Online SQL Editor and Query Tool

Free online SQL editor with query execution, table results, and syntax highlighting. Perfect for learning SQL, testing queries, and database development practice.

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Features

SQL Execution

Execute SQL queries with SQLite in your browser

Query Results

View query results in a formatted table layout

Syntax Highlighting

SQL syntax highlighting and auto-formatting

Error Detection

Immediate SQL syntax error detection

Sample Databases

Pre-loaded sample databases for practice

Query History

Track and reuse previous SQL queries

Frequently Asked Questions

How to get started with SQL queries?

Let's start with basic SQL queries:

-- Basic SELECT statement
SELECT * FROM users;

-- Filtering with WHERE
SELECT name, email
FROM users
WHERE age > 21;

-- Sorting results
SELECT name, created_at
FROM users
ORDER BY created_at DESC;

Use our sample databases to practice different queries. The editor provides syntax highlighting and immediate feedback on query results.

How to create and modify tables in SQL?

Learn table creation and modification:

-- Create a new table
CREATE TABLE users (
    id INTEGER PRIMARY KEY,
    name TEXT NOT NULL,
    email TEXT UNIQUE,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
);

-- Insert data
INSERT INTO users (name, email) VALUES
    ('John Doe', 'john@email.com'),
    ('Jane Smith', 'jane@email.com');

-- Modify table structure
ALTER TABLE users
ADD COLUMN age INTEGER;

Practice these commands in our editor with immediate results.

How to join tables in SQL?

Explore different types of joins:

-- INNER JOIN example
SELECT orders.id, users.name
FROM orders
INNER JOIN users ON orders.user_id = users.id;

-- LEFT JOIN example
SELECT users.name, orders.id
FROM users
LEFT JOIN orders ON users.id = orders.user_id;

-- Multiple joins
SELECT orders.id, users.name, products.title
FROM orders
JOIN users ON orders.user_id = users.id
JOIN products ON orders.product_id = products.id;

Experiment with different join types in our editor.

How to use SQL aggregate functions?

Master aggregate functions and grouping:

-- Basic aggregations
SELECT 
    COUNT(*) as total_users,
    AVG(age) as average_age,
    MAX(salary) as highest_salary
FROM users;

-- Grouping results
SELECT 
    country,
    COUNT(*) as user_count,
    AVG(age) as avg_age
FROM users
GROUP BY country;

-- Using HAVING
SELECT 
    department,
    AVG(salary) as avg_salary
FROM employees
GROUP BY department
HAVING AVG(salary) > 50000;

Practice these aggregate functions in our editor.

How to optimize SQL queries?

Learn query optimization techniques:

-- Create an index
CREATE INDEX idx_email ON users(email);

-- Use specific columns instead of SELECT *
SELECT id, name, email
FROM users
WHERE email LIKE '%@company.com';

-- Analyze query performance
EXPLAIN QUERY PLAN
SELECT *
FROM users
WHERE email = 'test@example.com';

Our editor helps you practice writing efficient queries with real-time execution feedback.

How to handle SQL transactions?

Learn transaction management:

-- Start a transaction
BEGIN TRANSACTION;

-- Withdraw from first account
UPDATE accounts
SET balance = balance - 100
WHERE id = 1;

-- Deposit to second account
UPDATE accounts
SET balance = balance + 100
WHERE id = 2;

-- If everything is OK, commit the transaction
COMMIT;

-- If there's an error, rollback
-- ROLLBACK;

Practice transaction management in our safe, sandboxed environment.