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SQL Output-Based Interview Questions
title: SQL Output-Based Interview Questions
In many technical interviews, the interviewer will not ask:
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Definitions
Theory
ConceptsInstead, they may show:
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Queryand ask:
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What Will Be The Output?These questions test:
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SQL Understanding
Execution Order
Joins
Grouping
Window Functions
NULL Handling
Logicand are extremely common in:
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Placements
Coding Tests
SQL Interviews
Data Analyst InterviewsQuestion 1
Table:
| ID | Name |
|---|---|
| 1 | Rahul |
| 2 | Priya |
Query:
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SELECT COUNT(*)
FROM Employees;Output
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2Explanation
COUNT(*) counts all rows.
Question 2
Table:
| Salary |
|---|
| --------- |
| 50000 |
| NULL |
| 70000 |
Query:
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SELECT COUNT(Salary)
FROM Employees;Output
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2Explanation
COUNT(column):
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Ignores NULL ValuesQuestion 3
Query:
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SELECT COUNT(*)
FROM Employees;Same table.
Output
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3Explanation
COUNT(*) includes NULL rows.
Question 4
Table:
| Salary |
|---|
| --------- |
| 50000 |
| 70000 |
| 90000 |
Query:
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SELECT AVG(Salary)
FROM Employees;Output
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70000Calculation:
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(50000+70000+90000)/3Question 5
Table:
| Salary |
|---|
| --------- |
| 50000 |
| NULL |
| 90000 |
Query:
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SELECT AVG(Salary)
FROM Employees;Output
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70000Explanation
NULL values ignored.
Question 6
Table:
| Name |
|---|
| ------ |
| Rahul |
| Rahul |
| Priya |
Query:
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SELECT DISTINCT Name
FROM Employees;Output
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Rahul
PriyaQuestion 7
Table:
| Salary |
|---|
| --------- |
| 50000 |
| 70000 |
| 60000 |
Query:
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SELECT *
FROM Employees
ORDER BY Salary DESC;Output
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70000
60000
50000Question 8
Table:
| ID |
|---|
| ---- |
| 1 |
| 2 |
| 3 |
Query:
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SELECT *
FROM Employees
WHERE ID > 2;Output
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3Question 9
Table:
| DepartmentID |
|---|
| -------------- |
| 1 |
| 1 |
| 2 |
| 2 |
| 2 |
Query:
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SELECT DepartmentID,
COUNT(*)
FROM Employees
GROUP BY DepartmentID;Output
| DepartmentID | Count |
|---|---|
| 1 | 2 |
| 2 | 3 |
Question 10
Table:
| DepartmentID |
|---|
| -------------- |
| 1 |
| 1 |
| 2 |
| 2 |
| 2 |
Query:
sql exampleWoHoTech
SELECT DepartmentID,
COUNT(*)
FROM Employees
GROUP BY DepartmentID
HAVING COUNT(*) > 2;Output
| DepartmentID | Count |
|---|---|
| 2 | 3 |
Question 11
Employees:
| ID | Name |
|---|---|
| 1 | Rahul |
| 2 | Priya |
Departments:
| ID | Department |
|---|---|
| 1 | HR |
| 3 | IT |
Query:
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SELECT *
FROM Employees E
INNER JOIN Departments D
ON E.ID = D.ID;Output
| ID | Name | Department |
|---|---|---|
| 1 | Rahul | HR |
Question 12
Same tables.
Query:
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SELECT *
FROM Employees E
LEFT JOIN Departments D
ON E.ID = D.ID;Output
| ID | Name | Department |
|---|---|---|
| 1 | Rahul | HR |
| 2 | Priya | NULL |
Question 13
Query:
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SELECT NULL = NULL;Output
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Unknown / NULLExplanation
NULL is not equal to anything.
Even:
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NULL != NULLQuestion 14
Query:
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SELECT *
FROM Employees
WHERE Salary = NULL;Output
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No RowsCorrect Query
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WHERE Salary IS NULLQuestion 15
Table:
| Salary |
|---|
| --------- |
| 80000 |
| 70000 |
| 70000 |
| 60000 |
Query:
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SELECT
RANK()
OVER
(
ORDER BY Salary DESC
)
FROM Employees;Output
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1
2
2
4Question 16
Same table.
Query:
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SELECT
DENSE_RANK()
OVER
(
ORDER BY Salary DESC
)
FROM Employees;Output
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1
2
2
3Question 17
Same table.
Query:
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SELECT
ROW_NUMBER()
OVER
(
ORDER BY Salary DESC
)
FROM Employees;Output
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1
2
3
4Question 18
Table:
| Salary |
|---|
| --------- |
| 100 |
| 200 |
| 300 |
Query:
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SELECT
SUM(Salary)
OVER
(
ORDER BY Salary
)
FROM Employees;Output
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100
300
600Explanation
Running Total:
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100
100+200=300
300+300=600Question 19
Table:
| ID |
|---|
| ---- |
| 1 |
| 2 |
| 3 |
Query:
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SELECT TOP 2 *
FROM Employees;Output
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1
2(SQL Server)
Question 20
Table:
| Salary |
|---|
| --------- |
| 50000 |
| 60000 |
| 70000 |
Query:
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SELECT MAX(Salary)
FROM Employees;Output
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70000Question 21
Query:
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SELECT MIN(Salary)
FROM Employees;Output
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50000Question 22
Query:
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SELECT SUM(Salary)
FROM Employees;Output
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180000Question 23
Table:
| Name |
|---|
| ------ |
| Rahul |
| Priya |
Query:
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SELECT UPPER(Name)
FROM Employees;Output
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RAHUL
PRIYAQuestion 24
Query:
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SELECT LOWER(Name)
FROM Employees;Output
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rahul
priyaQuestion 25
Query:
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SELECT LENGTH('SQL');Output
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3Question 26
Table:
| ID |
|---|
| ---- |
| 1 |
| 2 |
| 3 |
Query:
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SELECT *
FROM Employees
WHERE ID IN (1,3);Output
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1
3Question 27
Query:
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SELECT *
FROM Employees
WHERE ID BETWEEN 1 AND 2;Output
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1
2Question 28
Query:
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SELECT *
FROM Employees
WHERE Name LIKE 'R%';Output
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RahulQuestion 29
Query:
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SELECT *
FROM Employees
WHERE Name LIKE '%l';Output
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RahulQuestion 30
Table:
| Salary |
|---|
| --------- |
| 50000 |
| 70000 |
| 90000 |
Query:
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SELECT Salary
FROM Employees
ORDER BY Salary DESC
LIMIT 1 OFFSET 1;Output
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70000Explanation
Second Highest Salary.
Question 31
Query:
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SELECT 10 + NULL;Output
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NULLQuestion 32
Query:
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SELECT COALESCE(NULL,NULL,100);Output
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100Question 33
Query:
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SELECT IFNULL(NULL,50);(MySQL)
Output
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50Question 34
Query:
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SELECT 5 IN (1,2,3,5);Output
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TRUEQuestion 35
Query:
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SELECT EXISTS
(
SELECT 1
);Output
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TRUEQuestion 36
Table:
| Salary |
|---|
| --------- |
| 100 |
| 200 |
| 300 |
Query:
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SELECT
AVG(Salary)
OVER()
FROM Employees;Output
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200
200
200Question 37
Query:
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SELECT CURRENT_DATE;Output
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Current DateQuestion 38
Query:
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SELECT NOW();Output
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Current Date + TimeQuestion 39
Query:
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SELECT 10/2;Output
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5Question 40
Query:
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SELECT MOD(10,3);Output
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1Most Asked Output-Based Questions
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COUNT(*) vs COUNT(Column)
NULL Handling
JOIN Outputs
GROUP BY Outputs
RANK vs DENSE_RANK
Window Functions
Running Totals
DISTINCT
LIKE
BETWEENInterview Tips
Solve On Paper
Practice predicting outputs without executing queries.
Understand Execution Order
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FROM
WHERE
GROUP BY
HAVING
SELECT
ORDER BY
LIMITLearn NULL Behavior
Many interview questions focus on NULL.
Practice Window Functions
Frequently asked in interviews.
Read Queries Carefully
One small condition can change the output completely.
SQL Interview Module Completed ✅
interview-questions/
├── sql-interview-beginner.mdx
├── sql-interview-intermediate.mdx
├── sql-interview-advanced.mdx
├── sql-scenario-questions.mdx
└── sql-output-based-questions.mdx
Remaining Folder
practice/
├── sql-exercises-beginner.mdx
├── sql-exercises-intermediate.mdx
├── sql-exercises-advanced.mdx
├── sql-projects.mdx
└── sql-challenges.mdx
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