# 11 American Axle & Manufacturing SQL Interview Questions (Updated 2024)

Updated on

June 30, 2024

American Axle & Manufacturing employees write SQL queries daily for analyzing manufacturing process data for efficiency improvements, and managing supply chain information. So, it shouldn't surprise you that American Axle & Manufacturing frequently asks SQL problems in interviews for Data Science and Data Engineering positions.

So, to help you study, here’s 11 American Axle & Manufacturing SQL interview questions – able to answer them all?

## 11 American Axle & Manufacturing SQL Interview Questions

### SQL Question 1: Identify Top Purchasing Customers

As a data analyst for American Axle & Manufacturing, you are tasked to identify the company's 'power users'. In this context, power users are those who have purchased the most products over the last 12 months. The goal is to calculate, for each user, their total amount spent, the number of unique products bought, and the maximum single transaction amount in the last 12 months.

##### Here are the input tables:

Example Input:

purchase_iduser_idpurchase_dateproduct_idamount
10112506/18/2021 00:00:0090001500.00
10226506/10/2021 00:00:0080752700.00
10336206/10/2021 00:00:0090001600.00
10419206/26/2022 00:00:0080752300.00
10598107/05/2022 00:00:0090001700.00

Example Input:

product_idproduct_nameproduct_type
90001AxleVehicle Component
80752TransmissionVehicle Component

For the SQL question, write a PostgreSQL query to solve this problem.

This SQL query aggregates the purchase_logs data for the last 12 months ('1 year' before the current date) at the user level. It calculates the total amount spent (), the number of unique products bought (), and the maximum amount spent in a single transaction () for each user. The results are ordered in descending order by the total amount spent to help identify the 'power users' who spent the most.

To solve a similar power-user data analysis problem question on DataLemur's free interactive SQL code editor, try this Microsoft Teams Power User SQL Interview Question:

### SQL Question 2: Employees Earning More Than Their Boss

Given a table of American Axle & Manufacturing employee salary data, write a SQL query to find employees who earn more money than their direct manager.

#### American Axle & Manufacturing Example Input:

employee_idnamesalarydepartment_idmanager_id
1Emma Thompson38001
2Daniel Rodriguez2230110
3Olivia Smith800018
4Noah Johnson680028
5Sophia Martinez1750110
8William Davis70002NULL
10James Anderson40001NULL

#### Example Output:

employee_idemployee_name
3Olivia Smith

This is the output because Olivia Smith earns \$8,000, surpassing her manager, William Davis who earns 7,800.

You can solve this problem and run your code right in DataLemur's online SQL environment:

First, we perform a SELF-JOIN where we treat the first table () as the managers' table and the second table () as the employees' table. Then we use a clause to filter the results, ensuring we only get employees whose salaries are higher than their manager's salary.

If the code above is confusing, you can find a step-by-step solution here: Employees Earning More Than Managers.

Check out the American Axle career page!

### SQL Question 3: What are the main differences between foreign and primary keys in a database?

To clarify the distinction between a primary key and a foreign key, let's examine employee data from American Axle & Manufacturing's HR database:

:

+------------+------------+------------+------------+ | employee_id| first_name | last_name | manager_id | +------------+------------+------------+------------+ | 1 | Aubrey | Graham | 3 | | 2 | Marshal | Mathers | 3 | | 3 | Dwayne | Carter | 4 | | 4 | Shawn | Carter | | +------------+------------+------------+------------+

In this table, serves as the primary key. It uniquely identifies each employee and cannot be null.

functions as a foreign key, linking to the of the employee's manager. This establishes a relationship between American Axle & Manufacturing employees and their managers, allowing for easy querying to find an employee's manager or see which employees report to a specific manager.

The table may also have multiple foreign keys that reference primary keys in other tables. For example, and foreign keys could be used to connect each employee to their respective department and location.

### SQL Question 4: Analysis of Production Defects

In the role of a Data Analyst at American Axle & Manufacturing, a company that designs, engineers and manufactures driveline and metal forming technologies, part of your role is to analyze the production line and identify defects trends for early warning and remediation.

Working with the Production database, you are asked to write a SQL query to determine the average defect rate for each product by month over the whole dataset. To accomplish this task, you will use SQL Window Functions in your query. The defect rate is the sum of defects for the product in a given month divided by sum of units produced for the same product and month.

The table has a row for each unit produced, and includes a boolean column that is if the unit was defective, and otherwise.

#### Example Input:

production_idproduct_idproduction_dateis_defective
10A102/01/2022 00:00:00false
15A102/04/2022 00:00:00true
20B202/01/2022 00:00:00false
25A102/06/2022 00:00:00true
30B202/10/2022 00:00:00false
35B203/01/2022 00:00:00false
40A103/02/2022 00:00:00false

#### Expected Output:

monthproductavg_defect_rate
2A10.6667
2B20.0000
3A10.0000
3B20.0000

Here is the SQL query to get the result.

In the SQL query above, the function is used to group data by month. Then we calculated, for each product and each month, the number of defects () and divided it by the total number of units produced (). The function was used to ensure that the division result is a decimal number. This gives us the average defect rate for each product by month.

To practice another window function question on DataLemur's free interactive SQL code editor, try this Google SQL Interview Question:

### SQL Question 5: What distinguishes a left join from a right join?

In SQL, both a left and right join is used to combine rows from different tables based on a shared key or set of keys, resulting in a single merged table of data. However, here's the difference:

LEFT (OUTER) JOIN: Retrieves all the records/rows from the left and the matched records/rows from the right table.

RIGHT (OUTER) JOIN: Retrieves all the records/rows from the right and the matched records/rows from the left table.

### SQL Question 6: Vehicle Production Management

American Axle & Manufacturing needs to manage its vehicle production. The company wants to be able to track the number of different type of vehicles produced each month and identify which plant produces the most of each vehicle type. Suppose you have two tables, and .

Table records each vehicle produced, with fields including (a unique identifier for the vehicle), (the type of vehicle), (the date the vehicle was produced), and (the identifier of the plant where the vehicle was produced).

Table includes details about each plant, with fields including (the identifier of the plant), (the plant's name), and (where the plant is located).

##### Example Input:
Vehicle_IDTypeProd_DatePlant_ID
1Sedan2022-06-01100
2SUV2022-06-05200
3Sedan2022-07-02100
4Truck2022-08-15200
5Sedan2022-08-30100
##### Example Input:
Plant_IDNameLocation
200Plant BChicago

The task: Write a SQL query to display a monthly break down of each type of vehicles produced and the plant that produced the most of each type.

This query first creates a CTE () to count the number of each type of vehicles produced at each plant, then creates another CTE () to find the maximum number of each type of vehicles produced each month. Finally, it joins and tables to get the plant that produced the most of each type for each month.

### SQL Question 7: What are the different kinds of joins in SQL?

A join in SQL allows you to retrieve data from multiple tables and combine it into a single set of results.

In SQL, there are four different types of JOINs. To demonstrate each kind, imagine you had two database tables, an advertising campaigns table which had information on Google Ads keywords and how much was bid for each keyword, and a sales table, which has data on how many products were sold and which Google Ads keyword drove that sale.

: An INNER JOIN retrieves rows from both tables where there is a match in the shared key or keys. For example, an INNER JOIN between the table and the table could be performed using the keyword column as the shared key. This would retrieve only the rows where the keyword in the table matches the keyword in the table.

: A LEFT JOIN retrieves all rows from the left table (in this case, the table) and any matching rows from the right table (the Sales table). If there is no match in the right table, values will be returned for the right table's columns.

: A RIGHT JOIN retrieves all rows from the right table (in this case, the Sales table) and any matching rows from the left table (the table). If there is no match in the left table, values will be returned for the left table's columns.

: A FULL OUTER JOIN retrieves all rows from both tables, regardless of whether there is a match in the shared key or keys. If there is no match, values will be returned for the columns of the non-matching table.

### SQL Question 8: Filter Customers Based on Region and Product Sales

You work as a data analyst at American Axle & Manufacturing, a leading provider of driveline and drivetrain systems and components for automotive manufacturers. Your team maintains a customer database that includes detailed information about each customer’s location, as well as their recent purchases.

Your task is to identify customers from the 'Southern' region who have purchased at least one Transmission System in the year 2021.

The data is stored in two tables, and .

#### Example Input:

customer_idregionname
123EasternABC Auto
234SouthernA-South Motors
345WesternWest Drives
456SouthernSOUTH-Wind

#### Example Input:

purchase_idcustomer_idproductpurchase_date
5671234Transmission System2021-08-12
6792345Engine Control Unit2021-10-09
5493456Transmission System2021-09-29
6242123Driveshaft2021-07-15
6327234Driveshaft2021-02-22

Write a SQL query to filter the data according to the conditions.

This PostgreSQL query first joins the and tables on the field. It then filters the joined table to include only the rows where the customer's region is 'Southern', the purchased product is 'Transmission System', and the year of the purchase is 2021. The function is used to extract the year from the column. The resulting table includes the IDs and names of the customers who meet all the criteria.

### SQL Question 9: Find Customers from Specific Region

American Axle & Manufacturing wants to target customers from the Midwestern United States for a direct marketing campaign. As an SQL expert, you are tasked with retrieving customer information who live in cities that are known to begin with 'Cha'. Write an SQL query to filter the relevant customer information from the table.

##### Example Input:
customer_idfirst_namelast_namecitystateemail
88JohnDoeChicagoIllinoisjohnd@example.com
17JaneDoeLos AngelesCaliforniajaned@example.com
43BobSmithChattanoogaTennesseebobsmith@example.com
29AliceJohnsonCharlotteNorth Carolinaalicej@example.com
55CharlieBrownCharlestonWest Virginiacharlieb@example.com
##### Example Output:
customer_idfirst_namelast_namecitystateemail
88JohnDoeChicagoIllinoisjohnd@example.com
43BobSmithChattanoogaTennesseebobsmith@example.com
29AliceJohnsonCharlotteNorth Carolinaalicej@example.com
55CharlieBrownCharlestonWest Virginiacharlieb@example.com

This query uses the SQL clause to find all records in the table where the name begins with 'Cha'. It uses the wildcard to match any sequence of characters after the string 'Cha', effectively filtering for cities that start with this pattern. The result is a table of customers living in such cities, useful for targeting direct marketing efforts.

### SQL Question 10: What are the similarities and differences between a clustered index and non-clustered index?

A clustered index is an index where the order of the rows in the database corresponds to the order of the rows in the index. Because of this, a table can only have one clustered index, but it can have multiple non-clustered indexes.

The main difference between the two is that the database tries to keep the data in the same order as the corresponding keys in the clustered index. This can improve the performance of most query operations, as it provides a linear-access path to the data stored in the database.

### SQL Question 11: Analyze Customer Purchase History and Match with Product Info

You are provided with two tables. The first table, , includes the list of all customers at American Axle & Manufacturing, along with the product_id of the items they've bought. The second table, , gives information about all the available products, including their name and category.

Your task is to write a SQL query to merge these two tables and find how many pieces are bought of each category by each customer. Sort your result by customer_id and category.

##### Example Input:
customer_idproduct_idquantity
11005
11023
21016
21001
31034
31012
##### Example Input:
product_idnamecategory
100"Axle""Car Parts"
101"Rotor""Car Parts"
102"Wheel""Car Parts"

This SQL query joins the 'Customers' and 'Products' tables based on the matching 'product_id'. It then groups the data by 'customer_id' and 'category', summing up the quantity for each group, providing the total quantity purchased for each category by each customer. Sorting by 'customer_id' and 'category' provides an organized view of the results.

Since join questions come up frequently during SQL interviews, try this Snapchat SQL Interview question using JOINS:

### Preparing For The American Axle & Manufacturing SQL Interview

The best way to prepare for a SQL interview, besides making sure you have strong SQL fundamentals, is to practice a ton of real SQL questions that were asked in recent job interviews. Beyond just solving the above American Axle & Manufacturing SQL interview questions, you should also solve the 200+ SQL coding questions which come from companies like FAANG (FB, Apple, Amazon, Netflix, Google).

Each SQL question has hints to guide you, full answers and crucially, there is an interactive coding environment so you can right in the browser run your query and have it graded.

To prep for the American Axle & Manufacturing SQL interview you can also be wise to practice SQL problems from other automotive companies like:

But if your SQL query skills are weak, don't worry about jumping right into solving questions – strengthen your SQL foundations with this free SQL for Data Analytics course.

This tutorial covers SQL concepts such as LEAD window function and math functions in SQL – both of which show up often in American Axle & Manufacturing SQL assessments.

### American Axle & Manufacturing Data Science Interview Tips

#### What Do American Axle & Manufacturing Data Science Interviews Cover?

In addition to SQL query questions, the other types of problems to prepare for the American Axle & Manufacturing Data Science Interview are:

#### How To Prepare for American Axle & Manufacturing Data Science Interviews?

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