the young Ghurid Prince conquered Ghaznavids in Afghanistan in the year 1173 CE. He conducted some successful raids into the Indian territory, which even Mahmud Ghazni & the Persians couldn't do.


First&foremost,Ghori invaded states of Multan &Uch in India.After this he turned to southern states of Gujarat &Rajputana.Everybody knows this about Ghori,but what most pple r unaware of is the defeat he suffered at hands of Chalukyan Queen Naiki Devi in 1178 Battle of Kasahrada.


When he marched southwards, his first target was the prosperous fortified town of Anhilwara Patan.
It was the capital of Chalukyas(also known as Solankis of Gujarat) which was established by Vanraj of Chapotkata Dynasty in 8th century.


American historian Tertius Chandler states that it was the 10th largest city in the world at that time. The history of Chalukyas has been written by many historians, but the valour of the Great Queen Naiki Devi remains unsung.


Born to the Kadamba King Paramardin of Goa,Naiki Devi was well trained in sword fighting, horse riding, strategy & every other subject of Statesmanship. She was married to King Ajaypala of Gujarat who sat on throne in 1171CE. Unfortunately,the King died within 4 yrs of his rule.
ALL
Alex Oluwatobi
Alex Oluwatobi
@alexlobaloba
According to psychologists, there are four types of intelligence:

- Intelligence Quotient (IQ)
- Emotional Quotient (EQ)
- Social Quotient (SQ)
- Adversity Quotient (AQ)

1. IQ is the measure of one's ability to comprehend, solve maths; memorize things & recall subject matters.

2. EQ is the measure of your ability to maintain peace with others; keep to time; be responsible; be honest; respect boundaries; be humble, genuine, and considerate.

3. SQ is the measure of one's ability to build a network of friends & maintain it over a long period of time.

4. AQ is the measure of your ability to go through a rough patch in life and come out without losing your mind. It is a new paradigm and can be used to determine who will give up in face of troubles and may abandon their families.

Now to the very interesting & analytical part👇

People that have higher EQ & SQ tend to go further in life than those with high IQ but low EQ &SQ.

Most schools capitalize on improving IQ level while EQ & SQ are played down.

A man of high IQ can end up being employed by a man of high EQ & SQ even though he has an average IQ.

Your EQ represents your character; your SQ represents your charisma. Give in to habits that will improve these three Qs but more especially your EQ and SQ.

EQ and SQ make one manage better than the other.

Try not only to have a higher IQ but also to have higher EQ and SQ.
ALL