SQL Visual Debugger

Why did this SQL query return these rows?

SQL Visual Debugger shows how your SQL query builds its result step by step inside VS Code, so you can see what changed at each stage instead of guessing from the final output.

See rows load, filter, join, group, aggregate, sort, deduplicate, branch through CASE, flow through CTEs and subqueries, and more.

Works with MySQL, PostgreSQL, SQL Server, and SQLite.

Help shape the next update

A major SQL Visual Debugger update is being explored, including remote connections, AI debugging help, richer intermediate results, query comparison, and broader SQL syntax support.

Vote for what matters most and join the waitlist:

Help shape the next SQL Visual Debugger update

Try it in 30 seconds

No database ready? Use the built-in SQLite demo playground.

1. Open the Command Palette.
2. Run SQL Visual Debugger: Open Demo Playground.
3. Step through the sample query with Next and Previous.

Use it on your own SQL

1. Open a .sql file.
2. Select one supported SELECT query, or place your cursor inside it.
3. Right-click and choose SQL Visual Debugger: Debug Query.
4. Connect to your local database if prompted.
5. Step through the visual result.

Best for

• debugging confusing SELECT queries
• learning SQL execution order
• teaching JOIN, WHERE, GROUP BY, aggregation, and query flow
• explaining query results to teammates

What it shows

• FROM, JOIN, WHERE, GROUP BY, HAVING, SELECT
• DISTINCT, ORDER BY, LIMIT / TOP
• CASE expressions
• window functions
• CTEs and supported subqueries
• row-count changes between steps
• visual explanations for complex clauses

Safety

SQL Visual Debugger is built for read-only debugging.

• Runs supported read-only SELECT and WITH query shapes
• Blocks non-read-only SQL before execution
• Uses local database connections only
• Keeps passwords only in session memory

Current boundaries

SQL Visual Debugger is focused on supported SELECT-style analysis queries. Some advanced SQL shapes are intentionally limited today, including UNION, recursive CTEs, remote database hosts, non-equality joins, and some advanced subquery/window-function syntax.

When a query is outside the supported visual-debugging shape, the extension stops with a clear message instead of pretending to debug it.

Telemetry and privacy

Anonymous telemetry helps improve reliability and prioritize future support.

Telemetry never includes SQL query text, table names, column names, database names, credentials, hostnames, result data, file paths, or location fields.

Telemetry can be disabled with:

SQL Visual Debugger: Disable Telemetry

Feedback and issues

Found a bug or have feedback? Open an issue in the SQL Visual Debugger feedback repository.