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SQL Validator

Paste one statement or a whole script. Each statement is parsed for your dialect and the first syntax error is pinned to its line and column, before the query ever reaches your database.

Syntax check vs. running the query

A syntax checker answers one question: is this valid SQL for the dialect? It catches missing commas, unbalanced parentheses, misplaced clauses and typos in keywords. It cannot tell you that a column doesn’t exist, that a join multiplies rows, or that a query is slow; for those you need the real database and EXPLAIN. Clauses must appear in a fixed order (SELECT … FROM … WHERE … GROUP BY … HAVING … ORDER BY … LIMIT), and most errors are that order being broken or a comma sitting just before a keyword.

Fixes for the errors people hit most

  • Unexpected FROM: a trailing comma after the last selected column.
  • Unexpected end of statement: an unclosed parenthesis or quote, or a clause with nothing after it.
  • Unexpected “order” / “user” / “group”: a reserved word used as a name. Quote it ("order", `order` or [order] depending on dialect) or rename it.
  • Unexpected “`” in PostgreSQL: backticks are MySQL-only; use double quotes.

Checking one database? There are dialect pages with their own pitfalls: MySQL, PostgreSQL, SQL Server (T-SQL), SQLite, MariaDB, BigQuery, Snowflake, Amazon Redshift.

Once it parses, make it readable with the SQL formatter. Unsure of a clause? The SQL cheat sheet has a working example of each.

Questions

What does the SQL validator check?

It parses your SQL with a grammar for the chosen dialect (the open-source node-sql-parser project) and reports the first syntax error in each statement with its line and column. It checks syntax only: it cannot know whether your tables and columns exist, because it never connects to a database.

Why does valid SQL sometimes show an error?

No offline grammar covers every vendor extension. Very new syntax, stored procedure bodies, and some DDL options may be reported as errors even though your database accepts them. If you are confident the statement is right, run it inside a transaction on a development database to confirm.

Is it safe to paste production queries?

Yes. Validation runs in your browser; the query is not uploaded. Only the “Explain & fix with AI” button sends the failing statement and its error message to an AI model.

What are the most common SQL syntax errors?

A missing comma between columns, a trailing comma before FROM, unbalanced parentheses or quotes, a reserved word used as a column name without quoting (order, user, group), a misspelled keyword, and dialect-specific quoting (backticks in PostgreSQL, double quotes for strings in MySQL ANSI mode).

Can it check my query against my schema?

A pure syntax check can’t. For valid statements the checker lists every table and column the query touches, so you can compare them against your schema at a glance. For a full check, run EXPLAIN on a development database: it fails if any name is wrong, without running the query.

How do I check SQL syntax without running it?

Use an offline parser like this one, or ask the database to plan without executing: EXPLAIN in PostgreSQL, MySQL and SQLite, or SET PARSEONLY ON (syntax only) and SET NOEXEC ON (compile only) in SQL Server.

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