Codeground AI

Free MySQL Playground Online

A lite SQL playground on live MySQL. Practice JOINs, DDL, and aggregations—no local install.

36 lines
Loading editor…
AI Agentcodeground-coder

Tell the agent what to build

It will inspect your code, think, and propose changes you can Keep or Discard inline.

  • Explain what this code does
  • Refactor this file for readability
  • Add input validation and error handling
  • Switch playground & scaffold Node.js
Enter to send · Shift+Enter for newline · Cmd/Ctrl+L to attach selection
Ready
Ln 1, Col 1
Sql

About this editor

A lite SQL playground on live MySQL. Practice JOINs, DDL, and aggregations—no local install.

Run SELECT, INSERT, UPDATE, multi-table JOINs, and CREATE TABLE with AUTO_INCREMENT against a real MySQL sandbox when you lack Workbench or the CLI. Handy for homework, cert prep, and validating queries before staging. Save titled snippets to share examples with teammates.

Key features

Actual MySQL

Commands run against a sandbox MySQL instance.

Results below the editor

Run a query and read the output in the panel underneath.

Skip local setup

No Docker image, no cloud account, no MySQL install on your machine.

Practice queries

Try CRUD, joins, or shell syntax before an interview or a prod change.

Save examples

Bookmark a useful query by saving it with a title.

Sandbox only

Data can reset between sessions. Not for production workloads.

Getting started

  1. 1
    Write SQL

    Start from the users/orders JOIN template, or paste SELECT/DDL of your own.

  2. 2
    Execute

    Result sets or errors appear below the editor.

  3. 3
    Schema

    CREATE TABLE with AUTO_INCREMENT and ALTER within sandbox limits.

  4. 4
    JOINs & EXPLAIN

    Build multi-table queries and inspect plans with EXPLAIN.

  5. 5
    Share

    Save with a title for teammates or interview notes.

Sample queries

Users + orders JOIN

CREATE TABLE users (
  id INT AUTO_INCREMENT PRIMARY KEY,
  name VARCHAR(100) NOT NULL
);
CREATE TABLE orders (
  id INT AUTO_INCREMENT PRIMARY KEY,
  user_id INT NOT NULL,
  total DECIMAL(10,2),
  FOREIGN KEY (user_id) REFERENCES users(id)
);
INSERT INTO users (name) VALUES ('Ada'), ('Bob');
INSERT INTO orders (user_id, total) VALUES (1, 42.00), (1, 18.50), (2, 9.99);
SELECT u.name, SUM(o.total) AS spent
FROM users u
JOIN orders o ON o.user_id = u.id
GROUP BY u.name;

EXPLAIN a JOIN

EXPLAIN
SELECT u.name, o.total
FROM users u
JOIN orders o ON o.user_id = u.id
WHERE o.total > 10;

Window-style ranking (MySQL 8+)

SELECT user_id, total,
       ROW_NUMBER() OVER (PARTITION BY user_id ORDER BY total DESC) AS rn
FROM orders;

Common questions

Is this MySQL compiler free?

Yes. No payment and no account required for a quick run. Sign in if you want saves tied to your profile.

Do I need to install anything?

No. Code runs on Codeground servers in a sandbox. Just open the page.

What MySQL version runs here?

MySQL in a sandbox — sessions may reset.

Can I share my code?

Save with a title to get a permalink, or share the playground URL as-is.

Works for interviews?

Yes. Share a ground link, or use interview mode for a live shared editor.

Multiple files?

This page is for single-file snippets. Use a cloud workspace for full projects.

Will my code still be here tomorrow?

Anonymous sessions can reset. Save with a title (and sign in) for a stable link.

Why use this instead of installing locally?

Good for quick tests, learning, and sharing a snippet. For large offline work, a local IDE still wins.

Is this an online MySQL IDE or playground?

A browser playground with syntax highlighting and one-click Run — run MySQL online without a full local install. Cloud workspaces cover multi-file projects.

Is there a free MySQL playground with no install?

Yes. Run MySQL SQL online for free—no local server, Workbench, or mysql client download for basic practice.

MySQL playground vs DBeaver / Workbench?

Workbench and DBeaver manage real servers with full DBA features. This lite SQL playground is for JOINs, DDL drills, and interview prep without installing anything.

Can I practice JOINs and AUTO_INCREMENT tables?

Yes. Create multi-table schemas with AUTO_INCREMENT PKs, insert rows, and JOIN them in one session.

Can I use EXPLAIN here?

Yes. Run EXPLAIN on sandbox queries to see access paths before you change production indexes.

Does the sandbox reset?

Data may not persist forever. Save titled snippets for lasting templates; this is practice only.

Good for MySQL interview prep?

Yes. Drill multi-table JOINs, aggregations, and EXPLAIN in a free online MySQL playground.