PostgreSQL Exercises VS SQL query for CSV

• Free and accessible
  PostgreSQL Exercises is completely free to use with no registration required, making it highly accessible to anyone who wants to practice SQL skills without any financial barrier.
• Interactive practice environment
  The site provides a built-in SQL query editor where users can write and execute queries directly in the browser against a real database, getting immediate feedback on their results.
• Progressive difficulty
  Exercises are well-organized into categories (basic, joins, aggregation, date, string, recursive) and progress from simple to complex, allowing learners to build their skills incrementally.
• Realistic dataset
  The site uses a realistic country club management scenario with interconnected tables, giving learners practice with a coherent and relatable data model rather than abstract or disconnected examples.
• Detailed solutions and explanations
  Each exercise comes with a detailed expected result set and a thorough explanation of the solution, helping learners understand not just what the answer is but why it works.

Possible disadvantages

• Limited dataset scope
  The entire site relies on a single small dataset (a country club with members, facilities, and bookings), which limits exposure to diverse data modeling patterns and real-world complexity.
• No user progress tracking
  Since there is no account system or registration, the site does not track user progress, making it difficult for learners to pick up where they left off or monitor their improvement over time.
• PostgreSQL-specific syntax
  The exercises focus specifically on PostgreSQL syntax and features, which may not directly translate to other database systems like MySQL, SQL Server, or Oracle, potentially limiting transferability of learned skills.
• Outdated design and interface
  The website has a dated visual design and user interface that lacks modern UX features such as syntax highlighting, auto-completion, or responsive mobile support, making it less pleasant to use compared to newer platforms.
• Limited number of exercises
  The total number of exercises is relatively small compared to other competitive programming or SQL practice platforms, meaning advanced users may quickly exhaust the available problems.

• Familiarity
  SQL syntax is widely used and familiar to many developers, making it easier for them to query CSV data without learning a new query language.
• Expressiveness
  SQL is a powerful language with a rich set of features, allowing complex queries, joins, and aggregations on CSV data.
• Ad-hoc Analysis
  Users can perform quick and efficient ad-hoc data analysis directly on CSV files without needing to import the data into a database.
• Accessibility
  Online tools like try.csv-query.ca make it easy to query CSV files directly from the browser, increasing accessibility for users.

Possible disadvantages

• Performance Limitations
  Handling large CSV files in memory might lead to performance issues, as CSV files are not optimized for querying compared to databases.
• Limited Data Integrity
  CSV files lack data types and constraints, which can lead to errors or unexpected results when querying data, compared to structured databases.
• Lack of Security
  CSV files can be easily modified or corrupted, and querying them directly may expose sensitive data if not properly managed.
• Resource Intensive
  Running complex queries on large CSV files can be resource-intensive and may not be suitable for environments with limited computational resources.

No analysis of SQL query for CSV yet.

• Learn SQL by Typing It: Three Browser Database Terminals Compared

  Disclosure: I help build these simulators; they are part of 50+ free DevOps games and simulators. For more practice beyond them, SQLBolt and PostgreSQL Exercises are excellent and free, and SQL Murder Mystery is the most fun anyone has... - Source: dev.to / 26 days ago

Tracking SQL query for CSV since Jan 2022.