Check SQL syntax before execution. Validate MySQL, PostgreSQL, SQLite, and MariaDB queries online with instant parser feedback.
Your MySQL query is syntactically correct.
These tools sit next to each other in the workflow. The validator answers “is this grammar even valid?”, while formatting and execution answer different questions afterward.
Use this when you want to know whether the SQL is grammatically shaped correctly for the chosen dialect.
Use formatting when the SQL is valid enough to read but still messy enough to hide mistakes in structure.
Use Playground when the next question is not grammar anymore but whether the query returns the rows you expect.
Many validator searches come from one practical question: “Why is this query failing?” A good landing page should show both the broken pattern and the corrected version.
Invalid SQL
SELECT
customer_id,
SUM(amount) total_revenue
FROM orders
WHERE status = 'completed'
GROUP customer_id;GROUP customer_id is not valid grammar here. The parser expects GROUP BY customer_id, so the statement fails before execution.
Valid SQL
SELECT
customer_id,
SUM(amount) AS total_revenue
FROM orders
WHERE status = 'completed'
GROUP BY customer_id;Once GROUP BY is written correctly, the validator can treat the query as grammatically sound and you can move on to checking business logic instead.
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.
You might ask, “Why not just run it and see if it fails?” That kind of “trial by error” approach is risky:
UPDATE or DELETE statement with a broken WHERE clause could modify more records than intended. Validation ensures the structure is essentially sound (though logic must still be verified).TOP in MySQL instead of LIMIT). A unified validator helps you catch these dialect-specific errors.How does this tool know your SQL is wrong? It does not just look for keywords. It builds an Abstract Syntax Tree (AST).
SELECT id FROM and breaks it into [SELECT, KEYWORD], [id, IDENTIFIER], [FROM, KEYWORD].SELECT statements might be: SELECT [DISTINCT] column_list FROM table_ref.SELECT FROM table (missing columns), the parser knows that the grammar expects a column_list after SELECT but found FROM instead. It flags this as an "Unexpected Token" error.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. The validator can parse many common SQL patterns including CTEs, nested subqueries, window functions, and join-heavy statements.
That usually happens when the SQL relies on a database-specific feature or extension that the parser does not fully support yet.
No. This tool validates SQL grammar, not your live schema, so it cannot confirm whether a referenced table or column actually exists.
Yes. Validation happens in the browser, so the SQL text is not sent to SQL Boy servers during the parser check.
Syntax validation is the first gate, not the last one. It confirms the statement is grammatically shaped for a chosen dialect so you can spend review time on logic and performance instead of broken commas and invalid keywords.
Use the validator as a fast first-pass when query strings are being added to application code and you want to catch basic grammar issues early.
Helpful when you inherit SQL from a ticket, message, or migration note and do not fully trust the syntax yet.
Next Step
Validation only tells you whether the SQL is grammatically shaped for a dialect. The next move is usually execution, cleanup, or a route change to a more relevant part of the site.
Choose Playground when the next question is whether the query returns the rows you expect.
Open PlaygroundCleanupMove here when the parser errors are solved and you want a more readable structure before shipping the query.
Open SQL FormatterRoute meOpen Start Here when the grammar issue points to a broader gap in fundamentals, not just a one-off query fix.
Open Start HereUse this when the query is syntactically valid but still returns the wrong result.
Helpful when your SQL passes validation but still contains risky or inefficient patterns.
Relevant when syntax problems come from templated or programmatically generated SQL.
Important when a syntactically valid query could still be unsafe because user input influenced the final SQL text.
Validation only answers whether the SQL is grammatically shaped for a dialect. These paths connect that parser result to the article that explains the next real problem.
These guides help after parser errors are fixed and you still need to understand the logic or the join structure you inherited.
Use these when validation passes and the real confusion has shifted to aggregation, clause order, or post-aggregation filtering.
Relevant when a parser check is only the first gate for SQL assembled from request parameters, filters, or templates.