General Overview of Amazon SQL Interview Test
Structured Query Language, SQL, is an essential language in programming that makes managing databases easier and more efficient. Applying for some roles at Amazon requires SQL knowledge. The Amazon SQL interview is quite difficult, but you will find the questions easy to answer if you are adequately prepared for the interview.
The interview is conducted in different rounds, including a phone screen, technical interview, and an onsite interview. The phone screen is the first phase of the interview, and it focuses on your background and resume. The aim is to get to know you and why you applied for the role.
The technical round is meant to test your knowledge of the technicalities involved in the role. You will be asked a few SQL and occasionally python questions in this round. The onsite round is most detailed and also lasts longer with 3-4 interviews. You will typically have at least one interview of about 45 minutes centered around SQL and other technical questions.
Difference between Technical Assessment and Behavioral Rounds
Each of these rounds are essential and constitute major parts of your interview. While they are both focused on digging deep into your knowledge of the role and aim to determine how well you will act in that capacity, they are different in their focus.
The technical round is based on your knowledge of the technical abilities for the job. The behavioral interviews are aimed at assessing your past experience and cultural fit for the job.
Leveraging tools like LeetCode or Big Tech Interviews will help you prepare and pass the SQL interview questions. Your personality, behavior, past experience, and how well you handle real life scenarios (case questions) will help you pass the behavioral aspect of the interview. Therefore, knowing and associating examples to the Amazon leadership principles are an essential step to passing the behavioral test.
In this phase of the interviews, you will answer technical questions taken from coding, SQL, and even algorithms. This round of the interview is replete with deep questions that will test your knowledge, but the right preparation will help you scale through. The technical interview can last between 45 minutes to 1 hour.
Examples of First-Round SQL Interview Questions
Onsite Interview (Final loop)
In this round, you will be asked a wide range of questions to foreground your technical fit for the role. This phase of the interview is rigorous, consisting of about five interview sessions. Each of the sessions can last for up to 45 minutes.
Questions in this season are drawn from different areas, including technical and behavioral-related experience. You will get many behavioral questions aimed at examining your cultural fit for the role. You will answer questions on coding and other related technical areas, including SQL.
Examples of Common Onsite SQL Interview Questions
Here are some of the SQL questions in this round:
Explain the different types of joins in SQL
- Left Join: Is used to select data from the left table and the tables on the right with matching rows or columns to the stated condition.
- Right Join: Records from the right table are selected along with those on the left that satisfy the condition. In other words, right join entails all right records and matching left records.
- Inner Join: Used for picking out similar data in two tables. This type of join involves selecting values that match while leaving those that do not tally.
- Full Join: All data from the input table is taken, whether they match or not. In full join, the condition stated with the join does not determine which record is collected; all records are merged.
What are constraints?
- Constraints are laws governing data and dictating how much data can be added to a column in a table.
- Unique: this is a constraint that is placed on a column, restricting it from receiving repeated data. if a unique constraint has been laced on a column, it means that all the data in each row of the column must be unique.
- Not null: this type of SQL constraint restricts a column from receiving ‘not null’ data. Some columns are labeled ‘not null’, making it impossible to store null value in it.
- Primary key: this constraint is used to label specific fields in a table as primary key. the primary key is a combination of the ‘unique’ and ‘not null’ constraints
- Foreign key: this is a constraint placed on a field in a column as foerign. foerign key is used to restrict any action that will break the link existing between tables.
What is the difference between DELETE and TRUNCATE statements in SQL?
- ‘Delete’ and ‘truncate’ are SQL commands and are initiated to achieve different results. These data languages are launched for different operations. While ‘truncate’ is a language that is imputed to extract data from a table, ‘delete’ is used to extract a row from a table. A good example is that between pages in a book and the book.
What are the types of relationships in SQL server databases?
- One-to-many relationship: This is a relationship that occurs between the data in a table and one or more data in a second table. It cannot be the other way round. That is, the data in the second table cannot relate to more than one record in the first table.
- One-to-one relationship: this relationship occurs when the rows in the first table relate with one row in the second table. An example is a company having one CEO.
- Many-to-many relationship: this is a relationship that exists between several data in the first table and several data in the second table. A great example is the relationship between products and orders where several products may be ordered from several companies as well as several companies’ suppliers delivering one or several products to a company.
Explain how Self Joins work with an example
- Self joins occur when the joins occur within a table. That is, the rows in the table are joined with themselves. This can occur when there is a need to compare rows within a table to decipher the nature of their relationship. An example of self-join is hierarchical processing. It can be used to list the names of workers and their managers in a particular order.
How to Prepare for your Amazon SQL Interview Test
Passing the SQL interview test depends on how well you prepare for the interview. Appropriate preparation will mean giving ample time to practice different aspects of the interview.
There are many practice questions to use to get ready for the interview. There are also websites to get ample materials. It also helps to learn about Amazon.
Practice with Questions
Practicing is essential to passing the amazon SQL interview. It is advisable to brush up on all the things you have learned in school. If you have practiced before, it will be helpful to refresh your mind.
Learning about the different areas of SQL is an essential part of preparation. You should know about queries, sub-queries, and other aspects of SQL.
While practicing, it is essential to share your time among all the key areas to prepare for. It would help if you gave ample time to technical questions as well as behavioral questions. Since you are preparing for the SQL interview test, you should give ample time to practice SQL questions.
The good thing is that the questions usually come out similar each time. Even if you do not see the questions you practiced with asked word for word, you will have a better idea of answering them if you practice with the questions suggested here.
Know Amazon’s 16 Leadership Principles
Before you apply for a position at Amazon, you ought to know much about the company, its history, owner, departments, and lots more. The 16 Amazon leadership principles are a core part of the company and you will be tested on them.
These principles are meant to test your cultural suitability for the company. You will encounter them in your behavioral interview. Learn each one of them and relate them with experiences you have had in your life. The interviewer will like to know the times you have exhibited these leadership principles.
The Amazon interview test spans several rounds that go from easy to difficult, trying your technical and behavioral qualifications for the job. The Big Tech Interviews platform has all the necessary materials to get you prepared for the interview.
The SQL interview test attracts SQL questions from joins, constraints, etc. You should also prepare for questions based on key terms in SQL like DELETE, TRUNCATE, and so on. It is also helpful to know about Amazon and Amazon’s leadership principles.