Some SQL mistakes are worth catching before a statement reaches a console, and they are usually the boring ones.
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SQL Validator
Sql
Free · API · MCPToolYour platform
Use SQL Validator three ways
The free SQL Validator on this page works in your browser. The same workflow is available via REST API for apps and via MCP for Cursor, Claude, and other agents — one API key, one plan, one quota. This tool is part of the developer-apis module under Developer Tools.
- Free in browserUse SQL Validator here — no account required.
- REST APICall from your server with
X-Api-Key. - MCP for agentsConnect Cursor or Claude to ToolYour MCP with the same key.
- 1. Get an API keySign in and open Dashboard → API Keys (works for REST and MCP).
- 2. Call or connectUse the REST API from your server, or paste the MCP URL into your agent config.
- 3. Same qualityOutput matches the free web tool across all three surfaces.
What is SQL Validator?
Some SQL mistakes are worth catching before a statement reaches a console, and they are usually the boring ones. This SQL validator runs four structural checks: the statement is not empty, opening and closing parentheses balance, only one statement is present rather than several stacked behind a semicolon, and a recognised verb such as SELECT, INSERT, UPDATE, DELETE, CREATE, ALTER, DROP, or WITH appears.
Every result carries an explicit limitation, and it is the point of the tool rather than a footnote: there is no database connection, no schema knowledge, and no dialect awareness. A clean result means nothing obviously structural is wrong — it does not mean the query is valid, that the tables exist, or that it is safe to run. Only your engine can tell you that. Once the structure checks out, SQL Formatter makes the statement readable for review.
Browser use is free and needs no signup. The same job runs over REST at POST https://api.toolyour.com/api/v1/developer-apis/sql-validator and over MCP at https://api.toolyour.com/mcp — one API key, one shared monthly credit pool, 1 credit per successful call.
What are common questions about SQL Validator?
Does it connect to my database?
Never. There is no connection, no credentials, and no schema access. The checks are purely textual.
What exactly does it check?
Empty input, balanced parentheses, whether multiple statements are stacked behind a semicolon, and whether a recognised SQL verb is present.
Does a clean result mean my query is valid?
No. It means nothing obviously structural is wrong. Column names, joins, types, and dialect syntax are all still unverified.
What are the key features of SQL Validator?
Four structural checks
Emptiness, parenthesis balance, stacked statements, and a recognised verb.
Limitation returned with every result
The response states that no database was consulted, so callers cannot over-read a pass.
Safe in automation
Findings come back as a list rather than an exception, which keeps CI and agent scripts simple.
How do you use SQL Validator?
Paste the statement
A generated query, a migration, or something assembled by string concatenation.
Read the findings
Fix unbalanced parentheses or an accidental second statement before going further.
Verify on the engine
Run EXPLAIN on the real database, which is the only authoritative check.
Why the stacked-statement check matters
Detecting more than one statement behind a semicolon looks pedantic until you think about where the SQL came from. Concatenated query strings are the classic injection surface, and a payload that terminates the intended statement and appends its own is the textbook attack. Seeing two statements where you expected one is a strong signal that interpolation went somewhere it should not have.
It is a signal, not a defence. The real fix is parameterised queries, where user input can never become SQL structure regardless of what it contains. Treat a stacked-statement finding as a prompt to check how the string was built.
Layers of SQL checking
Three layers, in increasing order of authority. Structural — this tool, catching obviously broken text in milliseconds with no connection. Readability — SQL Formatter, which makes the statement reviewable so a person can spot a missing join predicate. Semantic — your database, via EXPLAIN or a dry run against a schema copy, which is the only place column names, types, and dialect rules are truly known.
Use the cheap layers to fail fast in CI and agent loops, and never let a pass at layer one substitute for layer three.
Which formatter and utility tools sit in this cluster?
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