Let's Chat

Top 31 SQL Interview Questions for Data Analysts Updated for 2023

You have a table of users’ impressions of ad campaigns over time. Each user_id from these campaigns has an attached impression_id, categorized as either “Excited” or “Bored”. You will need to assess which users are “Excited” by their most recent campaign and have never been “Bored” in any past campaign.

As you prepare your answer, take a look at the original job description. This helps you focus on the data that matters so you’re not distracted by the data that is irrelevant to the query. Queries like SELECT queries, which are frequently used to fetch a data set from a database, can be recorded as a Stored Procedure. The SQL query saved within the Stored Procedure is executed when the Stored Procedure is called.

Leave a Reply Your email address will not be published. Required fields are marked *

For example, you could create a view that only includes customer information that is relevant to your current project. Tables, on the other hand, are database structures that actually store data. An index is a database management system that is used to improve the performance of SQL queries. Indexes can be created on columns in a table, and they are typically used to speed up searches for specific values in those columns.

A primary key is a column or set of columns that uniquely identify a row in a table. Primary keys must contain unique values, and they cannot be NULL. The WHERE clause is used to filter rows from a table based on specified conditions; for example, you could use a WHERE clause to find all customers who live in a particular city.

Define a SQL term

A SQL join is used to combine data from two or more tables into a single result set. Joins are performed using the JOIN keyword, followed by the name of the table to join with. There are a number of different types of joins, including inner joins, outer joins, and self-joins. Inner joins return rows from both tables that have matching values in the specified columns, while outer joins return all rows from both tables, including rows with no matching values. Self-joins are used to join a table to itself; for example, you could use a self-join to find all customers who live in the same city as another customer. Data analyst roles have become extremely popular in recent times.

  • The experience you highlight doesn’t have to come from a job.
  • If you’re looking for more SQL interview prep, here are some free resources where you can practice writing queries.
  • With each update, you can expect to access new questions, providing you with fresh opportunities to enhance your skills and knowledge.
  • For example, you could use a window function to calculate the average order total for each customer.
  • You may be asked to present your results in a Jupyter notebook or through a short slide deck presentation.

The BETWEEN operator is used to select values within a range. SQL Server supports both user-defined and built-in stored procedures. Also, you can provide a variety of parameters to a Stored Procedure. The HAVING clause https://wizardsdev.com/en/vacancy/sql-and-data-analyst-bi-analyst/ is used after the GROUP BY clause in the query to put a constraint on the GROUP Function. Determine the difference between NVL and NVL2 functions. Create a SQL query to determine the table’s nth highest income.

Amazon Data Engineer Interview Questions

You can do an inner join on all 3 tables since the question states that the flight_purchases table does not have entries of flights or seats that do not exist. Although there are a few steps to the solution, the actual SQL queries are fairly simple. For this medium SQL problem, assume you work at an advertising firm.

sql interview questions and answers for data analyst

As you prepare to interview for data analyst jobs, you can expect that SQL will come up during the job interview process. If you’re hustling to gain that hands-on experience before your interview, we’ve got you covered. Interested in becoming a data analyst but concerned about the data analyst interview questions and answers. Spreadsheets are amongst the common tools used by data analysts. Interviews often include one or more questions meant to gauge your skill in working with data in Microsoft Excel.

Domain knowledge for QA Tester

If there’s a more efficient way you could have written your code—using subqueries, for example—explain that. The interview concluded with an opportunity for me to ask questions about the company, the team, and the role. I also received information about the next steps in the hiring process. Please note that we are constantly updating our questions and answers to ensure that you receive the most up-to-date content. With each update, you can expect to access new questions, providing you with fresh opportunities to enhance your skills and knowledge. We are here to help you stay current and ensure you have the latest information.

sql interview questions and answers for data analyst

This article will review some interview questions you will likely encounter as you apply for an entry-level data analyst position. Just as there are three formats technical screenings might take, there are also three broad categories of questions you’ll typically be asked during this portion of the interview. Generally speaking, the easier, definitional questions will be fewer and less important than the live coding questions—something to keep in mind as you prepare. Throughout the course, we have carefully curated a mix of basic to advanced ‘mysql interview questions and answers’ to cater to a wide array of students. Each topic is followed by relevant interview questions and detailed answers to solidify your understanding. The practice test wraps up with an exploration of MySQL Dates, MySQL Views, MySQL Data Types, and MySQL Functions, preparing you for all possible ‘mysql interview questions and answers’.

Write a query to display a graph to understand how unsubscribes are affecting login rates over time.

Each row in the table represents an individual product purchase. What does a histogram represent, and what kind of story does it tell? In this case, you are interested in using a histogram to represent the distribution of comments each user has made in January 2020. A histogram with bin buckets of size one means that you can avoid the logical overhead of grouping frequencies into specific intervals. With the department name in place you can now look at the employees of the Engineering team and sort by salary to find the second highest paid.

For example, you could use a window function to calculate the running total of all order totals in your customer orders table. The hardest level involves writing a query for a stated problem. Not only do technical screenings take one of three formats, the questions you’ll typically answer during this portion of the video fall into three broad categories. List the types of statistical calculations you’ve used in the past and what business insights those calculations yielded.

Leave a Reply

Your email address will not be published. Required fields are marked *