How to use the SQL Validator
- Choose your database dialect (MySQL, PostgreSQL, SQL Server, SQLite, BigQuery and more).
- Paste or open your SQL — several statements separated by semicolons are fine.
- Errors show the line, column and the expected tokens, with the faulty spot marked.
- Valid statements are listed with their type and the tables they touch, plus warnings for risky patterns.
What does a SQL validator check?
A SQL validator (or syntax checker) parses your query with the grammar of a specific database and tells you whether it is well formed: balanced parentheses, keywords in the right order, valid expressions, commas between columns and so on. This one splits your script into statements, parses each one separately so you see every broken statement at once, and points at the line and column where parsing stopped.
Best-practice warnings
| Warning | Why it matters |
|---|---|
UPDATE / DELETE without WHERE | Changes every row in the table — usually a mistake. |
SELECT * | Fetches columns you may not need and breaks when columns are added or reordered. |
INSERT without a column list | Depends on column order; adding a column breaks it. |
LIKE '%…' | A leading wildcard cannot use a normal index and scans the table. |
= NULL | Never true; use IS NULL. |
ORDER BY without LIMIT in a subquery, or LIMIT without ORDER BY | Row order is not guaranteed without an explicit sort. |
Dialect differences that cause errors
- Identifier quotes — MySQL and MariaDB use backticks (
`order`), PostgreSQL, SQLite and the SQL standard use double quotes, SQL Server uses square brackets ([order]). - Row limits —
LIMIT 10in MySQL, PostgreSQL and SQLite;TOP 10orOFFSET … FETCHin SQL Server. - Upserts —
ON DUPLICATE KEY UPDATE(MySQL) vsON CONFLICT … DO UPDATE(PostgreSQL, SQLite) vsMERGE(SQL Server, Snowflake, BigQuery). - Casts — PostgreSQL accepts
value::int; most others needCAST(value AS INT).
Make the query readable with the SQL formatter, generate statements from data with CSV to SQL or JSON to SQL, and design tables with the CREATE TABLE generator.
Tools that pair well with the SQL Validator
- MySQL Syntax Checker — Validate MySQL queries before you run them.
- PostgreSQL Syntax Checker — Validate PostgreSQL queries in your browser.
- Excel to JSON — Open an .xlsx workbook or paste cells straight from Excel or Google Sheets and get clean JSON.
- JSON to Excel — Turn a JSON array into a real Excel workbook.
Frequently asked questions
Is my SQL sent to a server or a database?
No. The query is parsed in your browser with the open-source node-sql-parser grammar. Nothing is uploaded and nothing is executed.
Does a valid result mean the query will run?
It means the syntax is valid for the selected dialect. The validator does not know your schema, so a misspelt table or column name, missing permissions or type mismatches only show up when the database runs it.
Why does the error point after my mistake?
A parser reports the first token it cannot fit into the grammar. A misspelt keyword such as
WHER is often read as an alias, so the error appears on the next word. Check the token just before the marked position too.Which statements are supported?
SELECT (with joins, subqueries, CTEs, window functions, UNION), INSERT, UPDATE, DELETE, REPLACE, CREATE / ALTER / DROP TABLE, CREATE INDEX and VIEW, TRUNCATE, USE and more, depending on the dialect. Stored procedures and vendor-specific procedural blocks are not fully covered.