sql case study questions and answers

Step 2: Develop a Hypothesis for the SQL Case Question. In order to visualize this, we'll need to plot two lines on a 2D graph. The x-axis represents days until unsubscribing with a range of -30 to 0 to 30, in which -30 is thirty days before unsubscribing and 30 is 30 days after unsubscribing. The y-axis represents the average login rate for ...

The solution involved using the Case expression within an SQL query to assign each customer to a category based on their total spend. Here's a simplified version of the code: SELECT CustomerID, CASE. WHEN SUM (PurchaseAmount) > 10000 THEN 'High'. WHEN SUM (PurchaseAmount) BETWEEN 5000 AND 10000 THEN 'Medium'.

Example Datasets. All datasets exist within the dannys_diner database schema - be sure to include this reference within your SQL scripts as you start exploring the data and answering the case study questions.. Table 1: sales. The sales table captures all customer_id level purchases with an corresponding order_date and product_id information for when and what menu items were ordered.

Easy SQL Scenario Based Interview Questions. Easy SQL scenario based interview questions will test your ability to apply simple queries and solve basic problems. There will be limited use of subqueries or multiple tables. 1. Write a query to display the highest salaries in each department.

8-Week SQL Challenges. This repository serves as the solution for the 8 case studies from the #8WeekSQLChallenge. It showcases my ability to tackle various SQL challenges and demonstrates my proficiency in SQL query writing and problem-solving skills. A special thanks to Data with Danny for creating these insightful and engaging SQL case ...

Case study questions and answers/solutions for #8WeekSQLChallenge by Danny Ma. This repository contains all of my SQL submissions for the #8WeekSQLChallenge created by Danny Ma. In the summer of 2022 I completed Danny's Challenge and I found it to be the best SQL exercises found on the web. Many times I had to review other peoples work to ...

A comprehensive collection of SQL case studies, queries, and solutions for real-world scenarios. This repository provides a hands-on approach to mastering SQL skills through a series of case studies, including table structures, sample data, and SQL queries. - GitHub - tituHere/SQL-Case-Study: A comprehensive collection of SQL case studies, queries, and solutions for real-world scenarios.

Database design. Expect questions on normalization, denormalization, and the differences between various SQL statements like DELETE, TRUNCATE, and DROP. Advanced queries. You may be asked about subqueries, both nested and correlated, as well as how to perform specific tasks like finding the nth highest value in a column.

SQL Practice Queries. Practice queries on Select, Where, Limit, Order by, Aggregates, Group by, Joins, Sub-queries and Case expressions. Solve over 80 SQL exercises using real life case studies. Write queries in MySQL syntax. Please login to see the progress.

Case Study - Sales Analysis of E-commerce Platform. Enhance SQL skills while analyzing a comprehensive dataset to gain insights into e-commerce sales and customer behavior, enabling data-driven decision-making for optimizing the online marketplace. Problem Name. Status.

5 essential beginner scenario-based SQL interview questions with answers. To review your applicants' responses, use these straightforward sample answers to our scenario-based SQL interview questions. 1. Another employee needs help and asks you to explain what a database is.

Source: Case Study #1 — Danny's Diner — 8 Week SQL Challenge — Start your SQL learning journey today! Amidst the aroma of freshly brewed coffee and sizzling bacon at Danny's Diner lies a story untold — the tale of how this humble establishment harnessed the power of SQL. Explore with me in the first case study out of the 8-Week SQL ...

View answer. 5. Assume a schema of Emp ( Id, Name, DeptId ) , Dept ( Id, Name). If there are 10 records in the Emp table and 5 records in the Dept table, how many rows will be displayed in the result of the following SQL query: Select * From Emp, Dept.

Familiarize yourself with the following popular systems: SQL Server: Microsoft's robust and widely-used database management system. MySQL: A popular open-source database system known for its speed and flexibility. PostgreSQL: A powerful open-source relational database system with advanced features.

Basic-Level SQL Interview Questions. Basic Level Questions (15 Questions) 1. What is SQL? Answer: SQL (Structured Query Language) is a standard programming language used to manage and manipulate relational databases. 2. What is a Primary Key? Answer: A primary key is a unique identifier for a record in a table, ensuring uniqueness and preventing NULL values.

Start with 20 Basic SQL Questions for Practice. Below are some of the most commonly asked SQL query questions and answers for practice. Get a timer to track your progress and start practicing. Q-1. Write an SQL query to fetch "FIRST_NAME" from the Worker table using the alias name <WORKER_NAME>. Ans.

However, for sushi, each $1 spent earns 20 points. From Day 1 to Day 7 (the first week of membership), each $1 spent for any item earns 20 points. From Day 8 to the last day of January 2021, each ...

Jul 9, 2023. 18. Completing the Danny Ma Data Bank Challenge was an exhilarating journey that pushed my skills and knowledge to new heights. This project stands out as the most challenging and ...

Oct 5, 2021. 183. 6. I started Danny Ma's SQL challenge to gain hands-on experience as a beginner in this vast SQL field and it has not disappointed me! So let's get started. You can find in ...

This repository contains solutions for #8WeekSQLChallenge, they are interesting real-world case studies that will allow you to apply and enhance your SQL skills in many use cases. I used Microsoft SQL Server in writing SQL queries to solve these case studies.

All of the 8 Week SQL Challenge case studies can be found below: Case Study #1 - Danny's Diner. Case Study #2 - Pizza Runner. Case Study #3 - Foodie-Fi. Case Study #4 - Data Bank. Case Study #5 - Data Mart. Case Study #6 - Clique Bait. Case Study #7 - Balanced Tree Clothing Co. Case Study #8 - Fresh Segments.

Danny seriously loves Japanese food so in the beginning of 2021, he decides to embark upon a risky venture and opens up a cute little restaurant that sells his 3 favourite foods: sushi, curry and ...

The sum of that CASE statement will be the numerator. The denominator will be a COUNT of all elements in the event_type column. CAST(SUM(CASE WHEN event_type IN ('video call received', 'video call sent', 'voice call received', 'voice call sent') THEN 1 ELSE 0 END) AS FLOAT) / COUNT(event_type) Next, we'll wrap the conditional in a GROUP BY ...

SQL is a versatile language for data analysis, and these real-world case studies demonstrate its practical application in various domains. By using SQL queries, you can extract valuable insights ...