11 Amdocs SQL Interview Questions (Updated 2024)

At Amdocs, SQL does the heavy lifting for extracting and analyzing customer data to improve telecom services. Unsurprisingly this is why Amdocs asks SQL questions during interviews for Data Science, Data Engineering and Data Analytics jobs.

To help you ace the Amdocs SQL interview, we've collected 11 Amdocs SQL interview questions – can you solve them?

11 Amdocs SQL Interview Questions

SQL Question 1: Identify VIP Customers of Amdocs

Amdocs is a multinational corporation dealing with software and services for communications, media and financial services providers, and digital enterprises. Let's say a VIP customer for Amdocs is a customer who has made more than 100 transactions in the last six months. Write a SQL query to identify these VIP customers.

Example Input:

* Assume that the is an example of an activity that's very important (i.e., revenues from the transactions) to Amdocs

Answer:

The above query will select customers from the table who have more than 100 transactions in the past 6 months. It also calculates the total revenue from each customer within this time frame. The result is ordered by the total revenue in descending order, giving you the customers with the highest revenue at the top of the list.

To solve a super-customer analysis question on DataLemur's free online SQL coding environment, try this Microsoft SQL Interview problem:

SQL Question 2: Calculate Monthly Average Rating for Each Product

As an analyst at Amdocs, telecom software and service provider, your task is to periodically analyze the customer satisfaction rating for each product. Assume you have a dataset representing product reviews submitted by users.

The table have the following columns:

• : unique id for review (primary key)
• : id of customer given the review
• : timestamp of when review submitted (format: mm/dd/yyyy hh:mm:ss)
• : unique id for product
• : customer satisfaction rating (1-5, where 5 represents high satisfaction and 1 low)

Write a SQL query that calculates a monthly average rating (stars) for each product. Consider only "month" and "year" for the timestamp.

Example Input:

Answer:

This query will display the month, year, product_id and the average of stars for each product per month and year. We used the function to break down the into months and years, then we grouped our results by these elements and by , and finally, we ordered our results by , and . This way, we get the ratings for each product organized by month and year, showing a temporal progression of customer satisfaction for each product.

For more window function practice, solve this Uber SQL problem within DataLemur's interactive coding environment:

SQL Question 3: Could you explain what a self-join is?

A self-join is a type of join in which a table is joined to itself. To perform a self-join, you need to specify the table name twice in the clause, and give each instance of the table a different alias. You can then join the two instances of the table using a clause, and use a clause to specify the relationship between the rows.

For example, say you were doing an HR analytics project and needed to analyze how much all Amdocs employees in the same department interact with each other. Here's a self-join query you could use to retrieve all pairs of Amdocs employees who work in the same department:

This query returns all pairs of Amdocs employees who work in the same department, and excludes pairs where the employee's id is the same (since this would represent the same Amdocs employee being paired with themselves).

SQL Question 4: Customer Subscription Data Analysis

Amdocs is a company that provides software and services for communications, media and financial services providers and digital enterprises. Let's say you're a data analyst at Amdocs, and you need to analyze the subscription data of a newly implemented feature for a particular service.

The two main tables you have to work with are (which contains information about the subscriber) and (which contains details about each subscriber's subscription to the new service).

Example Input:

Example Input:

Your task for this SQL interview question is to write a query that lists all subscribers who have a subscription for the new feature (feature_id = 3) and also calculates the duration of their subscription in days.

Answer:

Here's how you might solve this using SQL:

This query joins the and tables on the column and filters for only those rows where the is (indicating they subscribed to the new feature). It also calculates the duration of their subscription in days by subtracting the from the .

SQL Question 5: What's the SQL command do, and when would you use it?

Similar to the and / operators, the PostgreSQL INTERSECT operator combines result sets of two or more statements into a single result set. However, only returns the rows that are in BOTH select statements.

For a concrete example, say you were on the Sales Analytics team at Amdocs, and had data on sales leads exported from both HubSpot and Salesforce CRMs in two different tables. To write a query to analyze leads created after 2023 started, that show up in both CRMs, you would use the command:

SQL Question 6: Filter Amdocs Customers based on Conditions

In our customer database for Amdocs, we have a table 'Customers' and a table 'Subscriptions'. The 'Customers' table contains general information about our customers such as their 'customer_id', 'name', 'email', and 'location'. The 'Subscriptions' table contains information about what subscription each customer has with 'subscription_id', 'customer_id', 'start_date', 'end_date', and 'subscription_type'.

The task is to write a SQL query that will list all Amdocs customers located in 'New York' or 'New Jersey', who have a 'premiere' type subscription, and is currently active. Also provide an alternate solution to list all customers who do not match these conditions.

Example Input:

Example Input:

A suitable date for the query can be '20/11/2022'

Answer:

First query would list all customers in New York or New Jersey that have a Premiere subscription type and have an active subscription with respect to the chosen date.

Second query being an inverse of the first query, would list all customers that do not match the conditions in the first query, i.e., those who are not located in 'New York' or 'New Jersey', or do not have a 'Premiere' subscription, or whose subscription is not active on the given date.

SQL Question 7: What is the function of a primary key in a database?

The primary key of a table is a column or set of columns that serves as a unique identifier for each row. It ensures that all rows are distinct and does not allow null values.

For example, say you had stored some Facebook ad campaign data that Amdocs ran:

The column uniquely identifies each row in the table, and the PRIMARY KEY constraint ensures that no two rows have the same . This helps to maintain the integrity of the data in the table by preventing duplicate rows.

The primary key is also an important part of the table because it allows you to easily identify and reference specific campaigns in your Facebook Ad data. You can use it to join to other tables in the database, such as a table containing data on the results of the campaigns.

SQL Question 8: Determine Average Duration of a Service Interruption

As a database engineer at Amdocs, a company specializing in software and services for communications, media and financial services providers, you may be asked to find out the average duration of a service interruption experienced by customers.

Assume there is a table called "service_interruptions" with the following structure and sample data:

Example Input:

The task is to write a PostgreSQL query that computes the average duration of service interruptions for each of the services.

Answer:

This query begins by selecting the field from the table. The function, along with the keyword, is used to convert the duration between and into seconds. That result is then divided by 60 to convert the duration to minutes. The aggregate function is then used to find the average duration per service_id, and allows us to do this for each unique service_id. This will give us the average duration of a service interruption per service in minutes.

To practice a very similar question try this interactive Amazon Server Utilization Time Question which is similar for calculating durations or this Verizon International Call Percentage Question which is similar for dealing with service interruptions.

SQL Question 9: Filtering Customer Records

Given a database containing customer records for Amdocs, write a SQL query that filters out customers whose email addresses contain the word 'test'. Assume the database has a 'customers' table that has 'customer_id', 'first_name', 'last_name', and 'email'.

Example Input:

Answer:

In PostgreSQL, you can use the LIKE operator to filter records based on a specific pattern.

This query will return all records in the 'customers' table where the 'email' field does not contain the string 'test'.

Example Output:

In the above result, customers with 'test' in their email addresses are successfully filtered out.

SQL Question 10: What would you do to speed up a slow SQL query?

First things first, figure out why the query is slow! You can use and commands in PostgreSQL to identify any performance bottlenecks. You might discover that your query is inefficient, or that there are many database writes at the same time you are doing a read, or maybe too many people are concurrently running queries on the same database server.

For Data Analyst and Data Science positions, knowing the ins-and-outs of SQL performance tuning is out-of-scope for the SQL interview round. However, knowing that joins are expensive, and indexes can speed up queries, is generally enough of an answer for Amdocs SQL interviews.

SQL Question 11: Find the Total Amount of Sale of Each Product

Amdocs has two main databases - a customer database, and a sales database. The customer database consists of the customer_id and the customer name. The sales database consists of the product_id, the product name, the customer_id, and the price of the product (for each individual sale).

Write a SQL query to join these two tables and determine total sales for each product (including product_id and product name) by summing up the prices of each individual sale. The output should be ordered by the product_id.

Example Input:

Example Input:

Example Output:

Answer:

The PostgreSQL query to solve this problem would be:

This query first performs an inner join on the sales and customers tables on the customer_id field. It then groups the data by product_id and product_name, and finds the sum of the price column for each group. The result is ordered by product_id.

Since joins come up so often during SQL interviews, try this interactive Snapchat JOIN SQL interview question:

Preparing For The Amdocs SQL Interview

Assuming that you've already got basic SQL skills, the next best tip we have to prepare for the Amdocs SQL interview is to solve as many practice SQL interview questions as you can! In addition to solving the earlier Amdocs SQL interview questions, you should also solve the 200+ SQL questions on DataLemur which come from companies like FAANG and tech startups.

Each problem on DataLemur has multiple hints, fully explained answers along with a discussion board to see how others solved it and most importantly, there's an online SQL coding environment so you can easily right in the browser your query and have it graded.

To prep for the Amdocs SQL interview you can also be a great idea to practice SQL questions from other tech companies like:

• CSG Systems SQL questions

• NETSCOUT SQL questions

• Subex SQL questions

• Nucleus Software SQL questions

In case your SQL coding skills are weak, don't worry about going right into solving questions – strengthen your SQL foundations with this DataLemur SQL tutorial.

This tutorial covers SQL concepts such as UNION and CASE/WHEN statements – both of these show up frequently in Amdocs interviews.

Amdocs Data Science Interview Tips

What Do Amdocs Data Science Interviews Cover?

Besides SQL interview questions, the other types of problems covered in the Amdocs Data Science Interview are:

• Probability & Statistics Questions
• Python Pandas or R Coding Questions
• Product Data Science Interview Questions
• ML Modelling Questions
• Behavioral Interview Questions

How To Prepare for Amdocs Data Science Interviews?

The best way to prepare for Amdocs Data Science interviews is by reading Ace the Data Science Interview. The book's got:

• 201 Interview Questions from tech companies like Google & Microsoft
• A Crash Course on Python, SQL & ML
• Amazing Reviews (900+ reviews, 4.5-star rating)