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SQL Interview Preparation

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1.Get Started

2.CRUD Operations

Question: Insert a Record Answer: Insert a Record Question: Update a Value Answer: Update a Value Question: Delete a Record Answer: Delete a Record

3.Aggregate Functions

Question: Aggregate Records Using SUM Answer: Aggregate Records Using SUM Question: Aggregate Records Using AVG Answer: Aggregate Records Using AVG Question: Aggregate Records Using MIN/MAX Answer: Aggregate Records Using MIN/MAX Question: Aggregate Records Using COUNT Answer: Aggregate Records Using COUNT

4.Date and Time Functions

Question: Extract a Value From a Date Answer: Extract a Value From a Date Question: The DATE Column and Calculations Answer: The DATE Column and Calculations

5.Filtering

Question: Filter with the WHERE Clause Answer: Filter with the WHERE Clause Question: Filter with the LIKE Operator Answer: Filter with the LIKE Operator

6.Grouping

Question: The GROUP BY Clause and the AVG Function Answer: The GROUP BY Clause and the AVG Function Question: The GROUP BY Clause and the SUM Function Answer: The GROUP BY Clause and the SUM Function

7.Sorting

Question: Sorting the Records Answer: Sorting the Records Question: Sorting and Calculations Answer: Sorting and Calculations

8.Constraints

Question: The NOT NULL Constraint Answer: The NOT NULL Constraint Question: The UNIQUE Constraint Answer: The UNIQUE Constraint Question: The PRIMARY KEY Constraint Answer: The PRIMARY KEY Constraint Question: The FOREIGN KEY Constraint Answer: The FOREIGN KEY Constraint

9.Working with JOINs

Question: Using LEFT JOIN Answer: Using LEFT JOIN Question: Using RIGHT JOIN Answer: Using RIGHT JOIN Question: Using INNER JOIN Answer: Using INNER JOIN Question: Combining JOIN Statements Answer: Combining JOIN Statements

10.Subquery

Question: Subquery in the SELECT Clause Answer: Subquery in the SELECT Clause Question: Subquery and Calculations Answer: Subquery and Calculations

11.Final Remarks

SQL Interview Preparation

Question: Using INNER JOIN

Learn how to apply the INNER JOIN on the tables.

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Question
Expected output
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Hints

Question

Given the following Employees, Skills, and Projects table structure:

Employees

EmpID	EmpName	Salary
1	Susan Lee	50000.00
2	Alexa Smith	60000.00
3	Sana Amberson	45000.00
4	Sarah Ronald	47000.00

Skills

SkillID	EmpID	SkillName
1	1	C++
2	4	Java
3	1	Python
4	3	Blender
5	NULL	Android

Projects

ProjectID	EmpID	SkillID	ProjectName
1	1	1	Industrial Robot
2	4	2	Multiplatform GUI
3	3	4	3D Simulation
4	1	3	Deep Learning Model
5	NULL	NULL	IOS App
6	1	NULL	Advanced Calculator
7	NULL	5	Android App

Additional information

The Employees table contains the following columns:

EmpID: Unique identifier for each employee ...