Check your SQL for syntax errors before executing. Validate queries against MySQL, PostgreSQL, SQLite, and MariaDB dialects.
Enter SQL to validate
Stop guessing if your query will run. Validate your SQL syntax instantly against multiple database dialects before executing it in production.
Comprehensive validation for MySQL, PostgreSQL, SQLite, and MariaDB dialects.
Deep syntax analysis using Abstract Syntax Tree parsing to catch subtle structural errors.
Get immediate error reporting with line numbers and helpful suggestions for fixes.
Writing SQL is deceptively simple. A missing comma, a misplaced parenthesis, or using a keyword that is reserved in PostgreSQL but valid in MySQL can cause your entire application to crash. Our SQL Syntax Validator acts as your first line of defense, analyzing your code against the grammatical rules of strict SQL before you ever run it.
"Why not just run it and see if it fails?" This "trial by error" approach is risky:
How does this tool know your SQL is wrong? It doesn't just look for keywords. It builds an Abstract Syntax Tree (AST).
SELECT [DISTINCT] column_list FROM table_ref.SQL is a standard, but every database implements it differently. Our tool helps you navigate these quirks:
| Feature | MySQL / MariaDB | PostgreSQL | SQL Server |
|---|---|---|---|
| Quoting Identifiers | Backticks: `table` | Double Quotes: "table" | Brackets: [table] |
| String Concatenation | CONCAT(a, b) | a || b | a + b |
| Limit Rows | LIMIT 10 | LIMIT 10 | TOP 10 (in Select) |
Yes. We support CTEs (Common Table Expressions), nested subqueries, window functions (`OVER PARTITION BY`), and complicated `JOIN` logic. If it's valid standard SQL, we likely support it.
This usually happens if you're using a very new database feature (like DuckDB extensions) or a specific stored procedure syntax that our parser doesn't yet recognize. Try simplifying the query to isolate the issue.
No. This tool checks syntax (grammar), not semantics (meaning). We don't have access to your database schema, so we can't know if a table named `users` actually exists in your DB. We only check that you referred to it correctly.
Just like our other tools, validation happens entirely in your browser using JavaScript. No SQL code is sent to our servers.