Relational Algebra Calculator | Database Query Tool

Mastering Relational Algebra

Relational Algebra is the mathematical foundation of modern relational databases like SQL. It provides a theoretical framework for manipulating table data using operators. This Relational Algebra Calculator allows you to practice, test, and visualize these operations without setting up a database server.

Supported Operations

• Selection (σ): Filters rows based on a condition. Syntax: σ condition (Relation). Example: σ age > 20 (Students).
• Projection (π): Selects specific columns. Syntax: π col1, col2 (Relation). Example: π name, id (Students).
• Natural Join (⨝): Joins two tables on common columns. Syntax: R ⨝ S.
• Cartesian Product (×): Combines every row of R with every row of S. Syntax: R × S.
• Union (∪): Combines rows from two tables (must have same schema).
• Difference (-): Rows in R that are not in S.
• Rename (ρ): Renames a relation or columns. Syntax: ρ NewName (R).

How to Use This Tool

1. Define Relations: On the left sidebar, add tables. Enter data in CSV format (first row as headers).
2. Write Query: Use the query bar. Click the symbol buttons to insert special characters like π or σ.
3. Run & Export: Click "Run Query" to see the result table. You can then download it as a CSV file.

Why Use a Simulator?

Learning SQL often hides the underlying logic of query execution. By using a Relational Algebra Simulator, you understand how the database engine optimizes and processes data step-by-step. This is essential for Computer Science students and backend engineers aiming for optimization mastery.

Frequently Asked Questions