The Contoso database is a sample database created by Microsoft to help learn and develop applications in the Microsoft SQL Server environment. It is used as a sample data set to showcase Microsoft Business Intelligence products and DW/BI capabilities across the entire Microsoft Office product line. The data set includes information about company departments such as C-levels, Sales/Marketing, IT, Finance, and supports mapping integration, providing both OLTP (Online Transaction Processing) and OLAP (Online Analytical Processing) data, along with reference data and dimensions. The Contoso database includes tables such as Customer, Order, OrderDetail, and Product, each containing different information about the company's customers, orders, order details, and products. These tables have relationships with each other, allowing for complex and powerful data queries. For example, a customer can have many different orders, and each order can have many different order details. These data can be used for data analysis, visualization, and training of predictive and classification models. In education, Contoso is often used as an example to teach concepts in many fields such as databases, application development, and systems management.

The AdventureWorks database is a sample database developed by Microsoft to help users better understand Microsoft technologies and learn how to use them to develop applications. This database is designed for SQL Server, but can also be used with other database management systems such as Oracle, MySQL, PostgreSQL. AdventureWorks is set on a fictional company called AdventureWorks Cycles, a large-scale bicycle manufacturing and trading company. This database contains tables, views, and procedures related to customer management, product management, order management, and other transactions, used to illustrate objects in online task processing (OLTP). The AdventureWorks database provides complex functions such as data processing with transactions and combining data from multiple tables in the database. In addition, AdventureWorks has notable features such as using data constraints to protect data integrity, using indexes to optimize data access performance, and using triggers to automatically perform actions when data is added, modified, or deleted. These features make AdventureWorks a very useful sample database for developers and database administrators. AdventureWorks datasets can be used for data analysis, visualization, and training of predictive and classification models. AdventureWorks is also used in many courses, certifications, and training in database administration, database design, and application development.

The WideWorldImporters database is an important resource for developers and database administrators to learn and practice new features of SQL Server and Azure SQL Database. It is also a wholesale database that contains a wealth of information about the import and export of goods. With new features and technologies of SQL Server, this database allows for multiple joins, in-memory processing of data, and full-text search. The data tables in the WideWorldImporters database provide detailed information about different aspects of a wholesale company's business. The main objects include customers, orders, products, warehouses, suppliers, and employees. In addition, this database also contains other important objects such as accounts, addresses, invoices, and shipping charges. Analyzing data in the WideWorldImporters database can help developers and database administrators gain a better understanding of a wholesaler’s business and find opportunities to optimize performance and business growth. The WideWorldImporters database is developed in the T-SQL language and can be used on a variety of operating system platforms, including Windows and Linux. This allows developers and database administrators to use the database on a variety of systems to develop and deploy applications. Additionally, the database can also be used in the cloud via Azure SQL Database and Azure SQL Managed Instance to provide easier scalability and data management.

The Chinook database was developed to help students and teachers learn and practice database management skills. With tables such as artists, albums, media tracks, invoices, and customers, Chinook provides a practical and easy-to-understand approach to database management in the music retail industry. The Chinook database was created by Jeff Richter and released under the MIT license, allowing users to freely use and modify the database according to their needs. The Chinook database is available for many different database management systems, including SQL Server, Oracle, MySQL, and more. The Chinook database is also considered an alternative to the Northwind database, which is also a popular sample database used for learning and training in database management. However, Chinook provides more information about the music retail industry and can be used to develop real-world applications in the industry.

Sakila is a database widely used in database management education and training. This database is developed by MySQL and includes tables for managing movie lists, employees, customers and DVD copies of movies. Sakila has many tables such as actor, film, category, customer and rental. It is designed to help learners and developers practice database management skills, from database design, creating queries to optimizing performance. Sakila also provides several reporting systems and script files to help users practice and better understand this database. Since Sakila is a free sample database, it is available for many different database management systems, including MySQL, SQL Server and PostgreSQL. This makes it easy and quick for learners and developers to access the database to practice and develop their skills in the field of database management.

Northwind Database is a famous Microsoft database that contains data on the commercial activities of a virtual company called Northwind, which specializes in importing and exporting food products. The tables in this database will be a classic example for the sales problem and are widely used in learning and training database administration. The Northwind database provides tables to manage product lists, orders, suppliers, customers and employees. It is designed to help learners practice database management skills, such as database design, query creation and performance optimization. The Northwind database includes tables such as Products, Orders, Suppliers, Customers and Employees. It can be used to practice skills such as SQL programming, data processing and database design. In addition, Northwind also provides a number of reporting systems to help users better understand the database and practice data analysis skills. The Northwind database has been used by Microsoft for many years to showcase new features of SQL Server and other database technologies. Northwind is no longer officially supported by Microsoft, but it is still widely used in education and training.

World Database MySQL is a sample database that comes with the MySQL relational database management system. It is designed to be a practical example database for learning and practicing SQL (Structured Query Language) queries. The World Database MySQL database includes 3 tables city, country, countrylanguage containing information about countries, their cities and other related information such as population, region, continent, etc. These tables can be used to practice SQL queries, for example, searching for countries with a population above a certain threshold, or searching for cities within a certain country. In addition, World Database MySQL is also widely used in MySQL courses and documents to help learners master the skills of working with relational databases.

QlikView is a dataset used in the QlikView application, a software for visualizing and analyzing data. This dataset is organized in the form of tables and linked together through common fields (key fields) to form a relational data structure. QlikView dataset includes sample datasets such as Sales, Inventory, Human Resources, which are provided in the software for users to easily practice and learn. In addition, users can also create and use their own datasets in QlikView to visualize and analyze data. All datasets in QlikView are designed to allow users to perform complex data queries, create reports, charts and visual data models to help users better understand data and make more accurate business decisions.