SQL Roadmap from Zero to Advance

Improve your database skills with this SQL online test! This SQL mock test evaluates your knowledge of fundamental SQL concepts, queries, and database management.

SQL Online Test

Summarized sales data with regional subtotals and grand total.

Error because WITH ROLLUP cannot be used with WHERE.

Only regions where sales are greater than 1000.

Given the table Sales, what will the following query return?
SELECT Region, SUM(Sales) 
FROM Sales
WHERE Sales > 1000
GROUP BY Region
WITH ROLLUP;


What is the purpose of the EXISTS keyword  ?

UNION removes duplicates, while UNION ALL keeps them.

UNION ALL removes duplicates, while UNION keeps them.

What is the difference between UNION and UNION ALL?

Returns employees reporting directly to their managers.

Returns a hierarchical tree structure of employees.

What does the following SQL query return?
SELECT EmployeeID, ManagerID
FROM Employees
CONNECT BY PRIOR EmployeeID = ManagerID;


Returns departments with at least 10 employees.

Returns only employees with more than 10 years of experience.

What does this query do?
SELECT Department, COUNT(*) 
FROM Employees
GROUP BY Department
HAVING COUNT(*) > 10;


Which SQL command is used to remove duplicate records from the result set?


First non-null value from Phone, Email, or 'No Contact'.

Returns NULL if both Phone and Email are NULL.

What will this SQL query return?
SELECT Name, COALESCE(Phone, Email, 'No Contact') 
FROM Customers;


What will happen if you run the following query?
DELETE FROM Orders
WHERE OrderID IN (SELECT OrderID FROM Orders WHERE CustomerID = 5);


Returns employees with above-average salaries.

Returns employees with below-average salaries.

What does the following SQL query do?
SELECT *
FROM Employees
WHERE Salary > (SELECT AVG(Salary) FROM Employees);


Assigns a unique rank without skipping numbers for duplicates.

Assigns the same rank for duplicate values but skips the next rank.

Returns the total number of rows in a table.

What is the purpose of the DENSE_RANK() function in SQL?

What is the result of the following SQL statement?
SELECT NULL = NULL;

Returns the total salary for each department.

Returns an error due to the missing GROUP BY.

Returns the total salary of all employees

Returns one row per department with summed salaries.

What happens if you execute this SQL statement?
SELECT EmployeeID, Department, SUM(Salary) 
FROM Employees;


Returns the first employee's name and count per department.

What will the following query do?
SELECT Name, COUNT(*) OVER (PARTITION BY Department) 
FROM Employees;


Orders by count of employees in ascending order.

Orders by count of employees in descending order.

What is the result of the following query?
SELECT Department, COUNT(EmployeeID) 
FROM Employees 
GROUP BY Department 
ORDER BY 2 DESC;

Returns the count of orders between the given dates.

Returns the count only if it's greater than 100.

What will be the output of the following SQL query?
SELECT COUNT(*)
FROM Orders
WHERE OrderDate BETWEEN '2024-01-01' AND '2024-12-31'
HAVING COUNT(*) > 100;
