SQL Online Compiler | Free Online Compiler

SQL

CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT, role TEXT);
INSERT INTO users (name, role) VALUES ('Asha', 'Admin'), ('Noah', 'Editor'), ('Lia', 'Viewer');
SELECT * FROM users;

Results

What Is the SQL Online Compiler?

This tool lets you write and execute SQL queries directly in your browser using an in-browser SQLite database engine. There is nothing to install and no server-side execution. Your queries run entirely in your browser using sql.js, a WebAssembly port of SQLite.

SQL (Structured Query Language) is the standard language for managing and querying relational databases. This online compiler is ideal for learning SQL syntax, practicing queries, and testing database operations like creating tables, inserting data, joining tables, and running aggregate functions.

Because the database runs in your browser, execution is instant. Each time you click Run, a fresh SQLite database is created, your SQL statements are executed in order, and the results are displayed as formatted tables in the output panel.

How It Works

Write your SQL statements in the editor panel. You can include multiple statements separated by semicolons, such as CREATE TABLE, INSERT, and SELECT.
Click the Run button to execute your SQL. The sql.js engine creates a fresh in-memory SQLite database, runs all your statements sequentially, and captures the results.
View the results in the Results panel. Each SELECT query that returns rows is displayed as a formatted table with column headers and row counts.
Modify and re-run as needed. Since the database resets on each run, you can freely experiment with different schemas and data without worrying about leftover state.

Step-by-Step Example

Suppose you want to create a products table and run some queries on it. Here is how you would do it:

First, type the following SQL into the editor panel:

CREATE TABLE products (
    id INTEGER PRIMARY KEY,
    name TEXT NOT NULL,
    category TEXT,
    price REAL
);

INSERT INTO products (name, category, price) VALUES
    ('Laptop', 'Electronics', 999.99),
    ('Headphones', 'Electronics', 79.50),
    ('Desk Chair', 'Furniture', 249.00),
    ('Notebook', 'Office', 4.99),
    ('Monitor', 'Electronics', 349.00);

SELECT category, COUNT(*) as count, ROUND(AVG(price), 2) as avg_price
FROM products
GROUP BY category
ORDER BY avg_price DESC;

Click the Run button. The engine creates the table, inserts the data, and runs the aggregation query. The Results panel displays:

Result 1 (3 rows)
| category    | count | avg_price |
|-------------|-------|-----------|
| Electronics | 3     | 476.16    |
| Furniture   | 1     | 249.00    |
| Office      | 1     | 4.99      |

Use Cases

Learning SQL fundamentals. Practice SELECT, INSERT, UPDATE, DELETE, and DDL statements in a safe environment that resets on every run.
Practicing JOINs and subqueries. Create multiple related tables and test INNER JOIN, LEFT JOIN, subqueries, and common table expressions.
Testing aggregate functions. Experiment with COUNT, SUM, AVG, MIN, MAX, GROUP BY, and HAVING clauses on sample datasets.
Preparing for SQL interviews. Many technical interviews include SQL questions. Practice writing queries with immediate visual feedback.
Prototyping database schemas. Quickly test table designs, constraints, and relationships before implementing them in a production database.

Limitations and Notes

SQLite engine only. This compiler uses SQLite, which has some differences from MySQL, PostgreSQL, SQL Server, and Oracle SQL in syntax and feature support.
No persistent storage. The database is created fresh on each run. All tables and data are lost when you click Run again or refresh the page.
No stored procedures. SQLite does not support stored procedures, triggers with complex logic, or user-defined functions in this environment.
No file import or export. You cannot load data from CSV files or export query results. Use INSERT statements to populate tables.
SQLite type system. SQLite uses dynamic typing with five storage classes (NULL, INTEGER, REAL, TEXT, BLOB) rather than strict column types.
Browser memory limits. Very large datasets may be constrained by your browser's available memory.

Frequently Asked Questions

What SQL engine does this compiler use?

It uses sql.js, which is SQLite compiled to WebAssembly and running entirely in your browser.

Is the database persistent?

No, the database resets on every page refresh. All tables and data are created fresh each time you run your queries.

Can I use CREATE TABLE?

Yes, you can create tables, insert data, and query them all in a single execution. The database starts empty each run.

Do JOINs work?

Yes, all JOIN types supported by SQLite are available, including INNER JOIN, LEFT JOIN, and CROSS JOIN.

Can I use stored procedures?

No, SQLite does not support stored procedures. This is a limitation of the SQLite engine, not this tool.

Can I create indexes?

Yes, you can create indexes on your tables using standard CREATE INDEX syntax.

What data types are supported?

SQLite uses dynamic typing with five storage classes: NULL, INTEGER, REAL, TEXT, and BLOB.

Can I import data from a file?

No, file import is not supported. You need to use INSERT statements to populate your tables with data.

SQL Compiler