SQL Query Validator

Verify syntax integrity and detect structural issues in your SQL statements

VALIDATOR PRO

Validation Result

Sanity-check a query before it reaches your database

Running a broken query is rarely dangerous, but on a slow or shared system it wastes time, and in a deployment script a typo can halt a whole migration. The SQL Query Validator gives you a quick pass or fail on the structural basics, with a plain list of what went wrong when it fails.

Validating a query

Paste your statement into the Query to Validate box using Paste, or type it directly. The Sample button inserts a deliberately broken query so you can see a failure, and Clear empties the box.
Press Validate SQL Syntax.
A result card appears. Green with a check mark means the checks passed; red with a cross lists each structural issue found.

What counts as an issue

Three rules are applied. First, the text must contain a recognizable statement keyword: SELECT, INSERT, UPDATE, DELETE, CREATE, DROP or ALTER, in any letter case. Second, the number of opening parentheses must equal the number of closing ones, and the message shows both counts. Third, single quotes must appear an even number of times, otherwise you are told a quote is unclosed.

Where a quick validation is handy

Reviewing a pull request that contains raw SQL and wanting a fast mechanical check.
Verifying a migration script line by line before running it in staging.
Checking a query written by an analyst who is new to SQL.
Confirming that generated SQL from a script has not been truncated.

How much a pass really means

Be careful with the green card, which says the syntax is perfectly valid. In practice it only means the three rules above were satisfied. A query with a misspelled clause, a missing FROM, a stray comma or an unknown column can still pass. The keyword rule is a substring match, so a name like updated_at or a word inside a comment satisfies it, and statements such as TRUNCATE, MERGE or GRANT that contain none of the listed keywords are reported as invalid. Parentheses and quotes are counted wherever they appear, including inside string literals, so a legitimate string with one bracket can trigger a false failure. Treat the tool as a first filter, then confirm with your database's own parser or an EXPLAIN on a test copy. The checks run in your browser.

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Frequently Asked Questions

What does the validator actually check?

It checks three things: the presence of a keyword like SELECT or INSERT, equal numbers of opening and closing parentheses, and an even count of single quotes. It does not parse the full grammar of the statement.

If the result is green, will my query definitely run?

No. A green result only means those three checks passed. A typo in a keyword, a missing FROM, a wrong column name or a dialect problem can still cause an error when the query runs on your database.

Why did valid SQL fail validation?

Common causes are a statement without any of the listed keywords, such as TRUNCATE or GRANT, or a string literal containing a lone parenthesis or an apostrophe. The counts include text inside quotes and comments.

Are keywords case-sensitive?

No. The keyword search ignores letter case, so select, Select and SELECT are all recognized. It does search for the letters anywhere in the text, including inside longer words and column names.

Can I validate several statements at once?

You can paste several, and the same three checks are applied to the whole text as one block. The result will not tell you which statement caused an issue, so validate long scripts in smaller pieces.