SQL Syntax Checker
Validate your SQL queries with our free online syntax checker. No data is sent to our servers, all validation is done in your browser.
Try one of these examples based on the Sakila database:
Your SQL syntax is valid for the selected dialect.
{{ parseError }}
View SQL Abstract Syntax Tree (AST)
{{ astJson }}Frequently Asked Questions
What SQL dialects are supported?
This tool supports multiple SQL dialects including:
- MySQL
- MariaDB
- PostgreSQL
- SQLite
- BigQuery
- Hive
- Transact-SQL (SQL Server)
- Redshift
- DB2
- Snowflake
The validation rules adjust based on the dialect you select from the dropdown menu.
Is my data secure when using this tool?
Yes, your SQL queries are completely secure. All syntax validation happens entirely in your browser. No data is sent to our servers or stored anywhere. This is a client-side tool that runs exclusively in your browser's JavaScript engine.
What kind of errors can this tool detect?
This tool can detect SQL syntax errors such as:
- Missing keywords or clauses
- Incorrect JOIN syntax
- Missing commas between columns
- Unmatched parentheses
- Incorrect statement termination
- Invalid SQL keywords for the selected dialect
It's important to note that this tool checks syntax only, not semantics. It can't verify if table or column names exist in your actual database, or if your query will produce the expected results.
What is the Abstract Syntax Tree (AST)?
An Abstract Syntax Tree (AST) is a structured representation of your SQL query that shows how the parser understands your code. When you write a valid SQL query, it gets parsed into this tree structure that shows the relationships between different parts of your query.
The AST can be helpful for advanced users who want to understand how their query is interpreted by the database engine. It breaks down your query into its component parts (SELECT statements, WHERE clauses, JOIN conditions, etc.) in a hierarchical format.
Can I use this tool offline?
This web-based tool requires an internet connection to load initially. For offline SQL validation, consider using Beekeeper Studio, our desktop application that includes built-in SQL validation and works completely offline.
Why doesn't my query validate even though it works in my database?
There could be several reasons:
- You might be using non-standard SQL extensions specific to your database that aren't recognized by the parser
- You might have selected a different SQL dialect than the one your database uses
- Some databases are more lenient with syntax than standard SQL specifications
- The query might use database-specific functions or features not supported by the parser
If you're sure your query is valid for your specific database, try selecting the closest matching dialect or modifying your query to use more standard SQL syntax.
About This SQL Syntax Checker
Our SQL syntax validator helps you identify syntax errors in your SQL queries before you run them against your database. This tool supports multiple SQL dialects including MySQL, PostgreSQL, SQLite, and more.
Features
- Multi-dialect support: Validate against different SQL flavors
- Syntax highlighting: Makes your SQL more readable
- Privacy-focused: All validation happens client-side in your browser
- AST visualization: See how your SQL is parsed into an Abstract Syntax Tree
How It Works
This tool uses the open-source node-sql-parser library to parse and validate your SQL. The parser converts your SQL into an Abstract Syntax Tree (AST), which is a way to represent the syntax of your query in a structured format.
If your SQL is valid, you'll see a success message. If there are syntax errors, you'll see details about what went wrong and the exact location will be highlighted in the editor.
Example Queries
The example queries use the Sakila sample database, which is a standard MySQL sample database that models a DVD rental store. It contains tables for films, actors, customers, rentals, and more. The examples demonstrate both valid SQL queries and common syntax errors.
Beekeeper Studio: Open Source Database GUI
If you work a lot with databases, you should check out Beekeeper Studio, a free open source desktop app for working with all kinds of databases. It's available for Mac, Linux, and Windows and includes a full-featured SQL editor with syntax checking.